MCBs on.. But still power?

[enpassant]

Hello all,

I've searched the forum before asking but coming up empty handed??

I have a power cut from earlier. Live in a flat with a joined kitchen / living room and heard a bang from around the boiler area, then darkness.

Checked the CB's and had 2 tripped which were "B circuits" and lighting. The main 100A MCB was still in, but no power anywhere in the flat.

I've put both CB's back in and still nothing. I have no CB's off now but still the flat is dead. Checked with neighbours as I thought maybe it was the supply and we were all down but they're good. So MCB in and subsequent CB's in but still nothing... Can anyone please advise?

 

[Leesparkykent]

Your board looks like it’s fed by an armored cable (black one entering the board at bottom) this means the meter is probably external to your flat? If so go to your meter cupboard which is probably in the communal area and there will probably be a switch fuse or circuit breaker supplying your flat. My bets would be it being a circuit breaker that’s tripped by your meter because if it was a fuse I doubt it would of blown.

 

[snowhead]

Before you go to reset elsewhere switch off the 2 that were tripped

 

[westward10]

Does anything happen when you press the yellow buttons on the rcds.

 

[KEV 1 N]

Just for future reference, the red 100a main switch is only a switch, it will never trip on overload or a short circuit fault.
As Westward10 has asked a good question, if the yellow buttons cause the RCDs to trip....then there is power present at the DB, if they don’t, then you have no power.

 

[enpassant]

Cheers. Tried to find it but think it's downstairs in a locked cupboard which I can't get access to (no access to meter as is inclusive with tenancy.)

Waiting on someone coming out to it, but that's been since around half 5, so guessing won't see him or her tonight.

Yeah, cheers snowhead, I would've switched them all off before I did but since can't get access I'll need to wait it out.

Westward 10; I did try resetting them but nothing.

 

[enpassant]

Cheers KEV1N, looking St it now it's obvious but yeah, I had thought it was a breaker. Noted.

Podging the RCD's doesn't do anything so guess it's the waiting game for me!

 

[buzzlightyear]

Look to me a new c/ u. has gone in ,the question is why you have no electric.cause the fault is greater on the circuit has taken out the sub main fuse .

 

[The Ghost]

Hi @enpassant just to while a few minutes away while you are there candle in hand awaiting succour, En Passant, I am teaching my grandsons chess and was trying to remember exactly how the En Passant rule worked, do you know?

 

[Midwest]

Expect his batteries gone flat by now.

 

[static zap]

....how the En Passant rule worked, do you know?

Two moves in 1 go , taken on the fly mid move ?

 

[Silly Sausage]

Cheers. Tried to find it but think it's downstairs in a locked cupboard which I can't get access to

Time to embark on your new hobby ...
How to Pick a Lock: The Absolute Beginner's Guide - https://art-of-lockpicking.com/how-to-pick-a-lock-guide/

 

[Baddegg]

Time to embark on your new hobby ...
How to Pick a Lock: The Absolute Beginner's Guide - https://art-of-lockpicking.com/how-to-pick-a-lock-guide/

Hope that’s not a step by step guide archy...

 

[static zap]

Hope that’s not a step by step guide archy...

..Only applies to Lectrics..!!

 

[Wilko]

Hi @enpassant just to while a few minutes away while you are there candle in hand awaiting succour, En Passant, I am teaching my grandsons chess and was trying to remember exactly how the En Passant rule worked, do you know?

My chess skills are so basic I had to ooogle that up. But if anyone tried that stuff on me I'd definitely have to resort to harsh language...

 

[buzzlightyear]

either its check or check mate for the op ,no lecky .

 

[Deleted member 105166]

hopefully he has power restored now, as a day has elapsed!

 

[Risteard]

Hi @enpassant just to while a few minutes away while you are there candle in hand awaiting succour, En Passant, I am teaching my grandsons chess and was trying to remember exactly how the En Passant rule worked, do you know?

I used to use the en passant move as it's surprisingly poorly known and understood. Unfortunately I can't recall the exact details of when it can be used so don't want to advise incorrectly, but from memory a pawn moves diagonally and captures an adjacent piece which in a square which it never occupies.

 

[Deleted member 26818]

If your pawn is on the 5th rank, and your opponent moves their pawn 2 spaces so it is alongside your pawn. You can on the next move take that pawn with your pawn as is if it had only moved 1 space.

 

[Rpa07]

T’is a great game, Chess, though not so when your nephew beats you when he’s 6 years old! Still, he’s working in Tesco now so I guess he’s the pawn!
(I love him very much by the way)

 

[The Ghost]

Yes that does sound right, on the fifth rank and the opponent moves his pawn, I remembered it was something like that but thanks @spinlondon

 

[enpassant]

Cheers for the replies guys.

Expect his batteries gone flat by now.

Yep. I used a battery pack to charge it but you guessed it... I hadn't charged that so it died too, without fully charging my phone.

Time to embark on your new hobby ...
How to Pick a Lock: The Absolute Beginner's Guide - https://art-of-lockpicking.com/how-to-pick-a-lock-guide/

Haha, thanks. Might need to try it next time.

Hi @enpassant just to while a few minutes away while you are there candle in hand awaiting succour, En Passant, I am teaching my grandsons chess and was trying to remember exactly how the En Passant rule worked, do you know?

Seems there's some interest in the thread as it's turned into a chess thread instead

en passant is French for in passing, it's a basic move, applicable only for the first move of a pawn.

If your pawn is moving towards enemy lines (5th, as someone else mentioned) then your opponent moves their pawn 2 spaces (only applicable if it's that pawns first move) from the 7th to the 5th, it's now adjacent to you - "preventing" you from capturing it like if it had move a single space.

En passant allows you to capture the pawn by moving to the space the pawn would have taken, if it had moved a single space instead.

 

[enpassant]

either its check or check mate for the op ,no lecky .

Bravo!

Electrician came out and went down to the locked cupboard, presumably the meters for the block and voila, power again.

Wasn't overly confident in him, weird character and I think English was his third or fourth language!

Opened up the box, took a picture in his phone and out it back together again.

Everything was fine again, had power yesterday then wake up this morning and the same 2 CB's are tripped as before, but not the full flat this time. So, lights and "sockets B", with the fridge and boiler off again. This time whilst we were asleep, but can see outside its been raining last night so again, I'm thinking maybe the boiler and somehow water is coming down the flue???

 

[buzzlightyear]

Any why ,after you move the prawns round the chess board and the king waiting for is sandwich.
did the queen have her hair drier on now when the electrcty when on .

 

[buzzlightyear]

Wasn't overly confident in him, weird character and I think English was his third or fourth language!

was it emperor of europe by any chance .

 

[telectrix]

Bravo!

Electrician came out and went down to the locked cupboard, presumably the meters for the block and voila, power again.

Wasn't overly confident in him, weird character and I think English was his third or fourth language!

Opened up the box, took a picture in his phone and out it back together again.

Everything was fine again, had power yesterday then wake up this morning and the same 2 CB's are tripped as before, but not the full flat this time. So, lights and "sockets B", with the fridge and boiler off again. This time whilst we were asleep, but can see outside its been raining last night so again, I'm thinking maybe the boiler and somehow water is coming down the flue???

so what tripped last nite? was it in the flat or in the meter box?

 

[The Ghost]

Well of course that is the issue, what made the main fuse go and not the local fuse first. Something is wrong there as we are required to design circuits that are selective in order of distance upstream/downstream so the local protection should go first. This is where you need an electrician to investigate and remedy that problem.

 

[enpassant]

Telectrix, the same two breakers as in the picture I attached to the OP - at the box, in the flat. It's lights and "circuits B" (not "sockets B" as I wrote in my last post.)

Not sure exactly what "circuits B" includes, but seems to be the boiler and fridge and not the cooker.

Well of course that is the issue, what made the main fuse go and not the local fuse first. Something is wrong there as we are required to design circuits that are selective in order of distance upstream/downstream so the local protection should go first. This is where you need an electrician to investigate and remedy that problem.

On the first night, yeah, but last night the local has tripped as it's at the box in the flat.

It seems strange to me that both the "circuit B" and lights go, but just one or the other?

 

[telectrix]

hangon.. is it the 2 MCBs that tripped, or the RCD ( next to them, with the yellow test button)? if it was that, it could be that the upstream fuse/MCB tripping could have caused that the first time round.

 

[buzzlightyear]

On the first night, yeah, but last night the local has tripped as it's at the box in the flat.

It seems strange to me that both the "circuit B" and lights go, but just one or the other?

will we get to the bottom of this .

 

[Andrew B]

I bet you they have a primary distribution board feeding all the flats, and that it has a 30mA RCD or RCBO protecting the flat.
Something in the lighting circuit of your flat has a ground fault which is causing both your RCD and the upstream RCD at the primary distribution board to trip.

Next time they reset the supply press your RCD test button, I bet it will cause the whole flat to go dead.
If that is the case all you need to do is find the ground fault in your lighting circuit.

 

[Strima]

I bet you they have a primary distribution board feeding all the flats, and that it has a 30mA RCD or RCBO protecting the flat.
Something in the lighting circuit of your flat has a ground fault which is causing both your RCD and the upstream RCD at the primary distribution board to trip.

Next time they reset the supply press your RCD test button, I bet it will cause the whole flat to go dead.
If that is the case all you need to do is find the ground fault in your lighting circuit.

That would be an extremely poor design if they had placed one 30mA RCD covering the whole flat supply in a locked cupboard.

 

[Andrew B]

Not really, electrician wouldnt know it will be locked...
And the electrician that did this CU assumed it was a standard residential install, he probably didn't have access too or knowledge off the upstream RCD at the main distribution panel.
Although I'd question how he could have tested his RCDs without finding out about the upstream one.
Or the primary distribution board was altered after the flats were built to add RCD protection - not realising the flats already had this covered.

This happens more than you would think. At my site we have two 30mA RCDs and a 10mA RCD on the socket. A test of the 10mA will trip all three!

 

[Strima]

Not really, electrician wouldnt know it will be locked...
And the electrician that did this CU assumed it was a standard residential install, he probably didn't have access too or knowledge off the upstream RCD at the main distribution panel.
Although I'd question how he could have tested his RCDs without finding out about the upstream one.
Or the primary distribution board was altered after the flats were built to add RCD protection - not realising the flats already had this covered.

This happens more than you would think. At my site we have two 30mA RCDs and a 10mA RCD on the socket. A test of the 10mA will trip all three!

Then the installing electrician must have either been blind or a complete ----wit. Basic electrical design takes discrimination between devices into consideration.

10mA RCD on the socket sounds very much like an American set up?

 

[Andrew B]

Yes American company, they haven't worked out we use a higher voltage so should expect higher leakage current!

 

[Strima]

Yes American company, they haven't worked out we use a higher voltage so should expect higher leakage current!

So they installed to American standards and not British standards?

 

[Andrew B]

Strima, out of interest what would you have done differently? If you turned up to fit a CU in a flat which included circuits needing protection - but suspected an upstream 30mA RCD in a locked area which you and the resident didn't have access too.

I suspect most would just get on with the job and fit the CU with RCD as they can't verify the upstream RCD. Doesn't make it unsafe just more likely to be inconvenient when it does trip - as the OP is finding out

 

[Andrew B]

Actually British standards do now cover 10mA RCDs. They are hard to find and expensive but they are there.

A few years ago however we were having to import American inline RCDs ...which were only rated for 115Vac ... We tried to explain how stupid that was. They would get quite warm under continued use.

 

[Strima]

I would have consulted the building owner to confirm the supply perameters and also the isolation point for the flat supply. Are you saying the spark swapped the flat DB over whilst the supply cables were live?

 

[Deleted member 26818]

I’ve used 10mA RCD sockets in the UK before now.