New Appliance 63Amp

[Woslights]

Dear All

I am having a heat pump installed and they say it needs a 63amp MCB, i only have a 100 Amp supply coming into the house, if i have the cooker, kettle, immersion heater etc on, will this cause a problem, ie will it blow the main trip/switch ?

 

[Pensdown]

You need to establish the actual running and start up current.

You will probably find that the actual running current is no where near 63amps.

 

[Steve]

If it needs a 63A protective device, you'll need to install a seperate enclosure, because I dont think they make them for domestic CU's.

I wouldn't expect a heat pump to use any more than 5kw though (20A). Thats a 20kw output!

You'll probably need to fit a C rated MCB though, which is more resistant to start up surges!

 

[ban-all-sheds]

Less resistant?

 

[toasty]

They do make 63amp MCBs that will fit in a normal DIN rail CU.
I know, 'cos I've got one in mine.

 

[Steve]

Apologies, oh mighty one.

less sensitive / more resistant.

 

[Steve]

They do make 63amp MCBs that will fit in a normal DIN rail CU.
I know, 'cos I've got one in mine.

Oh, what on earth for???

 

[Spark123]

They do make 63amp MCBs that will fit in a normal DIN rail CU.
I know, 'cos I've got one in mine.

They might make them for the industrial range, they'll probably fit in a standard range C/U but normal C/Us afaik are only meant to take up to a 50A MCB.

 

[AndyPRK]

wylex do a 63A AFAIK

 

[RF Lighting]

But their domestic CUs are not rated to take it...

 

[Stoday]

I'm surprised that the heat pump manufacturers are not using some sort of soft starting arrangement. The air source heat pump for my house uses an invertor to vary the output as well as make a soft start.

One of the conditions of supply is that you notify the DNO if you intend to increase your demand significantly.

A starting current getting on for 60 amps or more on a single phase domestic supply is going to cause voltage fluctuations. Unlike a shower or the like, the fluctuations will be frequent. There's a good chance these will lead to complaints and be unacceptable to the DNO. If so, you'll either have to disconnect your heat pump, pay the DNO to augment your supply capacity or fit a soft start arrangement.

 

[securespark]

http://www.gil-lec.co.uk/products/2823301365

 

[jason1958]

Does the heat pump actually require a 63A MCB?
- As in a 9-12kW air/ground source heat pump to water heating?

Or are they simply specifying 63A to avoid trip on startup inrush?
- As in a 5.4kW air source split load heat pump to air heating?


Sometimes heat pump makers suggest sky-high In rated Type-B to avoid nuisance tripping, rather than use a Type-C or Type-D device. So knowing what you are supplying may be useful.

 

[toasty]

They do make 63amp MCBs that will fit in a normal DIN rail CU.
I know, 'cos I've got one in mine.

Oh, what on earth for???

Low energy outside light!

No, just a small CU to protect a long run of T&E to the main one, a submain if you like. It's a contactum one IIRC

 

[securespark]

Just a quick note to mention that if you do use a type C or D device, make sure the EFLI is low enough!!