Voltage Operated Earth Leakage Circuit Breaker

[BathSparks]

An old fuse board with only 4 fuses 1 5amp, 1 15amp and 2 30amp fuses has a VOEL CB as the ADS for the whole board. I was adding to an outside circuit, one more light, using SWA cable and whisker boxes for a junction.

When I came to testing, I was not sure how to test VOL CB. I have a Metrel multi-function tester and when I measured the loop impedence, the VOL CB tripped immediately. I do have a setting on the Metrel for these occasions that does not trip an RCD.
I did a functional test and all was well.
All other tests were fine.
I can go back and do an RCD test, but is this compatible with the type of CB we have here. :confused5:

 

[telectrix]

replace it with an RCD. only solution.

 

[malcolmsanford]

If it is voltage operated ELCB, and it is easy to tell, the earthing conductor will go through the unit, the current operated ELCB, which is an old RCD basically will just have a LINE/NEUTRAl going to it.

Voltage operated units, can not be tested by a MFT, as you need to induce a voltage across the coil of about 50volts and you would need an old tester for that. The IET now no longer recognize these units, and recommend change, as they were notorious for either tripping if someone looked at it sideways, or never trip at all

 

[BathSparks]

Thanks. You are right of course but looks like I have opened up a right can-o-worms. May end up replacing more stuff agh!

 

[telectrix]

anyway, your outside light circuit needs RCD protection to comply with regs. so you've got no choice.

 

[malcolmsanford]

Is that because you expect the system to be a TT Tel

 

[telectrix]

nope. slipped up. was thinking not attached to main building , but that's notifiable, not necessarily needing RCD. DOH. excuse is that i've not had beer yet.

 

[ezzzekiel]

also main bonding creates parallel paths that can cause the voelcb not to function had the same conundrum recently which went from just adding a spur to replacing voelcb, upgrading earth rod, main bonds, rewiring or making class2 all lights suffice to say the landlord decided the best option was not to fit the spur