Paralleling to reduce Voltage drop

[copey84]

Hello, can you parallel conductors to reduce Voltage drop? Got a job were voltage drop is an issue and I can't upgrade cables because of cost. Will paralleling conductors of same csa double the csa and reduce voltage drop, and is it allowed in regs?

 

[westward10]

Yes.

 

[Strima]

And again, yes.

 

[telectrix]

and again, again, yes.

 

[Dillb]

And again, again, again, yes

 

[telectrix]

 

[Deleted member 105166]

Read up on Appendix 10.
To keep things simple, cables should be the same type, CSA and length, don't forget to check the tables in Appendix 4 for derating factor based on installation method.

 

[westward10]

Read up on Appendix 10.
To keep things simple, cables should be the same type, CSA and length, don't forget to check the tables in Appendix 4 for derating factor based on installation method.

Couldn't you just say yes

 

[Deleted member 105166]

Couldn't you just say yes

OK... YESSSS!!!

 

[copey84]

Thanks lads thought it was ok, just wanted it confirmed.
The cabling runs from supply to three d/bs first two are 3phase boards and third is a single phase. Will it be ok to increase the csa on L1 of 3 phase cable between d/b 1 and 2 then increasing single phase csa to d/b 3.
Basically is there any issue having one core on a three phase supply with a larger csa?

 

[westward10]

I'm lost now, can you show a drawing.

 

[telectrix]

I'm lost now, can you show a drawing.

here you go:

 

[static zap]

Things will get un even ,if there is a lack of symmetry ! ( fair shares - for all )

 

[SJD]

Out of interest, where is the extra core you are doubling up for the L1 phase coming from? A core currently used for Earth in the same cable (if this is SWA)?

 

[Marvo]

You can't just increase the CSA of one of the phase conductors of a 3-phase supply, you must also uprate the neutral and earth accordingly. It's also going to get tricky with OCPD's as well...

 

[Rpa07]

@MDJ - lack of initial information from the OP and he led everyone in a merry dance!
No

 

[copey84]

Hi lads thanks for replys. Did think the paralleling of L1 could be a bad idea don't want to risk damaging any equipment.
Have to talk with customer again, only option is cable upgrade.

 

[Lucien Nunes]

If the cables are being paralleled only to keep VD on the most heavily loaded phase within specs, rather than to provide adequate CCC, then there will be no harm electrically. However, you will have a very non-standard circuit configuration that might be difficult to explain on the cert, and things might go wrong if it is modified in the future.

Personally, if I had excessive drop on one phase due to unbalanced load, and a spare core, I'd parallel it with the neutral. A stiffer neutral is always better, and it will do as much to reduce the VD of the unbalanced part of the load as paralleling it with the line. In some applications that generate heavy 3rd harmonic distortion, the neutral has to be larger than the lines anyway.

Do you have any figures to give an idea of how far things are adrift with the existing cable?

 

[Strima]

How many circuits on the single phase board? Could they be split and have that DB as a three phase to help with balancing?

 

[plugsandsparks]

If not already done, i would re-balance first, fit PFC second and then upgrade cable.