If my cellar were to flood?

[mattylad]

Hello, I have my electrical supply & CU in the cellar, I'm just wondering what is likely to happen should the cellar (below street level) flood to above the height of the CU?

Now I'm sure thatt here will be a big bang at some point, and that things will be in a bit of a mess.

But what happens about getting the supply turned off? is there likely to be some form of cut out at the local substation?

Will it be unsafe to go into the water?

What is likely to happen to the CU & wiring?

All hypothetical of course, but just something I'm wondering about.
BTW There is no way I can have it moved anywhere else.

 

[ban-all-sheds]

Will it be unsafe to go into the water?

Very unsafe indeed.

But not because of the electricity - if you think that what would be filling your cellar would be just water you're sadly deluded.

What is likely to happen to the CU & wiring?

The CU will fill with stuff that isn't just water.

All hypothetical of course, but just something I'm wondering about.

You need to get out more.

BTW There is no way I can have it moved anywhere else.

a) Why not?
b) Of course there is.
c) No point worrying about it then.
d) None of the above.
e) All of the above.

 

[Mike2007]

I may be totally wrong but I have seen incoming supplies moved on more than one occasion to a more "up to date" safe height!
Your layout would probably be fine, but as you say it could happen. Especially with our increasingly WET British climate!

 

[RF Lighting]

You might be amazed, but you installation may well carry on working whilst underwater.

See how the street furniture is still working despite being under water

 

[ban-all-sheds]

1) Were I designing equipment like that I'd consider a battery backed-up failsafe red pedestrian signal for powercuts.

2) Probably a bit of difference between underground cables running to something above the water and a domestic CU underwater.

 

[AMEdinburgh]

There's been quite a few flooded cellars here in Edinburgh over the past two days with the torrential rain, so it does happen.

If you have a cellar likely to flood, why not install an automatic submersible pump in the lowest point discharging to somewhere suitable.

Most cellar flooding is seepage though the walls due to a rise in water table which a decent pump will handle unless your near a watercourse that bursts it's banks in which case you're stuffed, sadly!

In that case you might be better spending your money on a dingy

 

[streetlighter]

Its quite common for illuminated bollard bases to get full of water durung heavy rainfall or if the gland entry hasnt been sealed properly.
And they still work fine with the cutout burning away under the water.

 

[ban-all-sheds]

I'd forgotten about those things.

Maybe the OP would still have power then. Assuming the "water" didn't allow enough fault current to flow to trip the RCD...

 

[mattylad]

OK, I cannot have the cables moved because there is nowhere else for the Cu to go.
Not unless the electric supplier is willing to extend the incoming cable to a new meter above street level & the chances of me paying for that are about as good as me getting a free ride to the moon.

While the RCD may trip, there will still be power from the meter, so the main incoming fuse may trip, but then water will still be shorting across the incoming feeds. So whats there to protect for that?
What happens if there is a short before the incoming fuses?
whats at the exchange for this?

WHile I realise that there may well be "other stuff" when I talk about flooding, I'm not talking about drains backing up & causing it, I live at the bottom of a hill so am thinking more of water flowing down there.
(not that it will ever happen, perhaps I do need to go to the pub instead? )

Could/would the water be like it is in the films/tv & electrified like dropping a hair dryer in the bath?

 

[NotHimAgain]

There is no evidence that dropping a hair dryer in the bath will do anything other than blowing the protective device - even if that. Mind you, it is difficult to get volunteers to test the theory.

However, when the Swiss were asked about deaths in bathrooms they declined to provide any data on the grounds that it might encourage suicides.

 

[ban-all-sheds]

BTW There is no way I am prepared to pay to have it moved anywhere else.

 

[Steve]

Submerge a mains junction box, and the current passing will only trip an RCD - there isnt major amounts of current involved. There will be no big bang. You probably wont get a shock if you go into the water since it is earthed anyway.

During the yorkshire floods last year, our crawlspace (cellar) flooded to just below the joists. There is a junction box on the concrete floor, that was submerged. All that happened is the RCD tripped. There was no bang. If it weren't for the RCD it would have carried on working.

 

[ban-all-sheds]

You probably wont get a shock if you go into the water since it is earthed anyway.

Nope.

Cholera, dysentery, typhoid, but not a shock.

 

[plugwash]

There is no evidence that dropping a hair dryer in the bath will do anything other than blowing the protective device - even if that. Mind you, it is difficult to get volunteers to test the theory.

I imagine it would depend heavilly on what the bath was made of, what stuff was earthed, how dirty the water was and what stuff the person in the bath was touching at the time.

 

[mattylad]

You seem to be saying the RCD will trip but forgetting about the supply itself, what about the incoming supply? thats at the same level ast the Cu & enters the CU just the same, I know the outgoing from the CU may stop.

Whats likely to happen with the supply? is it going to stay on & start shorting out through the water & cause problems with the incoming cable? at the substation etc?

Nasties in the water are not whats concerning me, I know there is going to be enough crap floating in there - lol
As for pumps etc, that may be in the overall plan eventually.