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R IceStop Roof and Gutter De-Icing System

Design, Instal lat ion, and Maintenance Guide

BR3554.FNT 7/19/99 1:31 PM Page 2

The IceStop system provides simple design, easy

installation, and complete accessories for roof and

gutter de-icing. Backed by more than 20 years of

Raychem expertise with snow and ice, IceStop is the

solution for a wide range of applications:

• Standing seam roofs

• Sloped roofs and valleys

• Flat roofs

• Gutters and downspouts

• Plastic and metal roofs

• Shake and shingle roofs

• Slate and tile roofs

• Roofs without gutters

IceStop Systems forRoof and Gutter De-Icing

Nickel-copper bus wires

Self-regulating conductive core

Insulating jacket

Tinned-copper braid

Outer fluoropolymer jacket

IceStop Heating CablePerformance

1

Heating Cable Construction

2

3

4

51

2

3

4

5

Self-Regulation

The conductive polymer heatingcore regulates its power output in response to the temperature.

Simple and reliable:

• Can be overlapped.

• Will not burn out.

• Saves energy.

• Will not overheat roofingmaterials or plastic gutters.

Parallel Circuitry

Current flows between the twobus wires independently at eachpoint along the heating cable.

Easy to design and install:

• Easily accommodates fieldrouting changes.

• Can be teed and spliced toaccommodate downspouts.

TemperatureSelf-regulating

power output

BR3554.FNT 7/19/99 1:41 PM Page 3

Contents

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1OverviewSafety Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1Codes and Approvals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1IceStop System Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Design Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3How to Use These Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3Step 1. Heating Cable Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Layout Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3Sloped Roof—Nonstanding Seam . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4Sloped Roof—Standing Seam . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5Flat Roof . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6Sloped Roof without Gutters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7Valleys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8Roof/Wall Intersections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8Gutters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9Downspouts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Step 2. Attachment Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11Roof Attachment Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Mechanical Attachment Clips . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12Adhesive Attachment Clips . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13Belt Loop Approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14Alternate Attachment Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Attachment Methods for Other Areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15Gutters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15Downspouts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16Heated Drip Edges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16Drip Loops . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Step 3. Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18Controller Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Automatic Moisture/Temperature Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . 19Ambient Thermostat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19Manual Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20Typical Wiring Schematics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Step 4. Component Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21Step 5. Electrical Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Determine the Number of Circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Installation Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24Heating Cable Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24Heating Cable Damage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24Heating Cable Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24Component Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25Controls and Feed Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25Test Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Insulation Resistance (Megohmmeter) Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25Continuity Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Operation and Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27System Start-up and Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27Periodic Inspection/Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27Roof/Gutter Repair and Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Appendix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30A. IceStop Heating Cables Data Sheet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30B. Condensed CSI Specification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31C. IceStop System Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33D. Design Worksheet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

IceStop SystemDesign, Installation,and Maintenance Guide

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IceStop SystemDesign, Installation,and Maintenance Guide IntroductionOverview

This guide provides complete design and installation instructions for an IceStop system that willprovide drain paths for the following applications:

• Roofs made from all types of standard roofing materials, including shake, shingle, rubber, tar,wood, metal, and plastic.

• Gutters made from standard materials, including metal, plastic, and wood.

• Downspouts made from standard materials, including metal and plastic.

The guide does not provide information for using an IceStop system for the following applications:

• Preventing snow movement on roofs—IceStop will not keep snow or ice from falling off theroof. IceStop is designed to remove melt water, not accumulated snow. Snow fences or snowguards should be used to eliminate snow movement.

For the names of manufacturers of snow guards or snow fences, contact your Raychemrepresentative, or contact Raychem directly at (800) 545-6258.

• Melting snow off a roof and/or reduction of snow load—IceStop is designed to remove meltwater, not accumulated snow.

If your application conditions are different, or if you have any questions, contact your Raychemrepresentative, or contact Raychem directly at (800) 545-6258.

Safety GuidelinesThe safety and reliability of any heat-tracing system depends on the quality of the productsselected and the manner in which they are installed and maintained. Incorrect design, handling,installation, or maintenance of any of the system components could damage the de-icing systemor the roof and may result in inadequate de-icing, electric shock, or fire. To minimize these risksand to ensure that the system performs reliably, read and carefully follow the information,warnings, and instructions in this guide.

This symbol identifies particularly important safety warnings that must be followed.

Codes and ApprovalsInstallation of an IceStop system is governed by Article 426 of the National Electrical Code (NEC)and Part I, Clause 62-300, of the Canadian Electrical Code (CEC). Raychem, the NEC, and theCEC all require the use of ground-fault protection of equipment to reduce the risk of fire causedby damage or improper installation. All installations must also comply with applicable local codesand standards.

The IceStop roof and gutter de-icing system is UL Listed, CSA Certified, and FM Approved foruse in nonhazardous areas. It is also FM Approved for use in Class I, Division 2 hazardouslocations.

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Introduction

IceStop System DescriptionIce dams can cause water ingress into buildings and generate dangerous icicles. An IceStop systemcan help prevent ice dams and icicles by maintaining a continuous path for melt water to drainfrom the roof. As long as a heated path from the roof to a safe discharge area is maintained, icedams will not form. The IceStop system can be used on roofs and valleys and in downspoutsand gutters made from all types of standard roofing materials, including metal, plastic, wood,shake/shingle, rubber, and tar.

The IceStop system is intended to provide drain paths. A typical system includes the following:

Downspout Hanger KitEnd Seal Kit Tee Kits

Heating Cable

Controller

Power Connection Kits Attachment KitsSplice Kits

®

R

LISTED

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IceStop SystemDesign, Installation,and Maintenance Guide Design Guidelines

How to Use These GuidelinesWhen using the IceStop Design and Installation Guide, follow these steps:

1. Determine the cable layout for the roof, gutters, and downspouts—Step 1 below.

2. Determine the attachment methods you will use—Step 2, page 11.

3. Select the type of control you will use—Step 3, page 18.

4. Select components and accessories—Step 4, page 21.

5. Determine electrical requirements—Step 5, page 23.

After you have reviewed this guide, use the Design Worksheet on pages 35 and 36 to complete the design of your project.

Step 1. Heating Cable LayoutLayout OverviewHeating cable layout depends primarily on the roof type. The following sections show typicallayouts on standard roof types.

Roof type/area Page

Sloped Roof—Nonstanding Seam 4

Sloped Roof—Standing Seam 5

Flat Roof 6

Sloped Roof without Gutters 7

Valleys 8

Roof/Wall Intersections 8

Gutters 9

Downspouts 10

Important: The heating cable must be in contact with snow or ice to work effectively. Do notinstall the heating cable under the roofing or the roofing materials.

Figures 1.1 and 1.2 below illustrate several important terms:

Tracingwidth

Tracingheight

12"

Area where ice dams are most likely to form

Eave overhang

Exterior wall

Heating cable

Gutter

Roof

Heated area

Figure 1.1 Front view of roof with IceStop system. Figure 1.2 Side view of roof with IceStop system.

ClipsDownspouthanger

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IceStop SystemDesign Guidelines

Sloped Roof—Nonstanding SeamFor sloped roofs, ice dams may form at the roof edge. To maintain a continuous path for melt waterrunoff, route the heating cable in a serpentine pattern as shown in Figure 1.3 below and follow theappropriate attachment recommendations in Step 2. Additional heating cable may be needed forother gutters, downspouts, and valleys.

Figure 1.3 Layout in a serpentine pattern.

• Run heating cable up the roof until it is 12 inches past the exterior wall into the heated area(see Figure 1.2 on page 3).

• Install the heating cable on the roof in a serpentine pattern as shown in the illustration above.

• Be sure that the heating cable extends all the way down to meet with the run of heating cablein the gutter. This will ensure that you have a continuous path where the melted water can flow.Attach the heating cables together with UV-resistant cable ties.

• Use Table 1.1 to determine how much heating cable to use per foot of roof edge. This willdetermine how much heating cable you need to trace on the roof. Additional heating cable willbe needed for gutters, downspouts, and component connections.

Table 1.1 IceStop Heating Cable Length for Roof De-icing

Eave overhang Tracing Tracing Feet of heating cable distance width height per foot of roof edge

12" 2' 24" 3.1'

24" 2' 36" 4.2'

36" 2' 48" 5.2'

None 2' 12" 2.0'

Note: Attachment methods are purposely not shown in Figure 1.3. For attachment methods,proceed to Step 2 (page 11).

Other Considerations• Use a snow fence or snow guards (not shown) to prevent snow from sliding. Extend heating

cable above the snow fence at least 6 inches.

• If there are no gutters, refer to “Heated Drip Edges” in Step 2 (page 16) for information onhow to install heating cable for this application.

• It is not always necessary to run heating cables on the roof. If you do not experience ice damson the roof, installing heating cables only in the gutters and downspouts may be sufficient.

2'

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Sloped Roof—Standing SeamFor sloped standing-seam metal roofs, ice dams may form at the roof edge. To maintain acontinuous path for melt water to run off, route the heating cable along the seams as shown inFigure 1.4 and follow the attachment recommendations in Step 2. Additional heating cable may beneeded for gutters, downspouts, and valleys.

Figure 1.4 Layout on a standing seam roof.

• Run the heating cable up the seam until it is 12 inches past the exterior wall and into a heatedarea (see Figure 1.2 on page 3).

• Run the heating cable up one side of the seam, loop it over to the other side, and return it tothe bottom of the gutter. Continue along the bottom of the gutter to the third seam and repeatthe process (see Figure 1.4). If the seams are more than 24" apart, trace every seam.

Table 1.2 IceStop Heating Cable Length for Standing Seam Roofs

Eave overhang Standing seam Tracing Feet of heating cabledistance spacing height per foot of roof edge

12" 18" 24" 2.8'24" 18" 36" 3.6'36" 18" 48" 4.3'12" 24" 24" 2.4'24" 24" 36" 2.9'36" 24" 48" 3.6'

• On standard systems, the length of heating cable needed for the roof and gutter can bedetermined by the formula:

Heating cable length = [2 x no. of seams traced x (trace height + distance from roof edge togutter bottom)] + distance along the gutter/roof edge

Additional heating cable will be needed for component connections and downspouts.

Note: Attachment methods are purposely not shown in Figure 1.4. For attachment methods,proceed to Step 2 (page 11).

Other Considerations• Use a snow fence or snow guards (not shown) to prevent snow from sliding. Extend heating

cable above the snow fence at least 6 inches.

• If the roofing materials continue down the fascia, contact your local Raychem representativeor Raychem directly for design assistance.

• If there are no gutters, refer to “Heated Drip Edges” in Step 2 (page 16) for information onhow to install heating cable for this application.

• It is not always necessary to run heating cables on the roof. If you do not experience ice damson the roof or roof damage, installing heating cables only in the gutters and downspouts may besufficient.

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Flat RoofIce dams may occur on flat roofs at the edge flashing and at drains. Flat roofs are typicallypitched toward drains and these paths often become obstructed by snow and ice. To maintain acontinuous path for melt water to run off, route the heating cable as shown in Figure 1.5 andfollow the appropriate attachment recommendations in Step 2. Additional heating cable may beneeded for downspouts.

Figure 1.5 Layout on a flat roof.

• Place heating cable around perimeter.

• Trace valleys from perimeter to drain.

• Extend heating cable into internal downspouts at least 12 inches into heated space.

• External downspouts and scuppers must be treated carefully. A path must be provided for thevalley/perimeter heating cable to the point of discharge (see Figure 1.13 on page 10).

• To avoid damage, do not walk on the heating cable.

Junctionbox

DrainSlope

Ice can form around drain and at roof edges where adjacent snow thaws during the day and refreezes at night.

Heating cable provides a continuous heated path to allow melt water to run off the roof before it refreezes.

Heating cable should be positioned around the perimeter and in the valleys of a flat roof. The heating cable must extend into the drain orscupper to allow the melt water to exit the roof.

Scupper

Drip loop

6


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Sloped Roof without GuttersWhen gutters are not used on a building, ice dams may form at the roof edge. To maintain acontinuous path for melt water to run off, a drip loop or heated drip edge may be used. Driploops and drip edges allow water to drip free of the roof edge.

Route the heating cable as shown in Figure 1.6 or 1.7 below and follow the appropriate attachmentrecommendations in Step 2. Additional heating cable may be needed for valleys.

Figure 1.6 Layout for heated drip loops.

Figure 1.7 Layout for heated drip edge.

Note: Attachment methods are purposely not shown in the above illustrations. For attachmentmethods, proceed to Step 2.

Other Considerations• Use a snow fence or snow guards to prevent snow from sliding (not shown). Extend heating

cable above the snow fence a minimum of 6 inches.

• Ice will build up on the surfaces below the drip loop or drip edge if gutters are not used.

• Ice may also build up on the vertical surfaces if there isn’t a sufficient overhang or if there is astrong wind. Use of a gutter system will prevent this ice buildup.

IceStopheatingcable

2"–3"(5–8 cm)

7


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ValleysIce dams may form at the valley on a roof where two different slopes meet. To maintain acontinuous path for melt water, run the heating cable up and down the valley as shown in Figure 1.8and follow the appropriate attachment recommendations in Step 2. Additional heating cable maybe needed for the roof surface, gutters, and downspouts.

Figure 1.8 Layout for a valley.

• Trace two-thirds of the way up each valley with a double run of heating cable (loop up andback once).

• The heating cable must extend into the gutter. If you don’t have gutters, the heating cableshould extend over the edge 2 to 3 inches to form a drip loop.

• For attachment methods, proceed to Step 2 (page 11).

Roof/Wall IntersectionsRoof/wall intersections can be treated in the same manner as valleys. Snow has a tendency tocollect at this interface. Providing a loop of heating cable two-thirds of the way up the slope willprovide a path for the extra melt water in this area to escape.

Figure 1.9 Layout for a roof/wall intersection.

• Extend a loop of heating cable two-thirds of the way up the slope adjacent to the wall.

• Position the closest heating cable approximately 2 to 3 inches from the wall. Position thesecond heating cable 4 to 6 inches from the first.

2"–3"

4"–6"

1/3

2/3

2/3

1/3

8


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GuttersIce may accumulate in gutters and at the roof edge. To maintain a continuous path for melt water torun off, route the heating cable as shown in Figure 1.10 below. Additional heating cable may beneeded for the roof surface, downspouts, and valleys.

Figure 1.10 Layout in standard gutters—up to 6" wide.

• Use one run of heating cable in the gutter.

• No attachment to gutter is normally required. If attachment is desired, use a roof clip such as aRaychem GMK-RC clip.

• Continue heating cable down the inside of the downspout. See “Downspouts” on page 10 formore information.

In wide gutters, snow and ice can bridge over the tunnel created by a single heating cable andprevent melt water from getting into the gutter and downspouts. To maintain a continuous path formelt water to run off, run the heating cable in the gutter as shown in Figure 1.11 below and followthe appropriate attachment recommendations in Step 2. Additional heating cable may be needed forthe roof surface, downspouts, and valleys.

Figure 1.11 Layout in wide gutters—6" to 12" wide.

• Use two parallel runs of heating cable. Separate the two runs of heating cable with a pair ofGMK-RC clips or a single GM-RAKE downspout hanger bracket.

• No attachment to the gutter is normally required. If attachment is desired, use a GMK-RC withappropriate adhesive.

• Continue heating cable down the inside of the downspout. See “Downspouts” on page 10 formore information.

6" spacingmaximum

GM-RAKE

GMK-RC

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DownspoutsIce may form in downspouts and prevent melt water from escaping from the roof. To maintain acontinuous path for melt water to run off, run the heating cable inside the downspout to the endas shown in Figures 1.12 and 1.13 below. Follow the appropriate attachment recommendationsin Step 2. Additional heating cable may be needed for the roof surface, gutters, and valleys.

Figure 1.12 Heating cable at top of downspout.

Figure 1.13 Heating cable at bottom of downspout.

• If the downspout ends underground, the heating cable should extend into a heated area orbelow the frost line.

• For low-water-flow situations, teeing the heating cable so that a single run goes down thedownspout is usually sufficient. For high-water-flow situations, where ambient temperaturesoften fall below –10°F (–23°C), or where it isn’t convenient to tee the heating cable, use tworuns—by running the heating cable down to the bottom and then back to the top.

• Leave drip loops below the downspout at bottom.

• If a single run of heating cable is used, the end seal should be looped back up at least 12 inchesinside the downspout.

• If the downspout ends near the ground, water will refreeze on the ground and build up aroundthe downspout, eventually blocking the opening.

Other Considerations

• Do not leave the end seal exposed at the end of the downspout.

Drain removes melt waterbelow the frost line.

Accumulated icemay block drains.

Accumulated icecan be removed.

12"

10


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Step 2. Attachment Methods

Heating cable attachment depends primarily upon the roof type. The following table shows therecommended attachment methods for typical roof materials and roof areas.

Table 2.1 Attachment Methods for Typical Roofs

Recommended AlternateRoof material attachment method attachment method

Shake/shingle Mechanical clips (page 12)

Rubber/membrane Belt loop (page 14) Adhesive clips (page 13)

Metal Adhesive clips (page 13) Mechanical clips (page 12)Belt loop (page 14)

Wood Mechanical clips (page 12)

Other Alternative (page 15)

Area Attachment method

Gutters Attachment not generally required (see page 15)

Downspouts Downspout hangers (page 16)

Drip edges Attached to a flat sheet or standard drip edge, or installed in formed sheetmetal (see page 16)

Component locations Drip loops (page 17)

Roof edges with nogutter Drip loops (page 17)

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Roof Attachment MethodsMechanical Attachment ClipsOne of the most common attachment methods is to use Raychem’s GMK-RC mechanical clip. Itcan be used on all surfaces that can be nailed or screwed into.

Figure 2.1 GMK-RC clip attachment.

• The GMK-RC roof clips are used to secure IceStop heating cable. This multipurpose bracketattaches with a screw, nail, or adhesive to many types of roofs and gutters.

• After determining the heating cable layout, fasten the clips to the roof before installing theheating cable in the bracket. If using nails or screws, apply sufficient water-sealing materialaround the clips and nails or screws to prevent roof leaks.

• Thread the heating cable into the clips. Use additional clips wherever the heating cable may besubject to abrasion from movement.

• Use pliers to close the clamps, but be careful not to crush the heating cable.

• One box of 50 GMK-RC clips is sufficient to attach the heating cable on 35 feet of roof edgeusing a serpentine layout. Your layout may require additional clips.

• For layouts other than the standard serpentine, use one clip for each 5 to 10 feet of unsupportedheating cable and at every change of heating cable direction.

• For nonstanding-seam sloped roofs, the loops of heating cable being serpentined on the roofshould be attached, using a UV-resistant cable tie, to the heating cable run in the gutter.

• For standing-seam roofs, the heating cable should be cable-tied together at the bottom of theseam.

12


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Adhesive Attachment ClipsFor roofs where penetrating attachments are not desired, use the GMK-RC clip attached byadhesive.

Figure 2.2 GMK-RC clip on standing seam roof.

Figure 2.3 GMK-RC clip on flat roof.

• The GMK-RC roof clips are used to secure IceStop heating cable. The clip attaches withadhesive (not supplied by Raychem) to many types of roofs and gutters.

• Several different adhesives are recommended by Raychem. See Table 4.2 on page 21 or contactRaychem for alternatives.

• On a standing seam roof, use four clips on each seam being traced. On a flat surface, use oneclip for every 5 to 10 feet of unsupported heating cable and at every change of direction.

• Follow all recommendations from the adhesive manufacturer with regard to cleaning andpreparing the roof surface for the adhesive.

• After determining the heating cable layout, fasten the clips to the roof with the adhesive andallow the adhesive to cure before installing the heating cable.

• Thread the heating cable through the clips. Use additional clips wherever the heating cablemay be subject to abrasion from movement.

Note: How well the adhesive holds can be strongly affected by how well the surface to which it willadhere is prepared and by what type of adhesive is used. Be sure to follow the recommendations ofthe adhesive manufacturer.

00485_Raychem_6-3-99 7/19/99 12:20 PM Page 13

Belt Loop ApproachWith the belt loop approach, strips of roofing materials are fastened to the roof using standardmeans for that particular type of roof. The heating cable is attached with a UV-resistant cable tieto the loop formed by this material.

Figure 2.4 Belt loop approach on a sloped roof.

Figure 2.5 Belt loop approach on a flat roof.

• The belt loop method of securing the IceStop heating cable involves using a small piece ofroofing material to form a “belt loop.”

• Use at least one belt loop for every 5 to 10 feet of unsupported heating cable and at everyheating cable change of direction.

• After determining the heating cable layout, fasten each end using standard means for thatparticular type of roof. Examples of this would be attaching with solder on a copper roof,adhesive on a membrane roof, or tar on an asphalt roof.

• The heating cable is attached with a UV-resistant cable tie to the loop formed by this material.

• Use additional clips wherever the heating cable may be subject to abrasion from movement.

Strip of roofmaterial

Roofadhesive

Cable tie

Heatingcable

14


00485_Raychem_6-3-99 7/19/99 12:20 PM Page 14

Alternate Attachment MethodsRaychem’s attachment clips were developed as an easy way to provide enough support for theheating cable without crimping, crushing, or otherwise damaging the heating cable and withoutapplying any chemicals or adhesives directly to the heating cable. Other means may be used toattach the heating cable as long as they:

• Do not crush, crimp, cut, or otherwise damage the heating cable. Damage to the heating cablecould cause the system to fail, resulting in electric shock or fire.

• Do not apply adhesives or other chemicals directly to the heating cable. Many adhesives willnot stick to the outer jacket, which could cause the attachment method to fail and could resultin inadequate de-icing.

• Provide enough strength to support the heating cable on the roof and any load from snow thatcollects on the system. If the attachment method is not strong enough, the heating cablecould come loose and fall off.

One method sometimes used is to attach the heating cable with a UV-resistant cable tie to abracket, rod, or cable that is installed to support the heating cable. The brackets, rods, or cablesare then attached to the roof through whatever means are appropriate for the situation and cansupport the weight of the heating cable.

Attachment Methods for Other Areas

Gutters

The IceStop heating cable is not normally attached to the gutter.

Figure 2.6 GMK-RC clip in a gutter.

• Attachment is not generally required for standard gutters. If attachment is desired, such as inhigh-wind areas, use GMK-RC adhesive-mounted attachment clips. Several different adhesivesare recommended by Raychem. See Table 4.2 on page 21.

• For large gutters (6 to 12 inches wide), use two runs of heating cable separated by GMK-RCroof clips. It is not necessary to attach the clips to the gutter. Use one pair of GMK-RC roofclips for every 10 feet.

6" spacingmaximum

GM-RAKE

GMK-RC

15


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16


DownspoutsThe IceStop heating cable needs to be attached at the top of each downspout, using one GM-RAKEdownspout hanger per heating cable. The GM-RAKE downspout hanger clamps around the heatingcable and attaches to the fascia with a screw or nail.

Figure 2.7 GM-RAKE downspout hangers.

• GM-RAKE downspout hangers protect the heating cable from damage from sharp edges andalso provide support for the weight of the heating cable.

• Use two GM-RAKE downspout hangers for double-traced downspouts.

• Attach the GM-RAKE downspout hangers to the structure with a nail or other suitable method.

Heated Drip EdgesWhen installing a heated drip edge, you can attach the heating cable to the roof’s drip edge or to a flatsheet of sheet metal with a UV-resistant cable tie, or place the heating cable in a formed (J-channel)piece of sheet metal.

Figure 2.8 Heated drip edge attachment guidelines.

• The illustrations above are guidelines for heating cable attachment in a heated drip edgeapplication. Raychem does not manufacture drip edge attachment clips.

• Use 20-gauge or thicker corrosion-resistant sheet metal.

• Contact your Raychem representative or Raychem directly for specific recommendations.

Roofing material

Metal drip edge

IceStop heating cable

UV-resistant cable tie

UV-resistant cable tie

Attached to flat sheet

Installed in a formed sheet

Attached to standard drip edge

2 3/4"

1/4"

3/4"

00485_Raychem_6-3-99 7/19/99 12:20 PM Page 16

Drip LoopsDrip loops are used where components are located in the system, and at roof edges where nogutter is installed. The idea in each case is to allow water to drip free of the heating cable.

Roof Edge with No GutterWhere no gutter is installed, a drip loop should be installed at the roof edge to allow melt water todrip free of the roof. No special attachment is necessary for heated drip loops. Use the sameattachment as appropriate for your roof type; just make sure the heating cable extends 2 to 3 inches(5 to 8 cm) from the roof edge.

ComponentsDrip loops are used where the heating cable enters a power connection, tee, or splice, to keepwater from tracking into the component. No special attachment is necessary.

17


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18


Step 3. ControlController SpecificationsThree control methods are commonly used with roof de-icing systems:

• Automatic moisture/temperature controller

• Ambient thermostat

• Manual control

All three methods will require contactors if any significant length of heating cable is being used.The contactor must be sized to carry the load. Each method offers a tradeoff of initial cost versusenergy efficiency and ability to provide effective de-icing. If the system is not energized whenneeded, ice will form. If the system is energized when de-icing is not needed, there will beunnecessary power consumption. Choose the control method that best meets the projectperformance requirements. Contact your Raychem representative for details.

For Class I, Division 2 hazardous locations, use an agency-approved controller or thermostatsuitable for the same area use.

Automatic Moisture/Temperature ControllerThe most conservative approach from an energy-consumption point of view is an automaticmoisture/temperature sensor. Raychem supplies an automatic moisture/temperature sensor,which consists of an APS control panel, one or more GIT gutter sensors, and one or more CIT aerial snow sensors. Table 3.1 outlines the options for this approach.

The GIT ice sensor should be mounted in gutters near downspouts. It senses the actualenvironmental conditions, such as temperature and moisture. A GIT sensor is recommended foreach critical area that needs to be monitored for icing conditions (such as when one side of abuilding gets sun in the morning and the other side gets sun in the afternoon, or one side gets theprevailing winds and the other side is protected). A CIT aerial-mounted snow sensor is alsorecommended. Having both gutter and snow sensors allows for snow to begin melting in thegutters at the onset of any snow or ice condition.

Table 3.1 Automatic Moisture/Temperature Controller

Characteristic APS panel GIT sensor CIT sensorType of sensing — Gutter-mounted Aerial-mounted

moisture/temperature moisture/temperatureNumber of sensors 1 to 6 — —Set point — 38°F and moisture 38°F and moistureEnclosure NEMA 4X — —Enclosure limits –40°F to 160°F — —Electrical rating 40 A, 120 Vac — —

40 A, 208 to 240 Vac40 A, 277 Vac

Approvals UL Listed — —CSA Certified

00485_Raychem_6-3-99 7/19/99 12:20 PM Page 18

Ambient ThermostatUsing an ambient sensing thermostat, such as the Raychem AMC-1A or AMC-F5 thermostat, theroof and gutter system will be on when the ambient temperature is below freezing. This willensure the heating cable is energized any time the water might freeze. Table 3.2 outlines thetechnical specifications for the two thermostats.

Table 3.2 Thermostats

Characteristic AMC-F5 AMC-1AType of sensing Air temperature Air temperatureSensor Bulb and 3-ft capillary ProbeSet point range 40°F fixed 15°F to 140°FEnclosure NEMA 4X NEMA 4XDifferential 6°F 6°FSet point repeatability 3°F 3°FEnclosure limits –30°F to 140°F –40°F to 160°FElectrical rating 22 A, 120 to 480 Vac 22 A, 120 to 480 VacApprovals UL Listed, CSA Certified UL Listed, CSA CertifiedRecommended start-up temp. 32°F (0°C) 32°F (0°C)

19


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20


Manual ControlA manually controlled system is operated by a switch that controls the system power contactor.This method requires constant supervision to work effectively.

The type of control you select will affect power consumption and ensure the heating cable is onwhen needed.

Typical Wiring Schematics

Figure 3.1 Typical controller wiring—single circuit.

Figure 3.2 Typical controller wiring—multiple circuits.

Warning: To minimize the danger of fire from sustained electrical arcing if the heatingcable is damaged or improperly installed—and to comply with Section 426-28 of the NationalElectrical Code, and Part I, Clause 62-300, of the Canadian Electrical Code—ground-faultequipment protection must be used on each heating-cable branch circuit. Arcing may not bestopped by conventional circuit protection.

øA øB øC 120-V or 277-V supply

Controller (thermostat or moisture/temperature controller)

RayClic-PC orFTC-P power connection

IceStop cable

NO

NC

C

IceStop cable

IceStop cable

E304 contactor

NA NB NC

ø ø 208-V or 240-V supply with GFPDN ø 120-V or 277-V supply with GFPD

NO

NC

P

IceStop cable

00485_Raychem_6-3-99 7/19/99 12:21 PM Page 20

21


Step 4. Component Selection

A typical IceStop system consists of several components to seal and power the heating cable,and various attachment accessories to attach the heating cable to the roof. The IceStop heatingcable is also supported inside downspouts by using attachment accessories. All of the componentsand accessories work together to provide a safe and reliable de-icing system that is easy toinstall and maintain. The accessories available are listed in Table 4.1, the adhesives in Table 4.2, andcomponents in Table 4.3.

Table 4.1 Attachment Accessories

Catalog Standard Number ofDescription number package packages required

Mechanical GMK-RC 50/box 1 box per 35' of roof(penetrating) edge when serpentine roof clip layout is used

Hanger bracket GM-RAKE 1/box 1 hanger per cable in downspout or as requiredfor mechanical protection

RayClic RayClic-SB-02 1/box 1 mounting bracketwall mounting per RayClic componentbracket (except RayClic-E)

installed on a wall

UV-resistant CT-CABLE-TIE 100/box Varies dependingcable tie on installation

Table 4.2 Adhesives

Approximate DispensingAdhesive Description Color tooling time Cure time equipment

GEGrey RTV167 Neutral-cure Gray 20 minutes 48 hours Caulking gunsilicone adhesive

Adhesive is not supplied by Raychem. It can be purchased through a GE distributor. Contact GEat (800) 255-8886 for the name of a local distributor. Follow manufacturer’s instructions forsurface preparation and installation.

For other adhesives, contact your Raychem representative, or contact Raychem directly at (800) 545-6258.

00485_Raychem_6-3-99 7/19/99 12:21 PM Page 21

22


The self-regulating IceStop heating cable is cut to length at the job site. In order to seal theheating cable from the environment and provide power, Raychem-approved components must beused. A power connection kit is required to attach power to one end of the heating cable. An endseal is required—and is provided with each power connection—to seal the other end. Splice andtee kits are also available to connect two or three heating cables together.

RayClic and FTC components are available for the IceStop system. The RayClic components areinsulation-displacement quick connect systems. The FTC components use heat-shrinkable tubingand crimp barrels. All of these components are outlined in Table 4.3 below.

Table 4.3 Components

Catalog Std. No. of pkgs. Heating-cableDescription number pkg. required allowance1

Power Connection

Quick connect power RayClic-PC 1 1 per circuit 2 ft (0.6 m)connection kit to power one run of heating cable. Includes 1 end seal.

Quick connect power RayClic-PS 1 1 per circuit 2 ft (0.6 m)connection kit to power two runs of heating cable. Includes 2 end seals.

Quick connect power RayClic-PT 1 1 per circuit 3 ft (1 m)connection kit to powerthree runs of heating cable. Includes 3 end seals.

Junction box2 FTC-P 1 1 per circuit 2 ft (0.6 m)mounted HSP powerconnection kit.Includes 1 end seal.

Splice Connection

Quick connect RayClic-S 1 As needed 2 ft (0.6 m)splice kit

Heat-shrinkable FTC-HST 2 As needed 2 ft (0.6 m)splice kit

Tee Connection

Quick connect RayClic-T 1 As needed 2 ft (0.6 m)tee kit

Heat-shrinkable FTC-HST3 2 As needed 2 ft (0.6 m)tee kit

End Seal

End seal RayClic-E 1 As needed 0.3 ft (0.1 m)

1Additional heating cable required for installation. 2Junction box not included. 3One RayClic-E end seal is required for each FTC-HST used as a tee kit.

R

00485_Raychem_6-3-99 7/19/99 12:21 PM Page 22

Step 5. Electrical Design

Determine the Number of Circuits

To determine the number of circuits, you need to know:

• Total heating cable length• Minimum start-up temperature• Voltage

Total heating cable length is the amount of heating cable needed for the entire system. Thisincludes all of the heating cable installed on the roof, in the gutters, and in the downspouts, aswell as the small amounts of extra heating cable needed to install the components.

Choose the start-up temperature based on the lowest temperature at which the system willenergize. Turning the system on at a temperature below the chosen start-up temperature may risktripping the breakers due to start-up currents.

Use Table 5.1 to determine the maximum length of heating cable on one circuit. If the totalheating cable length exceeds the maximum circuit length for the expected start-up temperature,more than one circuit will be required.

Minimum number of circuits = Total heating cable length divided by the maximum circuit length.

Note: Your specific layout may require more circuit breakers than implied by this formula.

Select the smallest appropriate circuit breaker size.

A ground-fault circuit breaker with 30-mA trip level is required by Raychem and by nationalelectrical codes. Use a circuit breaker such as Square D QOEPD, QOB-EPD, or equivalent. Theavailability of 40-amp ground-fault circuit breakers may be limited. For 277-volt applications usea TraceGard 277 GFEPD. See GFEPD Selection Guide (H55476) for information on differentbreakers. Alternate devices providing comparable levels of ground-fault protection may also beacceptable. For technical assistance, contact your Raychem representative, or contact Raychemdirectly at (800) 545-6258.

Warning: Fire Hazard. To minimize the danger of fire from sustained electrical arcing if theheating cable is damaged or improperly installed, and to comply with Raychem requirements andSection 426-28 of the National Electrical Code, and Part J, Clause 62-300, of the CanadianElectrical Code, ground-fault protection must be used on each heating cable branch circuit. Arcingmay not be stopped by conventional circuit protection.

Table 5.1 Maximum Circuit Length in Feet (Meters)

Start-up Circuit breaker size Max.Heating cable temperature 15 A 20 A 30 A 40 A* A/ftGM-1XT at 32°F (0°C) 100 (30) 135 (41) 200 (61) — 0.120120 volts 20°F (–7°C) 95 (29) 125 (38) 185 (56) 200 (61) 0.126

0°F (–18°C) 80 (24) 100 (30) 155 (47) 200 (61) 0.150

GM-2XT at 32°F (0°C) 190 (58) 250 (76) 380 (116) — 0.063208 volts 20°F (–7°C) 180 (55) 235 (72) 355 (108) 380 (116) 0.067

0°F (–18°C) 145 (44) 195 (59) 290 (88) 380 (116) 0.083


0°F (–18°C) 155 (47) 205 (62) 305 (93) 400 (122) 0.077


0°F (–18°C) 165 (50) 225 (69) 330 (101) 415 (126) 0.073

*Only FTC-P power connection, FTC-HST splice/tee, and RayClic-E end kits may be used with 40-amp circuits.

23


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24

IceStop SystemDesign, Installation,and Maintenance Guide Installation Guidelines

This section includes the information you need to install the IceStop system. Follow all of thesteps provided here.

Heating Cable InstallationPrior to starting installation:• Test the heating cable insulation resistance to confirm that the heating cable has not been

damaged during shipping (see “Test Methods” on page 25).• Visually check components for damage. • Make sure that all material is included as indicated on the packing slip.• Make sure that you will be using ground-fault equipment protection devices (GFEPDs) with a

30-mA trip level to power the circuit. Nuisance tripping can occur if you use 5-mA-trip-levelground-fault interrupters (GFIs), even with undamaged heating cable.

• Protect the heating cable ends from moisture and mechanical damage if they will be leftexposed before connection.

• Compare the heating cable received with the design voltage required (for example, GM-1XT for120 Vac, GM-2XT for 208–277 Vac) to ensure the cable is right for your application. This ismarked on each reel and on the heating cable.

• Compare the design circuit lengths with the heating cable lengths received (also marked oneach reel) in order to minimize the need for splicing.

• Ensure that the heating cable required does not exceed the maximum circuit length for the voltageand circuit breaker rating to be used (see Table 5.1, “Electrical Design” on page 23).

Note: The heating cable can be cut to length without affecting its power output per foot.

When installing the heating cable:• Do not pull it over sharp edges.• Do not use excessive pulling force.• Do not kink or crush the heating cable.• Do not walk on the heating cable.• Do not cover the heating cable with any roof materials.

Heating Cable DamageIf physical damage is found, the entire damaged section must be removed and a new section ofheating cable spliced in, using only approved Raychem splice kits. Do not attempt to repair thedamaged heating cable section. If the damage cannot be found, the complete circuit should beremoved and replaced with new IceStop heating cable.

Warning: Shock and Fire Hazard. Damaged heating cable or components can causeelectrical shock, arcing, and fire. Do not attempt to energize damaged heating cable orcomponents. Replace them immediately using a new length of heating cable and theappropriate IceStop accessories.

Heating Cable HandlingStart by installing components and attachment accessories in locations indicated on projectdrawings or as indicated in the Design Guidelines Step 1, “Heating Cable Layout” (pages 3–10).

Once all clips and downspout hangers are in place, and adhesives cured if applicable, the heatingcable can be installed.

Start at the end seal and work back. Be sure to leave a drip loop at components so that water willnot track down the heating cable into the component. Install heating cable using the layoutshown in Step 1 for your application.

• Be sure the heating cable provides a continuous path for water to flow off the roof.

• Be sure to leave drip loops where appropriate.

• Do not exceed the circuit lengths listed in Table 5.1 on page 23.

• Be sure to loop and secure heating cable at the bottom of downspouts so that the heatingcable is not exposed to mechanical damage.

• Install a UV-resistant cable tie wherever two heating cables are intended to stay together.

• Test installed heating cable for insulation resistance and continuity (see Test Methods, pages 25 and 26).

00485_Raychem_6-3-99 7/19/99 12:21 PM Page 24

25

IceStop SystemInstallation Guidelines

Component InstallationOnce all attachment clips, downspout hangers, and heating cables are in place and tested, terminationscan be installed. Install components according to installation instructions included in kits.

Use only appropriate Raychem components as indicated in the Design Guidelines Step 4, “ComponentSelection” (page 21). Never substitute parts.

Visually inspect for mechanical damage and test the entire circuit for insulation resistance prior toapplying power.

Controls and Feed WiringThe controls and feed wiring must be in place prior to system startup.

When installing controls and feed wiring, DO:• Use a 30-mA trip level ground-fault equipment protection device for each circuit.• Power the system with the appropriate voltage.• Add conduit drains at power connections so water does not accumulate in junction boxes.• Be sure the contactor being used is appropriate for the load. If the controller is being used

directly, be sure that it is rated for the load and that all requirements for disconnects are followed.• Test control for proper operation (see “Test Methods” below).

Test Methods

Insulation Resistance (Megohmmeter) TestThe insulation resistance test is critical to ensure the safety and reliability of the heating cablesystem. This test should be performed as part of the installation of the system, and is useful fortroubleshooting an installed system.

Warning: Shock or Fire Hazard. Disconnect power to all circuits prior to testing.

Using a megohmmeter, test insulation resistance at three voltages—500, 1000, and 2500 Vdc.Significant problems may not be detected if the insulation resistance is tested only at 500 or 1000volts. First, measure the resistance between the heating-cable bus wires and the grounding braid;then, if the heating cable is installed on a metal gutter, downspout, and/or metal roof, measure theinsulation resistance between the braid and the metal surface.

Procedure1. Disconnect all power to the heating cable, thermostat, and contactor.2. Set test voltage at 0 Vdc.3. Connect the negative lead (–) to the heating cable metallic braid.4. Connect the positive lead (+) to both heating-cable bus wires.5. Turn on the megohmmeter and set the voltage to 500 Vdc; apply the voltage for

1 minute. Record the resistance.6. Repeat step 5 at 1000 Vdc and 2500 Vdc.7. Turn off the megohmmeter.8. If the megohmmeter does not self-discharge, discharge phase connection to ground with a

suitable grounding rod. Disconnect the megohmmeter.9. If the heating cable is installed on a metal roof, metal gutter, or metal downspout, repeat

these steps with the negative lead (–) connected to the grounding braid and the positive lead (+) connected to the metal roof, gutter, and/or downspout.

10. Reconnect the thermostat or contactor and re-energize the circuit.

Insulation Resistance CriteriaA clean, dry, properly installed circuit should measure thousands of megohms, regardless of theheating cable length or measuring voltage (0–2500 Vdc). The following criteria are provided to assistin determining the acceptability of an installation where optimum conditions may not apply:

• All three insulation resistance values should be greater than 1000 megohms.• Insulation resistance values for any particular circuit should not vary more than 25 percent as

a function of measuring voltage.• Reading must be steady at measuring voltage.• If any of the above conditions are not met, consult the “Troubleshooting” instructions on

pages 28 and 29.

00485_Raychem_6-3-99 7/19/99 12:21 PM Page 25

Continuity TestThe continuity test is useful in determining if the heating cable is damaged or was not connectedcorrectly. This test can be performed as part of the troubleshooting procedure. Note: Some of theheating cable components, such as the end seal kit and power connection, splice, and tee kits,which utilize heat-shrink tubings, are not reenterable and will have to be replaced after this test isdone.

Warning: Shock or Fire Hazard. Disconnect power to all circuits prior to testing.

1. Disconnect all power to heating cable, thermostat, and contactor.2. Twist the two bus wires together at one end.3. Take a resistance reading from bus wire to bus wire at the other end. The reading should be

3 ohms or less. High readings (above 100 ohms) generally indicate bus wire damage ormisconnected components.

4. If there are any tees on the circuit, each leg of the tee must be tested separately.5. Be sure to untwist the bus wires and install new components on the circuit prior to re-energizing

the circuit.6. Reconnect the contactor or thermostat and re-energize the circuit.

26

IceStop SystemInstallation Guidelines

00485_Raychem_6-3-99 7/19/99 12:21 PM Page 26

Operation and Maintenance

System Start-up and OperationOnce the system has been installed and tested, it is ready to be powered. A manually controlledsystem will have to be turned on at each snow storm and turned off when the roof is cleared ofall snow. Thermostatically controlled systems and dual sensing systems will turn on and offautomatically.

Prior to system start-up, DO:• Perform a final visual inspection of all circuits.• Perform a final insulation resistance test of all circuits.• Instruct owner/user on system operation and maintenance.• Be sure that owner/user has all applicable installation instructions and operation manuals.

Indication of OperationSome possible indicators of a properly operating system are the following:

• The controller may indicate the circuit is powered.• Visible paths may show through the snow around the heating cable.• Cable may feel warm to the touch.• Water drainage may be visible at the gutter or downspout.

Periodic Inspection/Maintenance• Perform a visual inspection of the heating cable at least once a year to make sure physical

damage has not occurred.

• Check ground-fault device for proper operation per manufacturer’s recommendations.

• Ensure the gutters and downspouts are free of leaves and other debris prior to each winterseason.

• Test all circuits for proper insulation resistance before each winter season (see “TestMethods” on page 25).

• Make sure the control system is functioning before each winter season.

Roof/Gutter Repair and Maintenance If maintenance is needed on the roof, gutter, downspouts, or other areas close to the heatingcable, you should:

• Disconnect power to all heating cable circuits.

• Protect the heating cable from damage during repair work.

• Check for heating cable damage after any repairs or maintenance on roof or gutters. This shouldinclude a visual inspection of all heating cables and components, and insulation resistancetesting of all circuits.

• Reconnect power to all heating cable circuits.

27


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TroubleshootingSymptom Probable Causes Correction

A. Circuit breaker trips. Circuit breaker undersized. Resize the circuit breakers and feed wiring Circuit length too long. according to Table 5.1 on page 23. Start-up temperature below

design temperature.

Defective circuit breaker. Replace the circuit breaker.

Connections or splices may be To confirm that heating cable is damaged, test shorting out. the insulation resistance according to the pro-

Physical damage to the heating cable. cedure described in the “Test Methods” section(pages 25–26).

Locate and repair incorrect connections or splices.

Locate and remove damaged sections of heating cable.

To locate shorting problems, follow these steps:

1. Visually inspect the power connection, splices,and end seals for proper installation.

2. Check for visual indications of damage to thecable, especially in any area where there mayhave been maintenance work.

3. Look for damage at entrances to downspouts,around eaves, and at transitions from roof togutter.

4. If at this point you have not located theproblem, you will need to begin isolatingsections of the heating cable to find the generalarea of damage. (For example, cut the circuit inhalf and, using a megohmmeter, test bothhalves to find the damaged section.) Thenremove the damaged section of heating cable.

Bus wires in contact with each other. Cut off the end seal. Re-cut the cable end andinstall a new end seal.

Excessive moisture in connection Dry out and re-seal connections and splices. boxes or splices. Test with a megohmmeter, per installation

instructions.

Nick or cut in heating cable or power Locate and replace damaged power feed wire.feed wire with moisture present.

Using 5-mA ground-fault interrupter Replace circuit breaker with 30-mA ground-faultinstead of 30-mA ground-fault protection device. See GFEPD Selection Guideprotection device. (H55476) for information on different breakers.

B. Power output is zero or appears low. Low or no input voltage. Check voltage and correct.

Circuit is shorter than design shows Check length of cable installed. Check allbecause splices or tees are not splices and tees. Check at end seals for connected, or the heating cable continuity as indicated in the “Test Methods” has been severed. section (pages 25–26).

Improper connection causes a high- Check and fix splices or tees.resistance connection.

The control thermostat is wired Check and rewire controller. incorrectly.

28

IceStop SystemOperation and Maintenance

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29

IceStop SystemOperation and Maintenance

Symptom Probable Causes Correction

C. Heating cable fails insulation Connections or splices may be To confirm that heating cable is damaged orresistance test. shorting out. components are shorting, test the insulation

Physical damage to the heating cable. resistance according to the procedure described inthe “Test Methods” section (pages 25–26).

Locate and repair incorrect connections or splices.

Locate and remove damaged sections of heating cable.

To locate shorting problems, follow these steps:

1. Visually inspect the power connection, splices,and end seals for proper installation.

2. Check for visual indications of damage to thecable, especially in any area where there mayhave been maintenance work.

3. Look for damage at entrances to downspouts,around eaves, and at transitions from roof togutter.

4. If at this point you have not located theproblem, you will need to begin isolatingsections of the heating cable to find the generalarea of damage. (For example, cut the circuit inhalf and, using a megohmmeter, test bothhalves to find the damaged section.) Thenremove the damaged section of heating cable.

Excessive moisture in connection Dry out and re-seal connections and splices. boxes or splices. Test with a megohmmeter per installation

instructions.

Nick or cut in heating cable or power Locate and replace damaged heating cable orfeed wire with moisture present. power feed wire.

D. Snow is not melting around the Circuit breaker tripped. See Symptom A, “Circuit breaker trips.”heating cable. Controller not on or not working. Check controller.

Ambient temperature too cold.

E. Downspouts are blocked by ice. Circuit breaker tripped. See Symptom A, “Circuit breaker trips.”Controller not on or not working. Check controller.Ambient temperature too cold.

F. The circuit does not draw sufficient Circuit breaker tripped. See Symptom A, “Circuit breaker trips.”power of approximately 12 W/ft at Controller not on or not working. Check controller.32°F (0°C) in snow or ice All sections not connected. Repeat continuity test, as detailed on page 26.(5 W/ft at 32°F [0°C] in air).

00485_Raychem_6-3-99 7/19/99 12:21 PM Page 29

Appendix A. IceStop Heating Cables Data Sheet

30


Catalog number GM-1XT GM-2XTPower output (nominal) 12 W/ft (39 W/m) in ice or snow 12 W/ft (39 W/m) in ice or snow

Voltage 120 Vac 208–277 Vac

Minimum installation temperature 0°F (–18°C) 0°F (–18°C)

Minimum bend radius 5/8" (16 mm) 5/8" (16 mm)

Maximum circuit length in feet (meters) Start-up Circuit breaker sizetemperature 15 A 20 A 30 A 40 A*

GM-1XT at 120 volts 32°F (0°C) 100 (30) 135 (41) 200 (61) —20°F (–7°C) 95 (29) 125 (38) 185 (56) 200 (61)0°F (–18°C) 80 (24) 100 (30) 155 (47) 200 (61)

GM-2XT at 208 volts 32°F (0°C) 190 (58) 250 (76) 380 (116) —20°F (–7°C) 180 (55) 235 (72) 355 (108) 380 (116)0°F (–18°C) 145 (44) 195 (59) 290 (88) 380 (116)

GM-2XT at 240 volts 32°F (0°C) 200 (61) 265 (81) 400 (122) — 20°F (–7°C) 190 (58) 250 (76) 370 (113) 400 (122)0°F (–18°C) 155 (47) 205 (62) 305 (93) 400 (122)

GM-2XT at 277 volts 32°F (0°C) 215 (66) 290 (88) 415 (126) — 20°F (–7°C) 200 (61) 265 (81) 400 (122) 415 (126)0°F (–18°C) 165 (50) 225 (69) 330 (101) 415 (126)

*Only FTC-P power connection, FTC-HST splice/tee, and RayClic-E end kits may be used with 40-amp circuits.

Components IceStop heating cables must be terminated using only approved RayClic or FTC components. Refer to the Design and Installation Guidelines of this document.

Bus wire 16 AWG nickel-coated copper

Braid/outer jacket Tinned-copper braid with fluoropolymer outer jacket

Dimension Max width 0.54" (14 mm)Max thickness 0.24" (6 mm)

Nominal weight 92 lb/1000 ft (137 kg/1000 m)

Agency approvals Ordinary and hazardous locationsClass I, Div. 2, Groups A, B, C, D

The GM-1XT and GM-2XT heating cables are UL Listed, CSA Certified, and FM Approved only when used with the appropriate agency-approved Raychem components and accessories.

Ground-fault protection To minimize the danger of fire from sustained electrical arcing if the heating cable is damaged orimproperly installed, and to comply with the requirements of Raychem and the 1996 NationalElectrical Code, ground-fault protection must be used on each heating cable branch circuit. Arcingmay not be stopped by conventional circuit protection. Availability of 40-amp ground-fault circuitbreakers may be limited. See the GFEPD Selection Guide (H55476) for information on differentbreakers. Square D and Westinghouse breakers are available through Raychem.

Buswires

Conductivecore

Innerjacket

Tinned-copperbraid

Outerjacket

877Z De-icing andSnow MeltingEquipment

DESIG. 2E

00485_Raychem_6-3-99 8/11/99 10:53 AM Page 30

Appendix B. Condensed CSI Specification

ROOF AND GUTTER DE-ICING SYSTEM

PART 1 - GENERAL

Furnish and install a complete UL Listed, CSA Certified, and FM Approved system of specifiedheating cable, components, and controls listed specifically for keeping roof eaves, gutters, anddownspouts from being clogged by ice and snow.

PART 2 - PRODUCTS

Heating CableThe self-regulating heating cable shall consist of two (2) 16 AWG nickel-coated copper bus wiresembedded in a self-regulating polymer core that varies its power output to respond totemperature along its length, allowing the cable to be crossed over itself without overheating, tobe used with wood, plastic, and asphalt building materials and to be cut-to-length in the field.

The heating cable shall operate on (select 120 or 208–277) volts.

The heating cable shall be IceStop GM-1XT or GM-2XT cable manufactured by RaychemCorporation.

ComponentsAll heating cable components shall be UL Listed, CSA Certified, or FM Approved for use as partof the system to provide roof and gutter de-icing. Component enclosures shall meet NEMA 4Xrequirements to prevent water ingress and corrosion.

Attachment AccessoriesThe system will be supplied complete with attachment clips for all roof surfaces and valleys, aswell as downspout hangers.

PART 3 - PERFORMANCE

Power OutputFor sufficient power for roof and gutter de-icing and energy conservation, the self-regulatingheating cable shall have a nominal power output of 12 watts per foot in snow and ice and 5 wattsper foot in air, per IEEE 515.1-1995, Section 4.2.6. Products that do not meet this requirementare not acceptable.

Mechanical ToughnessTo provide superior abrasion resistance and mechanical impact resistance, the heating-cableouter jacket shall be an abrasion-resistant fluoropolymer. The cable shall have a minimum impactresistance of 10 ft-lb at 0°C installation temperature per IEEE 515-1997, and a crush resistanceof 2000 lb per UL1588-1993.

UV StabilityCable and components shall be qualified for prolonged exposure to the sun per IEEE 515.1-1995,Section 4.3.2, and UL1588-1993.

Submersion in WaterThe cable and components shall be qualified to withstand continuous submersion in water for2000 hours per IEEE 515.1-1995, Section 4.3.1.

PART 4 - CONTROL

OPTION 1: AUTOMATIC SNOW CONTROLLERThe system shall be controlled by one or more GIT-1 gutter-mounted sensors along with aCIT aerial-mounted sensor in combination with an APS control panel through an appropriatecontactor.

OPTION 2: THERMOSTATThe system shall be controlled by an ambient sensing thermostat (AMC-F5 or AMC-1A) eitherdirectly or through an appropriate contactor.

OPTION 3: MANUAL SWITCHThe system shall be controlled by a manual switch either directly or through an appropriatecontactor.

31


00485_Raychem_6-3-99 8/11/99 10:53 AM Page 31

PART 5 - ELECTRICAL

ContactorThe contactor shall be a three-pole contactor with a rating of 40 or 100 amps per pole in aNEMA-4X enclosure.

Ground-Fault Circuit BreakerPer the National Electrical Code, Article 426, the system shall be protected by a 30-mA-trip ground-fault circuit breaker.

PART 6 - SYSTEM WARRANTY

The system will have a complete 10-year warranty.

PART 7 - EXECUTION

Installation

• The heating cable shall be laid in gutters; shall be suspended in downspouts either as a loop ora single length and held in place by a downspout hanger; and shall be attached to the roofusing the appropriate roof clip.

• The heating cable shall be protected from damage and installed according to manufacturer’sinstructions.

TestsAfter installation, the dielectric jacket’s insulation resistance and continuity shall be tested with a2500 Vdc megohmmeter. Insulation resistance from the conductors to the shield shall be greaterthan 1000 megohms.

32

CondensedCSI Specification

00485_Raychem_6-3-99 8/11/99 10:53 AM Page 32

Appendix C. IceStop System Warranty

Seller warrants heating cable and heating cable connectors and terminations delivered hereunderagainst faulty workmanship and use of defective materials for a period of 10 years from the date ofshipment. When the contract calls for systems design, drawings, technical advice, services, orinstructions (collectively “Services”) by Seller, whether or not in connection with the products,Seller further represents for the above stated warranty period solely that such Services will beundertaken in accordance with Seller’s reasonable technical judgement based on Seller’sunderstanding of the pertinent technical data as of the date of performance of such Services, andthat any such Service will meet in all material respects any technical specifications provided for inthe contract. SUCH WARRANTY IS THE ONLY WARRANTY MADE BY SELLER AND CAN BEAMENDED ONLY BY WRITTEN INSTRUMENT SIGNED BY A DULY AUTHORIZED OFFICER OFSELLER. If the products furnished by Seller hereunder are determined to contain a deficiency,Buyer’s exclusive remedy shall be to have Seller repair such products or supply replacementproducts or credit Buyer’s account for such products and accept their return, whichever Sellermay elect in its sole discretion. Notwithstanding the foregoing sentence, in no circumstancesshall Seller have any liability or obligation with respect to expenses, liabilities, or losses associatedwith the installation or removal of any products or the installation of replacement products or forany inspection, testing, or redesign occasioned by any deficiency or by the repair or replacementof products. Seller’s obligations are subject to further condition that Seller shall have no liabilitywhatsoever for any deficiency unless (I) Seller is notified in writing promptly (and in no eventlater than 30 days) after discovery by Buyer of the alleged deficiency, which notice shall include adetailed explanation of the alleged deficiency, (II) the products containing the alleged deficiencyare promptly returned to Seller, F.0.B. Seller’s plant, and (III) Seller’s examination of suchproducts discloses to Seller’s satisfaction that such alleged deficiency actually exists and occurredin the course of proper and normal use and was not caused by accident, misuse, neglect, alteration,or improper installation, repair, or testing. If any products so prove to contain a deficiency andSeller elects to repair or replace them, Seller shall have a reasonable time to make such repairsor replacement. THE FOREGOING WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSOR IMPLIED, INCLUDING WITHOUT LIMITATION ANY IMPLIED WARRANTY OF MERCHANTABILITY,FITNESS FOR A PARTICULAR PURPOSE, OR NONINFRINGEMENT, AND OF ANY OTHER OBLIGATIONON THE PART OF SELLER.

33


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34


00485_Raychem_6-3-99 8/11/99 10:53 AM Page 34

Design Worksheet

35

This design worksheet is meant to provide a quick way to estimate the products needed for a roof and gutter de-icing application on standardroofs. You only need to use the sections necessary for your roof application. Refer to the body of this guide for complete information.

1. Determine heating cable design and amount of heating cable required for your roof application.A. Sloped roof—nonstanding seam

(page 4)

B. Sloped roof—standing seam(page 5)

C. Valleys(page 8)

D. Roof /wall intersections(page 8)

E. Flat roof (page 6)

F. Gutters and downspouts —nonstanding-seam roof (pages 9–10)

G. Wide gutters(page 9)

H. Heated drip edge (page 16)

I. Drip loops No additional heating cable required

J. Downspouts—standing-seam roof with gutters (page 9)

Add together amount of heating cable needed.

2. Select heating cable. Voltage: ❏ 120 Vac (GM-1XT) ❏ 208–277 Vac (GM-2XT)

3. Determine number of circuits.30-mA ground-fault circuit breaker size available (check one): ❏ 15 A ❏ 20 A ❏ 30 A ❏ 40 A**Only FTC-P power connection, FTC-HST splice/tee, and RayClic-E end kits may be used with 40-amp circuits.

Using Table 5.1 on page 23, determine the maximum circuit length allowed:

Total heating cable length divided by maximum circuit length allowed equals minimum number of circuits required

4. Select components. Determine quantity of components and heating cable allowance (from Table 4.3 on page 22).

A. Power connection

B. Tee connection

C. End seals (included in powerconnection kits and tee kits)

# of tee kits3 ft

Heating cablecomponent allowance

# of tee kits# of tees

# of powerconnection kits

2 ftHeating cable

component allowance

# of circuits # of powerconnection kits

Heating cablelength

# of circuitsrequired

Max. circuitlength

Feet max.

Height ofdownspout

Number ofdownspouts

Runs of heatingcable per

downspout

Feet of heatingcable per

downspout

Length ofroof edge

Feet of heatingcable for heated

drip edge

2Length ofgutters

Height ofdownspout

Number ofdownspouts


downspout

Feet of heatingcable for gutters

Length ofgutters

Height ofdownspout

Number ofdownspouts


downspout

Feet of heatingcable for gutters

Feet of roofperimeter

Footageto drains

Footagein drains

Feet of heatingcable for flat roof

Height ofintersection

1.33Feet of heating

cable forintersection

Heightof valley

1.33Feet of heatingcable for valley

Feet of heatingcable per footof roof edge

Feet ofroof edge

Feet of heatingcable for roof

Feet of heatingcable per footof roof edge

Feet ofroof edge

Feet of heatingcable for roof


00485_Raychem_6-3-99 7/19/99 12:22 PM Page 35

36

IceStop SystemDesign Worksheet

5. Determine total heating cable length required.A. Heating cable length (from Step 1)

B. Component heating cable allowances (Step 4)

C. Amount of extra heating cable needed

D. Add A + B + C to get total amount of heating cable needed. Recheck number of circuits (Step 3).

6. Select attachment accessories. Select the attachment method from Table 2.1 on page 11.Determine the minimum quantity of attachment accessories required.

A. Sloped shake or shingle roof

B. Other sloped nonstanding-seam roof

C. Standing-seam metal roof

D. Flat roof

E. Gutter (up to 6" wide): None required

F. Wide gutter (6"–12" wide):

G. Downspouts

7. Select control method. Select the method of control from Step 3, pages 18–20:

A. Automatic moisture/temperature controller

or

B. Ambient thermostat ❏ AMC-F5 ❏ AMC-1A

or

C. Manual control

8. Fill in Bill of Materials.

Quantity Units Catalog # Description

feet GM-____XT Heating cable

each Ground-fault protection devices

each Power connection kits

each Splice kits

each Tee kits

each GMK-RC Roof clips

each GM-RAKE Downspout hangers

each Cable ties

each AMC-____ Ambient sensing thermostat

each CIT Aerial-mounted moisture/temperature sensor

each GIT Gutter-mounted moisture/temperature sensor

each APS ____ APS controller

# of runsof gutter

# of GITsensors

One CIT sensorper APS panel

APS panels (upto 6 sensorsper panel)

# of downspouts # of runs of heatingcable per downspout

# of GM-RAKEdownspout hangers

250Roof length

in feet# of boxes of

50 GMK-RC clips

5Heating cable

length# of GMK-RC clips

or “belt loops”

Seam spacingin feet

2# of GMK-RC clipsRoof length

in feet

# of seamstraced

4# of GMK-RC clips

or other clips

Roof lengthin feet

# of boxes of50 GMK-RC clips

35

00485_Raychem_6-3-99 7/19/99 12:22 PM Page 36

Raychem Corporation 300 Constitution DriveMenlo Park, California 94025-1164USATel (800) 545-6258Fax (800) 611-2323Fax-on-Demand (800) [email protected]

Raychem Canada LimitedToronto, OntarioCanadaTel (800) 545-6258Fax (650) 361-5579

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Important: All information, including illustrations, is believed to be reliable. Users, however, shouldindependently evaluate the suitability of each product for their application. Raychem makes no warranties as tothe accuracy or completeness of the information, and disclaims any liability regarding its use. Raychem’s onlyobligations are those in the Raychem Standard Terms and Conditions of Sale for this product, and in no casewill Raychem or its distributors be liable for any incidental, indirect, or consequential damages arising from thesale, resale, use, or misuse of the product. Specifications are subject to change without notice. In addition,Raychem reserves the right to make changes—without notification to Buyer—to processing or materials thatdo not affect compliance with any applicable specification.

ElectroMelt, HWAT-Plus, IceStop, RayClic, RaySol, and XL-Trace are trademarks of Raychem Corporation. 9 0 01ISO

BR3554.FNT 7/19/99 12:25 PM Page 1

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