Suitable RCCB replacent

[gazdkw82]

I need to replace this old RCCB with a suitable replacement.

Circuit Breaker Specialists

circuitbreakerspecialists.co.uk

Currently the one installed is not tripping on test and from the test point. Changing the entire consumer unit is not financially viable for the home owner at present so I would like to change this to at least reinstate RCD protection.

Any help would be appreciated

 

[bill01803]

Put up front rcd?
Try auction sites for replacement

 

[suffolkspark]

Theres one in your link? Dont expect something of that age to be cheap

 

[gazdkw82]

Theres one in your link? Dont expect something of that age to be cheap

That's why I'm looking at something that may be suitable in its place.

 

[suffolkspark]

That's why I'm looking at something that may be suitable in its place.

You need to fit the one the same back in its place

 

[ChrisElectrical88]

You need to fit the one in your link. That’s a decent price for one aswell, I’ve paid over £100 for them and the RCBOs before.

 

[snowhead]

Nothing else will fit but a Sq D / Schneider of that type.
It's a unique fitting to the bus bars.

Just a note, Schneider changed all the part numbers for the old Sq D stock
QO200RCDX30 will be something else now as the replacement for the clip in type is a din rail type with an adapter.

 

[telectrix]

is that faulty RCD an upfront device, doubling as a main switch? if so fit a stand alone RCD (any brand) In the tails fron the meter.

a secondary concern is that you might have a N-E fault.try testing with the outgoing cables removed.

 

[westward10]

Is it a Quickline I or Quikline II. Are the mcbs brown or white.

 

[gazdkw82]

is that faulty RCD an upfront device, doubling as a main switch? if so fit a stand alone RCD (any brand) In the tails fron the meter.

a secondary concern is that you might have a N-E fault.try testing with the outgoing cables removed.

No its protecting only part of the installation. A split load board.

If there was a N-E fault then the rcd should do its job. If it's not tripping then the rccb is still faulty. There was a good Zs reading on the circuit and no odd voltages across N-E.

That's how I understand it...

 

[telectrix]

a N-E fault on a circuit may inhibit the RCD from operating, both on testing with MFT and the test button. had it a couple of times. once was on an immersion heater cable with a nail in it. once i had dissed the cable from the board, the RCD worked perfectly. on testing the cable, it was a dead short N-E so there was no volts N-E either.

 

[gazdkw82]

a N-E fault on a circuit may inhibit the RCD from operating, both on testing with MFT and the test button. had it a couple of times. once was on an immersion heater cable with a nail in it. once i had dissed the cable from the board, the RCD worked perfectly. on testing the cable, it was a dead short N-E so there was no volts N-E either.

I'll be honest, I dont get that. Iv had rcds that wont hold in because there is a neutral to earth short.

What neutral to earth characteristics would denote an rcd tripping and an rcd not operating at all? Earthing arrangement? Extent of short circuit?

 

[MJPD29]

a N-E fault on a circuit may inhibit the RCD from operating, both on testing with MFT and the test button. had it a couple of times. once was on an immersion heater cable with a nail in it. once i had dissed the cable from the board, the RCD worked perfectly. on testing the cable, it was a dead short N-E so there was no volts N-E either.

Had that too. A bit of head scratching went on before I realised what it was. Disconnected circuit and RCD was fine.

 

[telectrix]

it's weird. i can't explain the science behind it, but it does sometimes occur.

 

[gazdkw82]

it's weird. i can't explain the science behind it, but it does sometimes occur.

How odd, taking into account the theory behind rcds, any neutral to earth should operate the device. I cant imagine any condition where the rcd would not see an imbalance when neutral and earth are shorted in some way....

I think by process of elimination I will still try what you have suggested and rule out neutral to earth fault

 

[suffolkspark]

It can occur if the N E fault is on a non rcd circuit in the same board, somebody once had a link to a diagram of how it occurs

 

[telectrix]

might be on a PME system, the N-E fault could case current to flow through E to MET and as this is strapped to N at the cut-out, backfeed through N to the RCD inhibit it from tripping. only a guess mind. as for above post. if i recall, it was a dual RCD board in one case and both RCD faied to trip.

 

[DefyG]

Dont expect something of that age to be cheap

Was quoted over £200 for a Sq D / Schneider replacement RCBO! .......It was cheaper to replace the board!