Neutral not used?

glynnis · Jan 10, 2011

Doing a PIR and come across 3 supplies connected as 3PH-N end earth at DB, but neutral not required or used at machine end and has heat shrink over the end of it at the machine end.
My question is, shouldn't the N conductor be grounded at the DB end instead of in the N bar as it would be a problem if the heatshrink fell off?

IQ Electrical · Jan 10, 2011

glynnis said:
Doing a PIR and come across 3 supplies connected as 3PH-N end earth at DB, but neutral not required or used at machine end and has heat shrink over the end of it at the machine end.
My question is, shouldn't the N conductor be grounded at the DB end instead of in the N bar as it would be a problem if the heatshrink fell off?

Technically yes, the neutral should be terminated at the isolator, I don't know why you use the term 'grounded'.

What is the chance of heat shrink sleeving falling off?

Code 4 IMO

glynnis · Jan 10, 2011

No neutral terminal at machine isolator, only 3 pole.
Use the term "grounded" as in, down to earth at the board end, not neutral, as it would be classed as a spare conductor and could get an inducted voltage, as i have on a pair of strappers wired in t&e with the cpc cut off at both ends(190V to earth when tested).
Was thinking of a Code 4 aswell, but just after another opinion.

IQ Electrical · Jan 10, 2011

Yes, code 4 and the NICEIC do like unused connections terminated into the earth bar and labelled (are you NICEIC?)

I'm interested in the 190 Volts point, I've seen capacitive coupling creating a voltage like this before on good long runs but never to that sort of value, how long are the strappers?

glynnis · Jan 10, 2011

IQ Electrical said:
Yes, code 4 and the NICEIC do like unused connections terminated into the earth bar and labelled (are you NICEIC?)

I'm interested in the 190 Volts point, I've seen capacitive coupling creating a voltage like this before on good long runs but never to that sort of value, how long are the strappers?

NIC with old company, on my own again so looking to re-apply when have some more money.
190V tested fro DB to switch where cpc's cut off, all in plastic sw box, so whoever did the whole floor cut off the cpc's at all switch boxes, some are connected at light fittings, think they forgot about the strappers and cut the lot off! it is about a 30M length but bunched above ceiling with lots of other supplies,single & 3Phase.
Are going back at weekend to sort it out!!