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DSLx / G.fast “Reverse Powering” Is Here! “plus how it might be affected by the NEC”

DSLx / G.fast “Reverse Powering” Is Here! “plus how it might be affected by the NEC”. Jim Wiese Senior Compliance Engineer ADTRAN, Inc. 901 Explorer Blvd. Huntsville, AL 35806 256-963-8431 office 256-714-5882 cell Jim.wiese@adtran.com. What is Reverse Power?.

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DSLx / G.fast “Reverse Powering” Is Here! “plus how it might be affected by the NEC”

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  1. DSLx/G.fast “Reverse Powering” Is Here! “plus how it might be affected by the NEC” • Jim Wiese • Senior Compliance Engineer • ADTRAN, Inc. • 901 Explorer Blvd. • Huntsville, AL 35806 • 256-963-8431 office • 256-714-5882 cell • Jim.wiese@adtran.com

  2. What is Reverse Power? Is it Power working backwards or in reverse? Is it connecting loads in reverse? Is it Anti-Power, or some solar thing? NO!

  3. What is Reverse Power? Reverse Power (RP)  describes a technology, and the means by which the power for a “network” communications system device is derived from a power source located at the customers facility (customer premises). This power is then transmitted over communications cables (e.g Tip/Ring or Coax) to the “network” equipment. **This is the “reverse” of the traditional method which involved the network service provider supplying the power and transmitting the power to customer equipment, such as a telephone**

  4. What is Reverse Power?

  5. What is Reverse Power?

  6. What is Reverse Power?

  7. What is Reverse Power?“Characteristics of RP” Defined in ETSI TS 101 548 Uses one Tip/Ring Pair or one Coax cable Power derived from customers modem or power injector One customer modem or power injector can power the Service providers DPU (distribution point unit) As each customer is added, power is shared equally DC Voltage limits are always “supposed to be under 60 Vdc in North America (up to 120Vdc outside North America) Current and Power are tightly controlled by standards (NEC, ATIS, and Product Safety Standards)??? Currently 30 watts is high end (but everything changes)

  8. What is Reverse Power?“Advantages of RP” Easy deployment using “EXISTING” communications cables No changes necessary for existing primary protection or NIDS DPU for 16 customers easily installed Customer can self-install modem. (no service person required) Power can be backed up by simple UPS located near modem Safe as less than 60 Vdc Low current, low risk of fire Can be used with G.fast, VDSL, or future copper broadband technologies Meets Telcordia Standards, Safety Standards, etc. NEC compliant (at least through December 2017)

  9. What is Reverse Power?“Disadvantages of RP” Relatively short distances (IR loss) Can be a challenge to protect from lightning and AC induction Can be very complex if lifeline POTS is required Considered unfair by some, as customer is paying for power to power the service providers DPU ( not different from ONT’s?) May be rendered unfeasible by recent changes in NEC 2017 and future 2020 code???

  10. Reverse Power“GR-1089-CORE” Considered a Type 3b/5b (since <300m) Class A2 voltage source (>30Vdc and <80Vdc) Can have externally applied primary protection Can have Integrated OR Embedded Primary Protection GR-974-CORE, GR-1361-CORE cover Primary Protection

  11. Reverse Power“UL 60950-1 and UL 62368-1 (-3)” No problems Meets TNV 1 or ES1 Class A2 voltage source (>30Vdc and <80Vdc) Can have externally applied primary protection Can have Integrated OR Embedded Primary Protection Neither safety standard address primary protection as it is assumed the protection is installed by a service provider elsewhere. (UL 497)

  12. Reverse Power“NEC (NFPA 70) ” • Falls under Article 840 – Broadband Premises Powered • 840.48 – entrance cables (unlisted) • 840.160 – Special Permission Section to allow “powering circuits” on Communication Cables in 840. Examples: • ONT UPS Power/Alarm Cable • POTS • Sealing Current • Service Provider Equipment Powering of remote equipment • 840.170 – Voltage, Current, Power, Listing limitation section

  13. Reverse Power“NEC (NFPA 70) ” • Interesting information and issues in General with 840 • Per definitions and scope, the installation must include: • a “communications circuit” • a “network terminal” • a system “powered from the premises” (customers power) • a system that is “broadband” (what is broadband) • a “service provider” • a “‘communications utility” (via reference to 800.2) • However, the recent work and battles on 840 are about situations (i.e. PoE) that often do not involve one or more of the above conditions and rarely a traditional telecom service provider

  14. Reverse Power“NEC (NFPA 70) ”

  15. Reverse Power“NEC (NFPA 70) – 840.170” No problems here for reverse power Oddity is that the exact same equipment and cabling is also now addressed by 725.121(A)(4) for ITE equipment. 725.121 is used if the conditions for using Chapter 8 or particularly 840 are not met 725.121(A)(4) has totally different requirements for Voltage, Current, Power, that conflict with ITE safety standards, Telcordia, ATIS/ANSI standards (i.e. ATIS 0600337) PI submitted last fall by Jim Wiese with assistance from Ernie Gallo to move and harmonize the 840.170 criteria to ITE equipment in 725.121 (A)(4) – status unknown

  16. Reverse Power“NEC (NFPA 70) – 725.121(A)(4)”

  17. Reverse Power“NEC (NFPA 70) – 840.170(A)(4)”

  18. Reverse Power“NEC (NFPA 70) – Table 11b”

  19. Reverse Power“NEC (NFPA 70) – 840.160 (prior to 2017)” “840.160 Powering Circuits Communications cables, in addition to carrying the communications circuit, shall also be permitted to carry circuits for powering communications equipment “ • No problems: • No restriction on what cables defined in 840 can have power • Other areas of 840 define Listing requirements explicitly • No limitations on the power or current (other than safety standards (Listing) , and 840.170/Table 11b) • No references to 725.144, or 725 at all (chapter 8 independence) • All is good for systems deployed under the jurisdiction of 840 and specifically 840.160 by those who are allowed to use 840!

  20. The Problem

  21. NOT the Problem

  22. Reverse Power“NEC (NFPA 70) – 840.160 (2017 before Cisco appeal 12/17)” • Problem was bundled PoE • Solution barely touched PoE • Only affected other services above 60 watts. Mostly MDU ONT’s and some communications powering systems to power equipment on upper floors of multi-floor buildings and multi-telecom room single buildings > 60 watts • Cisco fought this with several TIA’s and an appeal they won in Dec 2017 , language changed

  23. Reverse Power“NEC (NFPA 70) – 840.160 (2017 after Cisco appeal 12/17)” 840.160 Powering Circuits Communications cables, in addition to carrying the communications circuit, shall also be permitted to carry circuits for powering communications equipment. Installations of listed communications cables shall comply with 725.144 where listed communications cables are used in place of Class 2 and Class 3 cables. Exception: Compliance with 725.144 shall not be required for installations of listed 4-pair communications cables where the nominal current does not exceed 0.3 amperes in any conductor. • Problem was bundled PoE • Solution exempts all standardized PoE • Now affects ANY other service with power on communications cables not using a 4 pair LAN style cable • Now all ONT’s, reverse powering and other service with power are affected (and they are not bundled or the problem)!! • Service providers effectively lose the 90.3 exclusion (independence of Chapter 8)

  24. Reverse Power“NEC (NFPA 70) – 840.160 (First draft 2020)” 840.160 Powering Circuits Communications cables listed in accordance with 800.179, in addition to carrying the communications circuit, shall also be permitted to carry circuits for powering communications equipment listed in accordance with 800.170. The power source shall be listed in accordance with 840.170(G).Installation of the listed communications cables shall comply with 725.144 where communications cables are substituted for Class 2 and Class 3 cables in accordance with 725.154(A). Exception: Installing communications cables in compliance with 725.144 shall not be required for listed 4-pair communications cables where the rated current does not exceed 0.3 amperes in any conductor 24 AWG or larger. Informational Note: A typical communications cable for this application is a 4-pair cable sometimes referred to as Category 5e (or higher) LAN cable or balanced twisted pair cable. These types of cables are often used to provide Ethernet and Power over Ethernet (PoE) type services. A large number of such powering cables bundled together can cause overheating of the wiring if not controlled as described in Table 725.144.

  25. Reverse Power“NEC (NFPA 70) – 840.160 (First draft 2020)” • Problem was bundled PoE • Solution exempts all standardized PoE • Still affects ANY other service with power on communications cables not using a 4 pair LAN style cable and affects the service providers even more! • Service providers effectively still loses the 90.3 exclusion (independence of Chapter 8) • And a new big problem for reverse powering, or any powering using entrance cables 840.160 Powering Circuits Communications cables listed in accordance with 800.179, in addition to carrying the communications circuit, shall also be permitted to carry circuits for powering communications equipment listed in accordance with 800.170. Currently any communications cable described in 840 can have a powering circuit! But this new language seems to only give permission to Listed cables and thus unlisted entrance cables seem to be banned from having a powering circuit and can only have voice, and data.

  26. Reverse Power“NEC (NFPA 70) – 840.160 (Total Solution)” 840.160 Powering Circuits Communications cables covered in 840.48 and, communications cables listed in accordance with 800.179, in addition to carrying the communications circuit, shall also be permitted to carry circuits for powering communications equipment listed in accordance with 800.170. The power source shall be listed in accordance with 840.170(G). Installation of the 4 pair listed communications cables covered by Table 725.144, shall comply with Table 725.144 where the term communications cables are substituted for the terms Class 2 and Class 3 cables in accordance with 725.154(A). Exception: Installing communications cables in compliance with 725.144 shall not be required for listed 4-pair communications cables covered by Table 725.144 where the rated current does not exceed 0.3 amperes in any conductor 24 AWG or larger. Informational Note: A typical communications cable for this application is a 4-pair cable sometimes referred to as Category 5e (or higher) LAN cable or similar balanced twisted pair cable. These types of cables are often used to provide Ethernet and Power over Ethernet (PoE) type services. A large number of such powering cables bundled together can cause overheating of the wiring if not controlled as described in Table 725.144.

  27. Reverse Power“NEC (NFPA 70) – 840.2 (First draft 2020)” New Concern, definition of service provider being added: Service Provider – any business, entity, or person performing a service for others. • This is very disturbing! • Can AT&T or CTL do installations at their own facilities? • Seems my wife can use 840 to install equipment for her neighbor or anybody else and she knows nothing about telecom equipment!

  28. Questions???

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