●How is your resistancewire sized?

●What grade ofmagnesium oxide isbeing used?

●How is your cold pinattached to yourresistance wire?

●What is your standardelement diameter?

●Do you passivatestainless steel heaters?

●Do you repress U-bendswhen required?

●Do you use terminalsealant as a standard?

●How are your elementsfixed to the screw plug?

●Are screw plug hex andthreads to industrystandards?

●Do you provide a standardthermowell?

●Is the terminal housingrotatable?

●Do you have a standardgrounding lug?

●Are your heaters UL listedand CSA certified?

●What quality assurancetesting is done on yourfinished products?

●Can you ship out ofstock in 24 hours andprovide assembly stockproducts in 5 days?

●Can you provide me experttechnical assistance whenneeded?

PDS QUALITY

www.chromalox.com ©1998 Wiegand Industrial Division

8

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1 9

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16

On first impression, various manufacturers of screw plug immersionheaters appear to be all alike; but when you take a closer look at screw plugimmersion heaters, it becomes evident that considerable differences exist.The following information will help to explain the differences in constructionof Chromalox screw plug immersion heaters compared to other manufacturers.It will also describe Chromalox’s third party listing program, quality testing,and delivery capabilities.

Before buying a screw plug heater, you should ask the manufacturerquestions to insure you are getting a quality heater that will last in yourapplication. Below, you will find a list of some of these important questions.

Screw Plug Immersion Heatersinclude one, two or three hair-pin bent tubular element(s)joined to a threaded hex plug.Screwed into tank walls,this UL Listed / CSA Certifieddirect contact heat source heatsliquids, viscous fluids, forced airand gases with maximumenergy efficiency. In addition,elements can be bent into manyconfigurations to suit a varietyof applications. Most screw plugheaters come with a thermowell(for temperature control sensor)and a completely wired terminalenclosure for electrical connec-tion. Certain models availablewith a patented 360° rotatablescrew plug housing to facilitateeasy conduit connections. Selectfrom a variety of sheath materi-als, element lengths, plug sizesand ratings from 0.5 kW and up,for 120 to 600 volts.

DifferencesAmong

Screw PlugImmersion

Heaters

http://www.chromalox.com

Basic Construction

Element Diameter

Stainless Steel HeatingElement Surface Finish

Chromalox® standard 0.475” Diameter

10% more surface area than0.430” diameter typical of competitors

Results in longer life and loweroperating temperature

0.475”

Pickling & PassivationRemoves most carbon particles

���������

Elements

Thermowell

Rotatable TerminalHousing

Hex Threads

Resistance Wire-Computer Designed for correct gauge wire

MetallicSheath

CompactedMagnesium OxideInsulation

Solid ColdPin Junction

Hex

Elements InternalConstruction

Quality - Differences Among Screw Plug Immersion Heaters

Chromalox connects the resistance wire to the cold pin with a weld. This provides asolid electrical connection that better withstands thermal cycling. Some manufac-turers press or braze the cold pin onto the resistance wire, making failure due tothermal cycling more common. Ask the heater manufacturer how they maketheir cold pin connections. Chromalox uses only high purity magnesium oxideinsulation to insure good dielectric resistance between the resistance wire and themetal sheath. In addition, Chromalox uses a rolling method to reduce the diameterand compact the MgO refractory. Other manufacturers often use lower grades ofMgO, and swage versus rolling down the element diameters, causing inferiordielectric properties which can lead to a less reliable heater. By utilizing highgrade materials and having controlled manufacturing processes, good thermalconductivity is achieved and a longer life heating element is produced. Ask theheater manufacturer how they compact element refractory.

Chromalox® www.chromalox.com

Corrosion is often accelerated by a poor surface finish. Proper surface finish ofstainless steel heating elements is very important to prevent corrosion. Duringtypical heater manufacturing processes, steel dies and rollers come intocontact with the element sheath, and as a result, carbon steel particles areembedded into the surface of the element. If not removed, pitting and corro-sion will occur, eventually leading to premature heater failure. As standardpractice, Chromalox pickles and passivates stainless steel heaters by soakingthe elements in an acid bath. This process removes the carbon steel particlesfrom the surface of the heating element and prolongs heater life. Othermanufacturers will only passivate for an extra charge. Ask the heatermanufacturer if passivation is a standard practice.

Although Chromalox makes elements that range from 0.315” to 0.475” indiameter, our standard 2” and 2-1/2” NPT screw plug immersion heaterelements are 0.475” in diameter. Other manufacturers have standardized on0.430” diameter elements to reduce costs. For an equivalent immersion length,the 0.475” diameter heating element provides 10% more surface area versus a0.430” diameter element. The greater the surface area, the lower the heaterwatt density and lower its operating temperature. Lower operating tempera-tures result in longer heater life. Ask the heater manufacturer whatdiameter elements they supply as standard.

The basic construction of an immersion heater includes the terminal housing,standard NPT screw plug, thermowell and heating elements. If you take acloser look at the construction of a heating element, you will find the heart ofthe heater is the resistance wire. Chromalox’s resistance wire is computerdesigned in order to select the correct gauge wire for the required heatingelement wattage and voltage. Many manufacturers use limited sizes of wire,and may not choose the optimal wire for the application. Ask the heatermanufacturer how they determine resistance wire dimensions.

http://www.chromalox.com

Welded Stainless/Steel Elements

Terminal Seal Types

Elements U-Bends

Air gapsin Mgo

Electricalshortto sheath

RecompactsMgo

Removesanyair gaps

Silicone - Fluid, Resin, RTV200°F to 300°F continuous exposureModerate moisture barrier

Epoxy200°F continuous exposureGood moisture barrier

HermeticUp to1000°F sheath temperatureThe only true seal

Minimizes corrosionat element attachment

Solder not a goodcorrosion resistant material

Prevents leakageinto terminal enclosure

Elements U-Bends -Repressed

Quality - Differences Among Screw Plug Immersion Heaters

Most screw plug immersion heater elements are bent in a U-bend configura-tion. When bending a heating element on a tight radius, air gaps can occur inthe magnesium oxide insulation within the element bend. Air gaps can permit adielectric (insulation) breakdown to occur, and cause an electrical short to themetal sheath of the heater.Chromalox represses U-bends to recompact the MgO and remove any air gaps,which ensures dielectric integrity. Many manufacturers do not repress bends tosave time and money. Ask the heater manufacturer if they repressU-bends when necessary.

Heating element refractory can absorb moisture from the air, and if enoughmoisture is absorbed, high leakage current could occur during start-up.Chromalox screw plug immersion heaters contain heating element terminalsealant as a standard feature. A terminal sealant inhibits moisture from beingabsorbed by the heating element refractory.There are several optional types of terminal sealants to suit the particularapplication. Ask the heater manufacturer about terminal sealants beforemaking a purchase decision.

Chromalox stainless steel, INCOLOY® and carbon steel elements are welded tostainless and carbon steel screw plugs. A welded element provides superiorcorrosion protection and element attachment. Some manufacturers brazeelements to the screw plug without concern for the heaters intended applica-tion. In heating a corrosive fluid, braze material is susceptible to being chemi-cally attacked by the fluid. A welded-in element prevents corrosive fluidleakage into the terminal housing which can lead to heater failure. Ask theheater manufacturer how they secure their elements to the screw plug.

Chromalox® www.chromalox.com

http://www.chromalox.com

Thermowells

Hex and Threads

Hex and Threads -Other Supplier Alternatives

Wide hex fitsstandard tools

Long threadsfortighter fit

Easy to install

Standard to acceptsensing bulbs

Integral and remotethermostat options

IT DOESTHETWIST

Unique with360 DegreeRotation Feature

Rotatable TerminalHousing

Differences Among Screw Plug Immersion Heaters - Quality

Short hex requiresspecial tools

Short threadssusceptible todamage

Short threadscause loose fitinto tank

Difficult to install

Chromalox®

www.chromalox.com

Chromalox heater design provides a screw plug hex and threads that are userfriendly. Wide hex and generous threaded lengths allow standard tools to beused and allows a secure fit.Other manufacturers often provide a narrow hex, making the hex difficult togrip, potentially damaging the screw plug threads, or short thread lengths thatmay not provide a tight seal. Chromalox screw plug immersion heaters are easyto install — no special tools are required. Ask the heater manufacturer iftheir Hex and Threads meet industry standards.Chromalox stainless steel and steel screw plugs come with a standard solid hexand threads. Others use stamped, cast or hollow plugs and threads that can failunder higher pressures.

The NEMA 1 terminal enclosure of the Chromalox screw plug heater is fullyrotatable. This patented feature allows 360° rotation of the terminal enclosure(270° rotation for heaters with thermostat). Thus, you are able to rotate theenclosure (housing) to face the electrical conduit connection after the heaterhas been properly installed.During installation, it is preferred that the conduit for the wiring be in a downposition. This prevents any moisture that may accumulate on the conduit fromrunning down into the terminal enclosure of the heater and cause potentialheater failure. No other heater manufacturer offers this feature.

Chromalox screw plug immersion heaters can be provided with or without anintegral thermostat. Regardless, a thermowell is standard on most heaters toaccept the sensing bulb of a thermostat. This allows an easy retrofit if later youlearn that a thermostat is necessary. Most manufacturers charge extra forthermowells. Ask the heater manufacturer if a thermowell is standard.

http://www.chromalox.com

Differences Among Screw Plug Immersion Heaters - Quality

Electrical Grounding

Third Party Listing

Quality Testing

Most Extensivein the Industry

UnderwritersListing (UL)

Canadian StandardsAssociation (CSA)

NationalElectrical CodeRequirement

ChromaloxStandard

Ground lugsnot providedby all suppliers

100% HydrostaticPressure Test forWeld Leaks

100% Resistance Checkfor Element Wattage

Insulation ResistanceCheck for Moisture20 Megohms or greater

Dielectric Hi-pot Check

UL®

Chromalox’s stocking program is unequaled in the industry. Our distributionwarehouse can ship stock heaters within 24 hours of receipt of an order.Chromalox has over 1,000 different screw plug heaters in stock. In addition,most of our assembly stock products can ship within 5 days. And, we offer 10day shipment for many of our other thousands of pre-engineered designs. Wealso provide a toll free service number for replacement part orders and installa-tion assistance. 1-800-368-2493. Ask the heater manufacturer abouttheir delivery times and stock offering.

Delivery and ServiceStock heaters shipped in 24 Hours

Over 1000 Screw Plug heaters in stock

Chromalox® www.chromalox.com

Proper electrical grounding is extremely important and is required by theNational Electrical Code. Some manufacturers do not provide a standardgrounding lug with their heaters. Grounding lugs are a standard feature withChromalox heaters. Ask the heater manufacturer if a grounding lug isstandard.

Chromalox heaters undergo extensive quality inspection prior to shipment. Allscrew plug heaters are 100 percent hydrostatically pressure tested to insure atight leak-proof fit of the elements to the screw plug. We also perform a 100percent resistance check on all our heater elements to ensure proper heatingelement wattage. A two-step insulation resistance check is also performed.First, elements must have a test measurement of insulation resistance to insureminimal moisture content of the element refractory. Then, a dielectric highpotential check insures that no electrical short exists from the resistance wireto the metal sheath. Many manufacturers do not perform all of this qualityassurance testing. Ask the heater manufacturer about their testingprogram.

Chromalox has the most extensive third party listing in the industry. We providemore heaters with Underwriters Laboratory listing and/or Canadian StandardsAssociation Certification than all other heater manufacturers combined.This assures the heater is built to stringent standards and allows you to receivequick electrical inspector approval. Ask the heater manufacturer about ULListing and CSA Certification.

http://www.chromalox.com

PD315-1PDS QUALITY

OCT 9899-006

In SummaryOver 80 years of experience

Highest quality heaterconstruction

Extensive UL/CSAListings/Certifications

Comprehensive testingprior to delivery

Fast delivery andcustomer service

Chromalox has over 80 years of experience, the highest quality construction,extensive UL Listings and CSA Certifications, a comprehensive quality programand the largest stock and pre-engineered designs of any manufacturer.Chromalox also has the largest and most technically competent field salesforce in the industry. This means you get the best products and applicationsupport when you need it!To Chromalox, an educated customer is our best customer. We are proud tobuild the world’s highest quality and longest lasting screw plug heaters. Weask you to ask these questions to whomever you buy your screw plug heatersfrom. Remember, not all screw plug heaters are created equal.

Benefit

♦ Longer Lasting, More Reliable Heater

♦ Higher Consistency and Quality

♦ Longer Lasting Heaters

♦ Higher Dielectric Integrity

♦ Insulation Moisture Inhibitor

♦ Resists Chemical Attack

♦ Easier Installation, Better Fit

♦ Insures NEC Compliance for Ground

♦ Proper Enclosure Orientation Makes for Easy Installation

♦ Insures Highest Quality and Strict Manufacturing

Procedures

♦ Greater Reliability

♦ Large Stock & Assembly Stock Offering

♦ Lower Lead Times for Assembly Stock and Special Order Products

♦ Support and Assistance When You Need It Most

Feature / Benefit Analysis

Quality - Differences Among Screw Plug Immersion Heaters

Chromalox® www.chromalox.com

Feature

♦ High Quality Components

♦ Strict Manufacturing Processes

♦ Element Diameter as required

♦ Repressed Bends where necessary

♦ Standard Terminal Sealant

♦ Welded Elements

♦ Standard Hex Width and Thread Length

♦ Standard Grounding Lug

♦ Rotatable Enclosure

♦ Third Party Listing (for a list, ask your Representativefor bulletin PD314)

♦ Comprehensive Quality Assurance Testing

♦ Product Availability

♦ Responsive Production Facilitye

♦ Highly Technical and Experienced Sales Force

http://www.chromalox.com

1.000+.031-.062

REF HEX.1.500

.437 REF

.875 REF (TYP)

.248+.000-.187

"C"±.750

"B"±.125

1.000+.031-.062 .328

.187 REF (TYP)

REVISION

S

REV.D

ESCRIPTION

DA

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APVD

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12RED

RAW

N IN

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RMA

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TTAG

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CE WA

S ±5%

ECR-10993-20-06

RKCRB

13D

IMEN

SION

"C" CHA

NG

E FROM

2.125" TO 4.187". ECR 2149

11-19-08PM

OCVM

14D

IMEN

SION

"C" OF 2.125" W

AS 4.187 EXCEPT FO

R ITEMS

-075,-098,-099,-103,-107,-114,-115,-120. ECR 2219 2-26-09

PMO

FMS

15

W/

" ON

ITEM -075 W

AS 132; W

/" O

N ITEM

-098 WA

S 206;W

/" O

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-099 WA

S 206; W/

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ITEM -103 W

AS 132;

W/

" ON

ITEM -107 W

AS 204; W

/" O

N ITEM

-114 WA

S 198;W

/" O

N ITEM

-115 WA

S 198; W/

" ON

ITEM -120 W

AS 142.

DIM

. "C" ON

ITEM -099 W

AS 2.125. ECR 2337.

6-23-09RER

FMS

RY

1 Of 2

Critical to Regulatory Requirements

(x.xx=Cpk requirem

ents) Critical to Q

uality (x.xx=

Cpk requirements)

Angles: ±

2°W

attage: +5-10%

Sheet:

15156-563153-000

CU

nless otherwise specified, all

dimensions are in inches. M

etricequivalent show

n in [ ].

M

etric±

0.80±

0.25±

0.13

English±

.030±

.010±

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x.xx.xxx.xxx

Revision:D

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IMM

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TER SCREW PLU

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Third Angle Projection: U

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NSI Y14.5-1994 to interpret

drawing. D

o not scale drawing.

Title:G

eneral Tolerances:

Emerson H

eating Products

9-10-96S.SPRIN

GER

DW

O-054585, 156-048666-000

Date:

Approved by:

Reference:

6-16-88RM

D

ate:Checked by:

9-25-97RKC

Date:

Draw

n by:M

aterial:

PART NUMBER CATALOG NUMBER VOLTS WATTS "B" "C" FIGURE W/ " PCN NUMBER REMARKS

156-563153-

120208240277480

600600600600600

-006

-008

SG-1077

120208240277480

750750750750750

7.750 2.125 I 70

459575

459567

-011

-013

SG-1107

120208240277480

10001000100010001000

7.750 2.125 I 94

457406

459161

-016

-018

SG-1103

120208240277480

10001000100010001000

7.750 2.125 I 94

458118

458100

-021

-023

SG-1127

120208240277480

12501250125012501250

7.750 2.125 I 117

459129

457385

-027 -028

SG-1123

120208240277480

12501250125012501250

7.750 2.125 I 117

459401455363

-031

-033

SG-1157

120208240277480

15001500150015001500

7.750 2.125 I 141

459073

452613

-036 -037 -038

SG-1153

120208240277480

15001500150015001500

7.750 2.125 I 141

455347459268455355

-041

-043

SG-1207

120208240277480

20002000200020002000

10.687 2.125 I 129

455056

452621

-046 -047 -048

SG-1203

120208240277480

20002000200020002000

7.750 2.125 I 187

455400459410455339

-053

SG-2257

120208240277480

25002500250025002500

7.437 2.125 II 133

452630

-056 -057 -058

SG-1253

120208240277480

25002500250025002500

9.500 2.125 I 185

457414459428455320

-062 -063

SG-1303

120208240277480

30003000300030003000

10.687 2.125 I 194

459436452867

-066 -067

SG-1353

208240277480

3500350035003500

12.687 2.125 I 187

459444455312

-071

SG-2357

208240277480

3500350035003500

9.937 2.125 II 130

452656

NOTES: STAMP BLOCK WITH: CATALOG NUMBER, VOLTS, WATTS, DATE CODE, MANUFACTURERS LOCATION CODE AND CUSTOMER PART NUMBER WHEN SPECIFIED. 120V ELEMENTS REQUIRE "L" SUFFIX IN CATALOG DESCRIPTION, EXAMPLE: (SG-1077L) GASKET- BULK PACK (50 PCS). ALL POLY TERMINAL BLOCKS ARE TO BE BLACK WITH WHITE OR GOLD STAMP UNLESS OTHERWISE SPECIFIED. CSA MONOGRAM REQUIRED ON ELEMENTS WITH A VOLTAGE RATING OF 480V AND BELOW AND WATTAGE RATING OF 6000W AND BELOW. PLATED STEEL SCREW PLUG 1"-11 1/2 NPSM. .260 DIA. PLATED COPPER SHEATH. FOR ADDITIONAL SPECIFICATION ON REPRESS, PIN CUT, TERMINAL BLOCK HEIGHT REQUIREMENTS AND Q.A. INSPECTION REQUIREMENTS SEE DRAWING 156-895669-000 FOR HAIR PIN DESIGN (FIG 1) OR 156-895670-000 FOR FOLDBACK DESIGN (FIG II).

FIG I FIG II

#10 PHILLIPS PAN HEADTERMINAL SCREW

+.000-.187

1

2

3

4

5

6

7

8

3

7

6

1 2 4 5

REF HEX.1.500

"B"±.312

.437 REF

1.000+.031-.062

.328

"C"±.750

"B"±.125

.248+.000-.187

.875 REF (TYP)

.187 REF (TYP)

REVISION

S

REV.D

ESCRIPTION

DA

TEBY

APVD

.

12RED

RAW

N IN

TO Pro/E FO

RMA

T, REMO

VE NO

TE 9, REVISE WA

TTAG

ETO

LERAN

CE WA

S ±5%

ECR-10993-21-06

RKCRB

13D

IMEN

SION

"C" CHA

NG

E FROM

2.125" TO 4.187". ECR 2149

11-19-08PM

OCVM

14D

IMEN

SION

"C" OF 2.125" W

AS 4.187 EXCEPT FO

R ITEMS

-075,-098,-099,-103,-107,-114,-115,-120. ECR 2219 2-26-09

PMO

FMS

15

W/

" ON

ITEM -075 W

AS 132; W

/" O

N ITEM

-098 WA

S 206;W

/" O

N ITEM

-099 WA

S 206; W/

" ON

ITEM -103 W

AS 132;

W/

" ON

ITEM -107 W

AS 204; W

/" O

N ITEM

-114 WA

S 198;W

/" O

N ITEM

-115 WA

S 198; W/

" ON

ITEM -120 W

AS 142.

DIM

. "C" ON

ITEM -099 W

AS 2.125. ECR 2337.

6-23-09RER

FMS

RY

2 Of 2

Critical to Regulatory Requirements

(x.xx=Cpk requirem

ents) Critical to Q

uality (x.xx=

Cpk requirements)

Angles: ±

2°W

attage: +5-10%

Sheet:

15156-563153-000

CU

nless otherwise specified, all

dimensions are in inches. M

etricequivalent show

n in [ ].

M

etric±

0.80±

0.25±

0.13

English±

.030±

.010±

.005

x.xx.xxx.xxx

Revision:D

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IMM

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TER SCREW PLU

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ER: (APPLIA

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Third Angle Projection: U

seA

NSI Y14.5-1994 to interpret

drawing. D

o not scale drawing.

Title:G

eneral Tolerances:

Emerson H

eating Products

12.20-94L.KEEFO

VER}D

WO

-054585, 156-048666-000D

ate:A

pproved by:Reference:

12-15-94A

DA

Date:

Checked by:

1-5-92RKC

Date:

Draw

n by:M

aterial:

PART NUMBER CATALOG NUMBER VOLTS WATTS "B" "C" FIGURE W/ " PCN NUMBER REMARKS

156-563153- -075

SG-2407

208240277480

4000400040004000

11.750

2.1254.1872.1252.125

II

132135132132

452664

-078 -079

SG-1403

208240277480

4000400040004000

13.687 2.125 I 196

459452455380

-083

SG-2457

208240277480

4500450045004500

11.750 2.125 II 137

452672

-086 -087

SG-1453

208240277480

4500450045004500

13.687 2.125 I 221

459460452859

-091

SG-2453

208240277480

4500450045004500

7.937 2.125 II 221

459225

-095

SG-2507

208240277480

5000500050005000

13.437 2.125 II 130

452681

-098 -099

SG-2503

208240277480

5000500050005000

9.937

4.1874.1872.1252.125

II

212212206206

459284455398

-103

SG-2557

208240277480

5500550055005500

15.125

2.1254.1872.1252.125

II

132136132132

459170

-106 -107

SG-2553

208240277480

5500550055005500

9.937

2.1254.1872.1252.125

II

204233204204

457502

-111

SG-2607

208240277480

6000600060006000

15.125 2.125 II 137

452760

-114 -115

SG-2603

208240277480

6000600060006000

11.750

4.1874.1872.1252.125

II

203203198198

459250455371

-120

SG-2307

120208240277480

30003000300030003000

9.000

2.1252.1254.1872.1252.125

II

142142146142142

452648

-123

SG-1173

120208240277480

17501750175017501750

7.750 2.125 I 164

412072

-128

SG-1163L

120208240277480

16501650165016501650

7.750 2.125 I 156

459237

-135

SG-1383

120208240277480

38003800380038003800

13.687 2.125 I 187

459230

NOTES: STAMP BLOCK WITH: CATALOG NUMBER, VOLTS, WATTS, DATE CODE, MANUFACTURERS LOCATION CODE AND CUSTOMER PART NUMBER WHEN SPECIFIED. 120V ELEMENTS REQUIRE "L" SUFFIX IN CATALOG DESCRIPTION, EXAMPLE: (SG-1077L) GASKET- BULK PACK (50 PCS). ALL POLY TERMINAL BLOCKS ARE TO BE BLACK WITH WHITE OR GOLD STAMP UNLESS OTHERWISE SPECIFIED. CSA MONOGRAM REQUIRED ON ELEMENTS WITH A VOLTAGE RATING OF 480V AND BELOW AND WATTAGE RATING OF 6000W AND BELOW. PLATED STEEL SCREW PLUG 1"-11 1/2 NPSM. .260 DIA. PLATED COPPER SHEATH. FOR ADDITIONAL SPECIFICATION ON REPRESS, PIN CUT, TERMINAL BLOCK HEIGHT REQUIREMENTS AND Q.A. INSPECTION REQUIREMENTS SEE DRAWING 156-895669-000 FOR HAIR PIN DESIGN (FIG 1) OR 156-895670-000 FOR FOLDBACK DESIGN (FIG II).

+.000.-187

FIG IIFIG I

#10 PHILLIPS PAN HEADTERMINAL SCREW

1

2

3

4

5

6

7

8

3

6

7

1 2 4 5