Power cut blown MCBs?

[Piers Finlayson]

We had a power cut last night which manifested itself by

- power going for about 10s

- coming back on for about 5s

- going out for about 5s

- coming back

- repeating a few times

- going off completely.

Then came back on about 30 minutes later doing the same tripping thing and then went out again. At about this point I decided it would be sensible to turn off all the MCBs except the lighting so that nothing would get damaged and I would know when the power came back because the lights would be on.

The power did come back on later. However, turning on a couple of the MCBs hasn't resulted in any power on those circuits (cooker and upstairs sockets).

I haven't had a chance to open up the CU and see if anything's come loose, or get my DMM out and start testing - that's for this afternoon/evening, but wondered if it was possible/likely that the power cut has blown these two MCBs. Having moved into a new house 1.5 weeks ago I'm not sure I have any compatible MCBs for this CU >:-(.

(And to cap it all my 5 million candle torch from Screwfix that arrived on Thursday doesn't ****ing work even though I charged it is preparation for a power failure, so I had to find the candles by the light of my laptop.)

[Andrew Gabriel]

It wasn't the power cuts that tripped the MCB's, it was you, right? In that case, I don't think you can blame the power cuts.

Only other thing I can think of is a split load CU, and the RCD has tripped to the protected MCBs.

We had a few severe brown-outs last night, lasting about a second each. Must have dropped below 120V as not all the 120-240V PSU's managed to hold up enough to prevent things rebooting. Lights dimmed but didn't quite go out.

[Stuart B]

I don't know where you get that from ( That it was the OP who was responsible) . Altho' the Op doesn't specifically say so I guess the first power cut tripped the MCB's and then did it again after the OP reset them and it was at that point that the OP decided to switch them off until the power stabilised ( as he said) .

[John Rumm]

What make of MCBs are they? I have found some flakey ones the past that do not always turn on electrically when you flip the switch! Turn them off and on again and you may get a different result.

[Piers Finlayson]

These are Proteus MCBs. One seemed completely shagged the other is, as you suggest intermittent. The intermittent one is upstairs sockets so I hadn't noticed it was intermittent (flip switch, run upstairs, etc).

I've replaced them both with Volex ones which just about fit right.

Of course, then I found that another one is intermittent and now isn't working. A few flips later and everything works. Given my experience of Proteus thus far I'll probably get rid of the whole damn Proteus CU plus MCBs in due course.

(In answer to the other posters it was I what tripped the MCBs in the first place. The power cuts didn't.)

[John Rumm]

Aha! - that name rings a bell....

Of course, then I found that another one is intermittent and now isn't

;-) BTSTGTTS

(well I was not my CU so I left that, but replaced most of the MCBs)

[ARWadsworth]

Just swap the CU. Proteus are about as reliable as a 1980s Lada. You should be able to buy a decent CU with MCBs for about £50.

You can usually shove most makes of MCBs into another CU. Not a good idea though

Good idea

You said that in your first post:)

Adam

[Piers Finlayson]

Nice to know where I stand - thanks!

[Stuart B]

snipped

Doesn't read that way to me ..???

[John Rumm]

How else would you read: "At about this point *I* decided it would be sensible to turn off all the MCBs except the lighting so that nothing would get damaged and I would know when the power came back because the lights would be on" [my emphasis]?

[Adam Aglionby]

[Stuart B]

I've read the OP a few times and am not any clearer .

It says

" We had a power cut last night which manifested itself by

- power going for about 10s

- coming back on for about 5s

- going out for about 5s

- coming back

- repeating a few times

- going off completely.

Then came back on about 30 minutes later doing the same tripping thing and then went out again. "

It was the part " doing the same tripping thing" that confuses me . That suggests to me that the power cut HAD been tripping the MCB's at the earlier points otherwise why use that expression . But who knows ( or cares ) :-)

[Piers Finlayson]

Maybe I'll return for a refund rather than asking for a replacement ...

[Piers Finlayson]

Ah, sorry. I used the term "tripping" there because at the time it seemed like a local substation or something was tripping out and then restarting automatically, which is why the power kept coming back for a few seconds and then going off again. Lady