2. Exit REMOTE POWER SYSTEM ”Turning your copper into gold”

3. Eltek 2 What? Powering remote electronics utilizing the existing copper network Also known as ‘span power’ or ‘line power’ Powering a broadband/xDSL network Increased bandwidth requires active components (DSLAM) closer to the end user Solutions for power distributions required

4. Eltek 3 What? CO site with existing 48Vdc system and battery backup Typical distance to remote DSLAM site is 5 to 10km

5. Eltek 4 Remote Powering concept Fed by existing 48Vdc or integrated Rectifier solution AC or DC n numbers of Remote Nodes Typically 5 – 10 km Central Office Remote DSLAM NODE Existing twisted pairs now made available for power distribution. ±190Vdc, 250mA Dc/dc converter in the Remote End supplying -48V

6. Eltek 5 Why? CAPEX & OPEX reductions Utilize the existing infrastructure Copper network, X-connects, etc. Eliminate the requirement for batteries and local power utilities Reduces the size of the DSLAM significantly Battery maintenance eliminated Increased speed of xDSL roll-out

7. Eltek 6 How? RFT: Remote feeding telecommunication circuit Remote Power feeding standard: IEC60950-21/GR-1089 Power limitation: 100W per channel (circuit) RFT-C circuits: Max. 60 mA, maximum 1667V (100VA) normally limited to 800V OR RFT-V circuits: 200Vdc referred ground (400Vdc potential) OVS and ground leakage current detection Eltek only have this type of equipment, why?

8. Eltek 7 How? Block schematics based on Eltek products

9. Exit Modules System Solutions Flatpack DC/DC Converter 48/190 Flatpack VA Limiter Remote End Converter Flatpack RPS Integrated

10. Eltek 9 Flatpack DC/DC Converter Input: 48Vdc (40-60Vdc) Output: 190Vdc of 1250W Reliable ”Flatpack” technology Digital current sharing Short circuit proof High temp protection Over voltage shutdown Part no.: 241114.501 Flatpack VA Limiter Input: ±190Vdc Output: ±190Vdc 12 Channels (RFT-V Circuits) of 100W (250mA) Current limiters Over voltage protection Ground leakage current protection (trip current 60mA) 1.000.000h MTBF per channel Part no.: 241258.724 Central Office modules CE, UL and NEBS approvals IEC/UL60950-21 (”remote powering safety standard”)

11. Eltek 10 VA Limiter I+ CURRENT SENSE I- CURRENT SENSE On/Off switch Over load detection Ground leakage current detect Over load detection Over voltage protection Secondary protection; gas discharge tube +190V input from dc/dc converters -190V input from dc/dc converters Current limiters for lightning and AC power fault protection

12. Eltek 11 Remote End Converter 5 separate DC/DC converters Primary surge protection integrated Input voltage: 190V-380V Output voltage: 48V Output power: up to 380W depending on site layout (typically 250W) Flexible mounting, eats no space in DSLAM rack Part no: 241258.722

13. Eltek 12 Flatpack RPS 2U Integrated 2U Integrated 2 DC/DC Converters 2 VA Limiters 24 output channels (RFT-V Circuits) Single or dual feed 19”/23” mounting 3U solution with Redundant DC/DC converters is also available

14. Eltek 13 Flatpack RPS 6U Integrated Flatpack 6U Integrated Building block for larger cabinet solutions and expandable systems Up to 6 DC/DC Converters Up to 6 VA limiters Up to 72 output channels 48Vdc feed configurable on site 1 x 250A 3 x 100A 6 x 50A

15. Eltek 14 Real CO site with RPS

16. Exit Site installation System dimensioning

17. Eltek 16 Safety Crossover between telecom and power Above 60V SELV level Important Qualification & identification of twisted pairs Training of installation and maintenance people Follow Eltek installation manuals (including the configuration tool) Grounding of people working on cables is important!

18. Eltek 17 Safety – Voltage levels Classification of voltage levels (GR-1089) A1: 200Vdc / 0.15mA maximum leakage current to ground A2: 200Vdc / 5mA maximum leakage current to ground A3: 200Vdc / 10mA maximum leakage current to ground

19. Eltek 18 Safety – DC IEC 60947-1 – Effects of current on humans beings and livestock (DC)

20. Eltek 19 Safety – DC Dangerous area Our area

21. Eltek 20 Safety – AC Remember difference between DC and AC 30mA AC is accepted as trip current

22. Eltek 21 Safety – Body resistance 2kΩ 1,275kΩ

23. Eltek 22 Safety - Earth leakage detection VA Limiter takes care of the safety in the system, on earth fault it trips on 60mA 190V/2,5kohm ≈ 72mA -> earth fault 2kohm (typical person) + 0,5kohm (typ. cables) If the earth leakage current exceeds 60mA, the VA Limiter shuts off within 5ms and runs in a hick-up mode limiting the average current to ground to less than 5mA.

24. Eltek 23 Safety – Overload Isolated (non grounded) person/user (should not happen..) 380V/1,275kohm ≈ 300mA VA limiter channel will go into overload and shut down, but...

25. Eltek 24 Safety – Marking X-connect example Proper marking DSLAM cabinet

26. Eltek 25 Safety – cable qualification From Eltek User Guide

27. Exit Basic electrical considerations Block diagram Fixed Parameters Remote End Converter Line Impedance Stability criteria's

28. Eltek 27 Block diagram Remote site 190V-380V/48V DC/DC Converters Remote Unit Central Office VA Limiter VA limit +190 48V to DSLAM Cable length [m, km, kft] Line impedance [Ohm] Vco [V] Vremote [V] I [mA] VA limit GND -190

29. Eltek 28 Fixed Parameters Central office voltage ±190Vdc = 380V Max current Derived from max output power, safety requirements (GR-1089-CORE, IEC/UL60950-21): 100VA (W) per channel 380V Imax = Pmax/Vco = 100W/380V = 263 mA Safety margin and tolerances must be taken into account The maximum input current of the Remote End Converter must be limited to less than the maximum output current of the VA Limiter (next slide)

30. Eltek 29 Fixed Parameters cont’ Maximum Tolerance VA Limiter (5%) Worst case maximum output current VA Limter Worst case maximum input current Remote End Tolerance Remote End Converter (1%) current 263 mA 238 mA 235 mA

31. Eltek 30 Remote End Converter Max input current: 235 mA Efficiency: ~86% This steals power from the CO Power out = 86% of Power in Pin = Vin * Iin losses Output input

32. Eltek 31 Line Impedance Specific resistance for copper: 0.018 Ohm/mm 2 /m (at 30°C) Resistance per km/kft for Cable size: 0.9 mm (AWG 19): r=27.6 Ohm/km, 8.4 Ohm/kft 0.6 mm (AWG 22): r=55.3 Ohm/km, 16.8 Ohm/kft 0.5 mm (AWG 24): r=87.8 Ohm/km, 26.8 Ohm/kft 0.4 mm (AWG 26): r=139.7 Ohm/km, 42.6 Ohm/kft Max impedance: The maximum line impedance is calculated from the stability criteria Next slides

33. Eltek 32 Stability 1 The obvious The power consumption has to be less than the power available If the power consumption exceeds the power supplied, the power train will collapse

34. Eltek 33 Stability 2 Dc/dc converters has inverse impedance characteristics (1/R) The load is constant If the input voltage drops, the converter will draw higher current to maintain the output voltage (with a constant power load) When the converter draws more current, the input voltage will drop further... Constant power load Constant power:

35. Eltek 34 Stability 3 Too high line impedance will result in decreasing output power for increasing current Unstable!

36. Eltek 35 Line Impedance cont’ Now we can find maximum cable length: AWG 19: 13.6 km / 44.7 kft AWG 22: 6.8 km / 22.3 kft AWG 24: 4.3 km / 14.0 kft AWG 26: 2.7 km / 8.8 kft To increase length pairs can be paralleled 2 pairs – double length 3 pairs – triple length

37. Eltek 36 Paralleling of pairs Cable resistance is increased The current is shared between the pairs If the cable resistance is equal, the current is shared equally The touch current remains the same Only single wire out of and into the modules connectors

38. Eltek 37 Line Impedance cont’ How does the line impedance affect the output power? Linearly decreasing with increasing line impedance

39. Eltek 38 Line Impedance cont’ Knowing the max line impedance, the minimum power per channel can be calculated

40. Eltek 39 Configuration Site dependent parameters Power consumption How many channels? How many pairs? Wire gauge Calculated parameters Max line impedance Max Cable length

41. Eltek 40 Site Dependent parameters Power Consumption This is what the power system do; deliver a certain amount of power to the Remote End How many channels? Adding channels means adding power How many pairs? Adding (parallel) pairs means increasing cable length Wire gauge As seen, the wire gauge affects the line impedance. Use as low AWG as possible...

42. Eltek 41 Calculated Parameters Max line impedance The maximum line impedance is calculated from the maximum power drop of the lines Max Cable length The cable length can easily be calculated from the maximum impedance as long as you know the gauge

43. Exit Excamples – Cable Calculator tool