UK MCB screw won’t undo - what would you do?

[Mindgirl]

Curious what you would do

Screw holding ring final circuits live wires in MCB wont unscrew ,

it’s literally a ground out circle from what was originally a Philips head screw

Therefore couldn’t do end to end continuity
I did end to end from socket instead,

MCB probably needs to be changed, but I couldn’t find any new available.

probably needs whole board change unless there is an alternative compatible McB?
(Also RCD is on last legs as inconsistent results on functional testing)

 

[James]

Think I would leave it if there was no sign of overheating.
Source a replacement breaker.

End to end from a socket proves that it is a ring.

Could have cut and jointed cable after it leaves breaker but I am not a fan of unnecessary joints.

 

[Welchyboy1]

Take the mcb off the bus bar, cut the ring conductors off the mcb
find a replacement mcb(ebay) it is an old Volex copy cu that you got there, so if you don’t find a steeple one, just use a volex they are very common
install mcb, connect ring circuit.... next!

https://www.ebay.co.uk/itm/Volex-VB...408962&hash=item42244ca4ec:g:DIwAAOSw2aJemuKB

 

[GBDamo]

Take the mcb off the bus bar, cut the ring conductors off the mcb
find a replacement mcb(ebay) it is an old Volex copy cu that you got there, so if you don’t find a steeple one, just use a volex they are very common
install mcb, connect ring circuit.... next!

https://www.ebay.co.uk/itm/Volex-VB...408962&hash=item42244ca4ec:g:DIwAAOSw2aJemuKB

Wasn't Steeple a Denmans own brand before they switched to Lewdens?, are the two the same?, will wholesalers ever stop pimping own brand trash before dumping it in favour of something even of even less quality?

All these questions and more may never be answered.

 

[Mindgirl]

Wasn't Steeple a Denmans own brand before they switched to Lewdens?, are the two the same?, will wholesalers ever stop pimping own brand trash before dumping it in favour of something even of even less quality?

All these questions and more may never be answered.

It’s denmans (a rebadged ge) - they don’t make that model and even used on eBay out of stock/no longer available

volex is a good shout, and might avoid whole unit change.
Only issue is RCD would also need changing

 

[Dartlec]

Nothing wrong with doing ring contuinity at a socket.

With the MCB, then assuming it is still making a good firm connection then I'd not worry about it too much. The only issue would be if the connection wasn't sound, then a replacement would be needed.

If the RCD is on it's way too then it's probably time for a new board anyway, at least in the near-medium future.

It does look very similar to Volex, and there are still some of those around - I have some Sector branded ones that look similar too (no 32s unfortunately) so I suspect there may be several 'brands' that fit.

 

[LewisM]

Get some of this on the screw head then give it some

 

[Dartlec]

It’s denmans (a rebadged ge) - they don’t make that model and even used on eBay out of stock/no longer available

volex is a good shout, and might avoid whole unit change.
Only issue is RCD would also need changing

If it's the same as the Series E then there are some on ebay but trying to match existing ones is always a pain and open to difficulty and is likely to only get worse as old stocks dwindle. If they could all at least agree on a standard busbar it would help.

 

[Mindgirl]

Get some of this on the screw head then give it some

.. and hope screwdriver doesn’t stick permanently to screw?

 

[dodger421]

Get some of this on the screw head then give it some

That stuff is magic, but you need to use it pretty early on for it to be effective. If there’s nothing left for a screwdriver to bite on no amount of it will help!

 

[DefyG]

MCB wont unscrew ,

it’s literally a ground out circle from what was originally a Philips head screw

Bl.........dy impact drivers! (Probably)

 

[Megawatt]

Curious what you would do

Screw holding ring final circuits live wires in MCB wont unscrew ,

it’s literally a ground out circle from what was originally a Philips head screw

Therefore couldn’t do end to end continuity
I did end to end from socket instead,

MCB probably needs to be changed, but I couldn’t find any new available.

probably needs whole board change unless there is an alternative compatible McB?
(Also RCD is on last legs as inconsistent results on functional testing)

Get a small drill bit and drill it through and use an easy out. As you guys are saying it’s probably best to be changed

 

[suffolkspark]

It is steeple/denmans but not a re-badged GE, that was the generation prior to this one, these were made by electrium so volex would be an identical fit. I would leave it though, they're steeple boards are now made by lewden as somebody said

 

[Mindgirl]

Thanks all
I’ve left it with client to see if they want board change, although not sure I want to inherit likely problems with house wiring

that particular circuit:
r1 was 200 ohms.
r2 1.3 ohms
rn 0.6 ohms
R1+ R2 was not too bad considering (0.5 ohms)

 

[pc1966]

Get a small drill bit and drill it through and use an easy out. As you guys are saying it’s probably best to be changed

Seems such a common problem they now make them for power tools!
https://www.NoLinkingToThis/p/screw-bolt-extractor-set-2-pieces/2951v
Ironic really, given the power tools probably caused the problem in the first place...

 

[pc1966]

I’ve left it with client to see if they want board change, although not sure I want to inherit likely problems with house wiring

Is the EICR looking rather poorly for them then?

 

[suffolkspark]

Thanks all
I’ve left it with client to see if they want board change, although not sure I want to inherit likely problems with house wiring

that particular circuit:
r1 was 200 ohms.
r2 1.3 ohms
rn 0.6 ohms
R1+ R2 was not too bad considering (0.5 ohms)

Ah that's a C2 all day long then incomplete ring

 

[pc1966]

R1 = 200 ohms is a fire if you put any high load on it!

Doh, this is r1,r2,rn for ring end-end!

 

[Mindgirl]

I would probably say FI (as really needs further investigation)
Client wants to do investigating on their time but it may not be a problem in a socket (They have been warned but he’s a retired nuclear physicist)

I wonder if you do find problem between two sockets but don’t want to look for cable (to avoid making holes) you could disconnect neutral and earth, and have two radials instead (on separate breakers when board changed)

 

[pc1966]

If you can't find the cable route non-destructively to find a dodgy junction box, yes you could split the ring and change to 20A breakers to allow for the lower CCC of the system.

But you would need to be sure to disconnect both ends and check it is not spurred off to somewhere from a hidden junction box. If so one end would need to be kept joined leading to live ends at the other to be made safe and also to verify that you don't have any dodgy high-R connections on that spur route either.

But it might be better to run in another cable to replace the hard-to-find section as that might be a lot easier depending on the property and access to under floor/attic/etc.