Earth-Leakage breakers??

[Mustang]

Hello everyone,

Just wondering is an Earth leakage circuit breaker exactly the same as an RCD? The reason I ask is that I heard someone mention once that Earth leakage circuit breakers do not work very well. Maybe I heard wrong?

 

[sparks1973]

The other thing about the more recent ELCBs is they will say "Controlling L.H. Ways only" on the front - unmistakable.
View attachment 13774Pic is of VOELCB - as mentioned above, if it's one of these, don't tinker, just replace!
The other thing to check is the soundness of the earth rod and cable, and to check the Ra/Ze. Last time I found one of these, I followed the earth cable into the garden, round the shed, into the blackberry bushes, and found it connected to a 12" long piece of 15mm copper pipe via a crocodile clip...Ze was a respectable 60 odd Ohms though .

thats a crabtree...their often still functional.....tenby`s on the other hand.....

 

[DNS1]

If it is a VOELCB then you won't be able to test it with a conventional RCD tester/MFT, as modern RCD's/RCBO's are current opererated, VOELCB's as their name suggests are Voltage operated.

Ah ok, thanks for that. First time I've met a VOELCB!

It's a Chilton BS842 unit and looks a lot more modern than the picture that dorsetspark posted.

Can I simply leave it in place and use it as an isolator, or should it be removed completely? (assuming of course the seal fairies have visited at some point)

If so I'll just swap the DB main switch for a 100mA RCD incommer.

Cheers for the help.

 

[Des 56]

use it as an isolator,

It will likely be a 60 or 63 amp rated device

 

[Knobhead]

As I said earlier use it as an isolator.
If ever you get the chance to take one to bits, you will find the contacts are better constructed than the modern isolators. Just remove the earth connections from the VOELCB and connect to the MET, you’re sorted then.

 

[Taylortwocities]

As I said earlier use it as an isolator.
If ever you get the chance to take one to bits, you will find the contacts are better constructed than the modern isolators. Just remove the earth connections and you’re sorted.

I think Tony means "bring the earth connections up to date". Not "remove".

The old VOELCBs have two earth connections, one goes to the earth (Electrode) and the other goes to the earth bar in the fusebox/CU. If you just remove them then bang goes your earth.

At the very least the two need removing from the VOELCB and joining together leaving the VOELCB as a handy isolator.
You'll need to test Ze, of course!

 

[Des 56]

The construction of a 35+ year old elcb may have been well made and more durable than todays efforts,but the rating of the unit may be lower than that required

You can never be assured that a second hand piece of equipment,that may be underated,will have contacts that are indeed undamaged,even if the rating were to be adequate,you would have to destroy the switch to check for that damage

A 100 amo isolator and enclosure is cheap,rated correctly and new
I would do as recomended and bin it

 

[Knobhead]

I think Tony means "bring the earth connections up to date". Not "remove".

I’ve edited the post to what I meant.

As for the contacts they will be Fault rated. A modern isolator will be Off Load.