Old installation

[Davep01]

Hi,

I went to go and look at a job replacing a consumer unit. It is a TT system, with an old Wylex board. It is protected by an old earth leakage device as described in the post I have attached. Would it be acceptable to leave this connected and then have a RCD protected board in series. It would just make things easier because I could use it as a point of isolation.
I only had a quick look at the job but I will be go back tomorrow to have a bore in depth look.

If if anyone has any advice it would be greatly appreciated.

Thanks,

Dave

 

[Plonker 3]

Do you mean a VOELCB?

 

[Davep01]

Yes, I think so.

 

[Welchyboy1]

Hi,

I went to go and look at a job replacing a consumer unit. It is a TT system, with an old Wylex board. It is protected by an old earth leakage device as described in the post I have attached. Would it be acceptable to leave this connected and then have a RCD protected board in series. It would just make things easier because I could use it as a point of isolation.
I only had a quick look at the job but I will be go back tomorrow to have a bore in depth look.

If if anyone has any advice it would be greatly appreciated.

Thanks,

Dave

I Dont suppose it would do any harm really, but would look a bit naff

i would personally remove it

 

[telectrix]

replace volcb with a 100A 100mA S-type RCD in enclosure.

 

[ImpededLoop]

replace volcb with a 100A 2 pole isolator in enclosure.

As Tel says. Sometimes the old volcb's won't reset so it's best to get rid of it.

 

[Davep01]

Ok thanks. That's what I will probably have to do. It's just there is obviously no other means of isolation apart from the cut out.

 

[Plonker 3]

no other means of isolation apart from the cut out.

Dont worry you wouldnt be the first or the last to use that as a method of isolating the supply so you change the DB.

 

[Engineer54]

Hi,

I went to go and look at a job replacing a consumer unit. It is a TT system, with an old Wylex board. It is protected by an old earth leakage device as described in the post I have attached. Would it be acceptable to leave this connected and then have a RCD protected board in series. It would just make things easier because I could use it as a point of isolation.
I only had a quick look at the job but I will be go back tomorrow to have a bore in depth look.

If if anyone has any advice it would be greatly appreciated.

Thanks,

Dave

May be worth contacting the DNO to see if a PME connection is now available for this old TT supply.

On TT installations it's always prudent to provide an up front 100/300mA S type RCD as a backup for the 30mA RCD's where the Ra values are, or above high single figure values....

If you were to use the old VOELCB purely as a DP isolator then all earth connections to the breaker need to be removed, just remember they are generally rated for 60A (more than enough for most domestic installations)....

The old VOELCB's were notorious for not being particularly good at what they were being installed for, they either never saw a real leakage problem, or were tripping out randomly on phantom leakage. As you can only test these breakers with a dedicated tester and those testers have now been out of production for a good 35 years or more, they should always be taken out of service as a means of earth leakage protection....

 

[Knobhead]

As an isolator the old VOELCB's can't be bettered. They are ON LOAD switches which modern isolators aren't.

Remove the earth link through it and there is your isolator.