Safe and Effective Deployment of Power over

Ethernet Todd Harpel, RCDD

Why Power over Ethernet?

• Ethernet enabling the “Internet of Everything”

• Cheaper than two circuits to a device • RJ45 connector compatibility

– The “universal” communication and now power interface

• Economical, easier power backup

Power over Ethernet Evolution

• Power over Ethernet (PoE) is over 10 years old!

• 802.3af completed in 2003 – 15W power sent = 12.95W of delivered power (Type 1) – Compatible with Cat 5e cabling and above

• 802.3at PoE+ completed in 2009 – 30W power sent = 25.5W of delivered power (Type 2) – Also compatible with Cat 5e

But we need more Power!

Source: IEEE 802.3; Four Pair Power over Ethernet; Call for Interest March 2013

Addressing the need for more Power

• Cisco – Universal Power over Ethernet (UPoE) – Proprietary 60W delivery

• Outdoor IP surveillance cameras with PTZ, heater – Draw as much as 60W to 75W

• Other switch manufacturers supporting “Non-Standard” PoE power to 60W+

• HDBaseT – HDMI extenders – Sends up to 100W

New IEEE 802.3bt PoE Standard • 4 pair power delivery to increase system efficiencies

– Higher complexity • Targeting two power variants

– Type 3 ≈ 60W – Type 4 ≈ 100W

• Support for 10GBASE-T – 802.11ac Wireless Access Point bandwidth

• Will need to account for 2.5 and 5GBASE-T • Backward Compatibility with Type 1 and Type 2 power levels • Support for operation over Cat 5e through Cat 6a cabling

Next Generation PoE Challenges

More power increases heat generation • TIA examining installed cabling issues

– TSB 184-A under development

• National Fire Protection Agency (NFPA) and the NEC – safety concerns related to bunching or bundling of

cables in raceways or pathways when delivering higher power

TIA TSB-184A

• Extensive testing and modeling of heat rise for Cat 5e through Cat 6a cables

• Target temperature rise of 15°C – Assumes “worst case” installation conditions of 45°C

(113°F) – Cable listing temperature of 60°C (140°F)

• Temperature increase levels are dependent on pathway, cable type and fill ratio

8

Heat Rise Modeling Bundles in Tray

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

0 50 100 150 200 250 300

Tem

pera

ture

Ris

e (°

C)

Center of Bundle Temperature Rise vs. Cable Count at 100W

Cat 5e UTP Predicted TempNumber of Cables

Heat Rise Modeling Bundles in Tray

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

0 50 100 150 200 250 300

Tem

pera

ture

Ris

e (°

C)

Center of Bundle Temperature Rise vs. Cable Count at 100W

Cat 5e UTP Predicted Temp

Number of Cables

TIA Target

Heat Rise Modeling Bundles in Tray

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

0 50 100 150 200 250 300

Tem

pera

ture

Ris

e (°

C)

Center of Bundle Temperature Rise vs. Cable Count at 100W

Cat 5e UTP Predicted Temp Cat 6 UTP Predicted Temp

Number of Cables

TIA Target

Heat Rise Modeling Bundles in Tray

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

0 50 100 150 200 250 300

Tem

pera

ture

Ris

e (°

C)

Center of Bundle Temperature Rise vs. Cable Count at 100W

Cat 5e UTP Predicted Temp Cat 6 UTP Predicted Temp Cat 6a UTP Predicted Temp

TIA Target

Number of Cables

Hi-Power PoE Bundle Testing

37 cable bundle testing with 100w per cable All cable types were within the TIA/IEEE

recommended temp rise

13

Worst Case Temperature Rise (°C) at 1000 mA for Bundles of 37 Cable bundle

Cable Type Temp Rise (°C)

Category 5e UTP 7.9

Category 6 UTP 6.9

Category 6A UTP 6.9

Hi-Power PoE Testing 259 cable bundle testing with 100W per cable

Temperature rise is much more pronounced

14

Worst Case Temperature Rise (°C) at 100W for Bundle of 259 Cables

Cable Type Temp Rise (°C)

Category 5e UTP 37.3

Category 6 UTP 27.2

Category 6A UTP 29.8

TIA TSB 184-A Maximum Bundle Size

• For maximum 15°C temperature rise in open tray

* Draft TIA Category 8 Cable Performance

Cable Type Maximum Bundle Size @ 100W

Category 5e UTP 56

Category 6 UTP 92

Category 6a UTP 93

Category 8* S/FTP 257

Heat Rise Modeling Bundles in Tray

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

0 50 100 150 200 250 300

Tem

pera

ture

Ris

e (°

C)

Center of Bundle Temperature Rise vs. Cable Count at 100W

Cat 5e UTP Predicted Temp Cat 6 UTP Predicted Temp Cat 6a UTP Predicted Temp

TIA Target

Number of Cables

Hi-Power PoE and Heat

Heat generation from power on cable is a function of: • Power Level

• Cable Resistance Heat transfer out of the cable is a function of: • Cable design and materials

• Installation Environment

Hi-Power PoE and Heat

DC Resistance AWG of conductors (amount of copper)

Cat 6A Cat 6 Cat 5e

Representative conductor diameters

The Insulating Effect of Air

• Cat 6a UTP designs incorporate airspace around cable core to control Alien Crosstalk

• Airspace within cable jacket retains heat

• Tighter twists (aka length) create more heat

Category 6a

Category 6

Some Cables Perform Better Than TSB-184-A

For Type 4 power @ 100W (1000mA/pair) in open tray with cable remaining within listed temperature

Cable Type Max Number of Bundled Cables

Industry Standard Bundle Size for 15°C Rise

Hyper Plus 5e (75°C) 242 52

LANmark-6 (75°C) 285 64

LANmark-2000 (90°C) 331 64

LANmark-XTP (90°C) 534 74

Heat Rise Modeling Bundles in Tray

5e

6a XTP

+17°C

(+30°F)

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

0 50 100 150 200 250 300

Tem

pera

ture

Ris

e (°

C)

Number of Cables

Center of Bundle Temperature Rise vs. Cable Count at 100W

Cat 5e UTP Predicted Temp Cat 6 UTP Predicted Temp

Cat 6a UTP Predicted Temp Isolated Cat 6a Predicted TempCat 6a XTP Predicted Temp

TIA Target

Hi-Power PoE Testing

Temperature Rise Tray vs. Conduit

Pathway Type Temperature Rise °C

Open Cable Tray 16.1

2.5” PVC Conduit 19.9

3” PVC Conduit 20.1

2.5” EMT 23.8

• Temperature rise at 1000mA for 80 cable bundle – Cat 5e UTP

Pathway Geometry Matters

• Bundles and Open Cable Tray behave very differently

Open Cable Tray vs. Bundles

Notes on TIA TSB-184-A

• “Guidelines For Supporting Power Delivery Over Balanced Twisted-pair Cabling” − Targets maximum of 15°C temperature rise −Developed to address installed base of

cabling

• TSB’s are recommendations, not requirements for new installations

New Optional UL Marking

• “LP” – for Limited Power • Cable legend to include “…CMP-LP(0.xA)” • x = Ampacity of the cable

– 0.5A = 100W using 50 Volts over 4 pairs – 0.6A = 120W using 50 Volts over 4 pairs – 0.7A = 140W using 50 Volts over 4 pairs

Note: no current or planned IEEE project to create power levels above

100W

LP Marking Program

• Based on temperature rise of 192 cable bundle enclosed in 6’ of PVC conduit with sealed ends (“Reasonable Worst Case”)

– Power levels increased until cable bundle reaches the cable’s listed temperature (60, 75, 90°C)

– assumes a 30°C ambient temperature

• Goal is to eliminate need for special installation practices based on intended use

2017 NEC Code

• Article 840.160 (Premises Powered Broadband Communication Circuits)

– Refers to 725.144 if power level is over 60W • Article 725.144 – guidance on limiting current and “bundle

size” through proper conductor sizing (AWG) - table of data – LP marked cable is mentioned as an OPTION – No definition of “bundle”

2017 Edition

Hi-Power PoE Recommendations

• For installed base of cabling, a site survey is a must – Look for areas of cable concentration

• Cable trays, floor penetrations, cables entering closet

– Estimate the number of cables based on the OD of the cable type and the size of the pathway

• For new installations – Plan for future Hi-Power PoE deployment

• For best performance install XTP or FTP Category 6A cabling – Provides the best temperature and electrical performance

Why Category 6A? Operational Advantages

• Lower costs by supporting higher power per cable, avoiding additional bundles & trays

• 23 AWG conductors provide better heat dissipation vs. 24 AWG – Cooler temp maintains cable integrity &

lifespan – Reduced OPEX, less facility cooling required

31

Thank You