Solar Booklets

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19. De-rating factor: As per IEC or TUV specification. Also as per IEC216, if the cable is over loaded, for 8 C increase over the rated temperature, the cable life is

reduced to 50%. If the temperature rise is more than 8 C, proportionately insulation resistance of cable weakens and thus the premature failure of cable occurs.

20. Non standard cable size: Siechem is specialized in making any cable size as per customer requirement from 0.25 to 1000 Sq mm.

21. EBXL XLPO Solar cable life: 25 years minimum or 20,000 hours continuously at rated temperature, i.e. -45 to + 120 C. Hence, reliable under severe and hostile

operating conditions

22. Cost: Marginally high due to E-beam cross linking and better insulation and sheathing material used for 25 years guaranteed life. Since copper dominates nearly 90%

of weight in case of higher size cables, the gap between ordinary 90°C XLPE cables and XLPO 120 C rated will be very little. But, performance is 30% more than

conventional cables. Therefore, EBXL XLPO is more economical in a long run.

23. Where EBXL XLPO is used: In USA, Europe and in India. Most of the Solar customers go in for this technology.

24. Where XLPE cable is used: In USA, XLPE 90 C stranded annealed copper cables also used where class 2 conductors are considered and cable is installed in

Under Ground. Due to very high ambient temperature conditions in India, Siechem has developed 125 C XLPE cables also, which is cheaper than XLPO.

25.Reference standards: UL and TUV. Siechem makes cables as per both specifications.

26. Design & cable size: This is the key area. It is up to the Engineering Team who smartly design the cable route and sizes. Siechem can supply any cable size that

meets that particular site conditions. For e.g. standard cable is

240Sq.mm.

If the site needs 177 Sq mm, Siechem can do it. This will reduce cost per MW in smart

cable size and length designing.

27. Litigation: The contractors may wash their hands off to their clients whether Govt. agencies or private customers, if customer specified PVC or XLPE cables with relevant

BIS specifications in their tender as BIS is yet to come up with specification for Solar applications. Therefore, when 25 years warranty is called for with guaranteed 80%

wattage after 25 years of service, it is suggested that time tested cables are specified as mandatory requirement in the tender schedule that meet relevant UL 4703 or

TUV 2Pfg 1169/08.2007 specifications whether Indian cables tested in USA or Germany or even in reputed laboratories in India like CPRI, ERDA & NTH etc. as minimum

requirement for use in Solar systems.

Temperature Rating

At 40°C ambient, if the load is 80% of the

rated cable size for

e.g.120Sq.mm

copper

cable, the temperature of the conductor

and current will be

At 55°C ambient, if the load is 80% of the

rated cable size the temperature of the

conductor will be

Current loading @ 80% of the cable

capacity

Same size conductor

i.e.120Sq.mm

if it

is 100% loaded over the cable capacity

(43% more in case of EBXL XLPO Vs

PVC or PVC FRLS cables)

XLPO (EBXL)

PVC

70 C

56 C

244A

71 C

100%

305A

90 C

72 C

267A

87 C

97%

336A

XLPE (EBXL)

120 C

96 C

350A

111 C

92%

437A

Compound

Wires & Cables