With Great Power Over Ethernet Comes Great Responsibility PRESENTED BY Bob Crain

Transcription

1 With Great Power Over Ethernet Comes Great Responsibility PRESENTED BY Bob Crain

2 Pathways and Spaces Planning for a PoE Environment IEC 2018 Bob Crain

3 With Great Power Over Ethernet Comes Great Responsibility Agenda Data Cabling Current TIA Standards NEC 2017 PoE Data cabling Ampacity Fill and Bundling Standards Evolution

4 Requirements are Changing! Systems are Integrating!

5 TIA-569-Open Pathways (Current Standard) ülimit Conduit Use Use of conduit The use of conduit as a horizontal raceway system for telecommunications cabling is considered when: it is required by code, outlet locations are permanent, device densities are low, special mechanical protection is required, or flexibility is not required. In-floor conduit systems are especially inflexible as they are usually buried in concrete. üj Hook 5 Spacing Max 9.8 Non-continuous support Non-continuous supports shall be located at intervals not to exceed 1.5 m (5 ft).

6 TIA-569-Open Pathways (Current Standard) üaccess Requirements and Power and Data Separation Trays may be divided with a barrier to allow for physical separation between power and conductive telecommunications cables. Power and telecommunications cables shall be installed per electrical code. A minimum of 200 mm (8 in) access headroom shall be provided and maintained above a cable tray system or cable runway. The recommended access headroom above cable trays and runways is 300 mm (12 in). Care shall be taken to ensure that other building components (e.g., air conditioning ducts) do not restrict access. üreference NEMA VE2 NOTE NEMA VE2 contains useful information regarding additional cable tray support and installation. ücable Tray Fill 25-50% Cable trays Cable trays shall be planned for an initial maximum calculated fill of 25% (see example 1). The maximum fill of any cable tray shall be 50%. The maximum fill depth of any cable tray shall be 150 mm (6 in). NOTE A calculated fill of 50% for four-pair and similar diameter cables will physically fill the entire tray due to spaces between cables, and random placement.

7 TIA-569-Open Pathways (Current Stds for Data only) 50% Fill is Full! ünec or TIA - 50% Max Fill Let s Do the Math Example: ü2 x 6 Cablofil Wire Mesh = 12 sq in of area üper NEC 50% rule 12/2 = 6 sq in space for cables ücat 5e Cable =.21 in (DIA) = 3.14(.21)2/4= 0.4 sq in ü6 sq in /.04 sq in = 150 cables So what does 150 cat 5e cables look like in a 2x6 wire mesh tray? Cable bundling is very common for data cables No size rules for cable bundles for data cables

8 Current Power is limited Watts and Amps TIA focused on Watts NEC focused on Amps POE standards 1993 IEEE 802.3af - 13W (350 ma) 2009 IEEE 802.3at W (600mA) 2017 NEC Greater than 60W requires limitations

9 NEC 2017 PoE (Section 725) Cable Bundles ücable Type Separation ü Class 2 or 3 circuits require barrier from Power, Class 1, Lighting ü No strapping cables to conduit ücable Ampacity and Bundle Sizes ü Limited to capacity of cable gage & connectors ü No derate for Loose Fill

10 NEC 2017 PoE (Section 725) vs 392 (Data non PoE Cat 6 cables) üspace requirement Class 2 or 3 circuits ü DATA ONLY (.22 dia -24 AWG) ü 2x24 space 636 cables ü Limited by physical space available ü POE ONLY (.22 dia -24 AWG) ü 2x24 space 636 cables ü Limited Ampacity based on bundle size ü ½ POE + ½ Data (.22 dia -24 AWG) ü 2x24 space 636 cables loose fill only

11 Why the focus on amps? Safety Cable overheating Items to address % of PoE deployment How many cables are PoE? How many are data only? Cable Management Techniques Loose fill vs cable bundle conflict Loose Fill = Sloppy = cables run cooler Cable Bundles = Neat and Workman like = derating

12 Why the focus on amps? Safety Cable overheating Items to address Cable type matters Twist Insulation thickness = larger diameter cooler Construction type (Foil wrapped = best at heat dissipation) Pathway system matters Closed systems vs Open systems No suprize open systems run cooler Steel conduit most heat rise (not a thermal sink)

13 Why the focus on amps? Safety Connectors RJ45 Current Limitations Redesigns and testing Alternate Connector designs Disconnection under load

14 Why the focus on amps? Safety End User Concerns Faceplate designations PoE connection Non-PoE connection Patch cord specification Marking Voltage drop Power at device Power at source

15 New Addendum to TIA-569 (Pathway & Spaces Standard) Additional considerations for supporting remote power over balanced twisted pair cabling ütia TR-42.3 subcommittee is working hard on a 2 nd addendum to the 569 Pathway and Spaces standard ü40% fill max üfocus on Bundled and Un-Bundled state (24 cable bundle max) ütable for guidance on heat dissipation depending on cable quantity and bundles. ürj45 rated for 2.0 amp (new connection designs in review to allow greater ampacity) üno Disconnecting under load

16 ALL About Power Watts vs Amps TIA focused on Watts NEC focused on Amps POE standards Evolution 1993 IEEE 802.3af - 13W (350 ma) 2009 IEEE 802.3at W (600mA) 20xx IEEE 802.3bt - 9 Power classifications

17 ALL About Power

18 Future Power over balanced twisted pair cabling üpoe will continue to grow üpoe is a dramatic technology shift üpoe Connectivity is critical (Life safety not just performance) üadditional coordination of NEC/TIA required ücable installation techniques will need to be reviewed & revised ümust plan! Can no longer pull cables until its full üpower cable rules will apply to data cables! ü Data cable voltage drop calculations (length * twist rate factor) ü Data cable ampacity calculations ü Data cable connection fill calculations ü Data cable splice/connection heating tests ü Must mark/label/inform users ü Must mark/label/inform users

19 19 Questions? For more Information: Visit us in Booth #

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