45A or 50A MCB for shower?

Hi,

I have a 9.8kW shower which I wish to install. It already has 10mm cable. The manual is quoting 45A breaker (9.8kW @ 230v, 9.0kW @ 240v), will the shower be ok operating on a 50A breaker? What are the potential risks with going higher than 45A?

Many thanks

Dave

Reply to
Dave
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Those figures sound like they are back to front...

9.8kW at 240V indicates a heater resistance of some 5.8 ohms, which on 230V would yield a power output of just over 9kW

It takes longer to operate in response to some types of fault condition. Also in may not adequately protect the internal wiring of the shower.

Reply to
John Rumm

John,

You are right. 9.8kW @ 240v, 9.0kW @ 230v. Doh!

45A type B star breakers seem to be hard to find. Crabtree don't seem to do one.

Dave

Reply to
Dave

A 40A one will be fine...

Reply to
John Rumm

Whats the rating of the switch and cable to the shower from the consumer unit?

Reply to
cynic

That is because they do not make them.

It will probably pack in after 20 years and need replacing, other than that it should be fine.

Adam

Reply to
ARWadsworth

"They" being Crabtree I take it?

MK do them:

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Reply to
John Rumm

The switch is rated @ 50A the cable is 10mm.

John, thanks for the link. I was going to put an order in with TLC, so the timing couldn't have been better.

Cheers

Dave

Reply to
Dave

Yes

Adam

Reply to
ARWadsworth

On 8 Mar 2007 00:02:16 -0800, "Dave" mused:

So what's the rating of the cable then?

Reply to
Lurch

The best case is about 63A when clipped direct, with no other derrating factors to include.

Reply to
John Rumm

On Thu, 08 Mar 2007 22:49:32 +0000, John Rumm mused:

I know that, but only the OP knows what the actual rating is.

Reply to
Lurch

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