How many amps would this heat pump draw?

JohnW2 said:
Is there actually a sticker which says "100A fuse" stuck onto the holder?
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... i.e. something like this ...

1722355449545.png
 
I must admit the instructions are rather poor, 32 amps is clearly the size of the overload, the unit is unlikely to have much of an inrush, as inverter drive, but that is still 64 amps for the two units, which, if it is a 60 amp supply, means total supply to the house is for heating/cooling. Since 32A is a standard size for an overload, it is possible it does not use the full 32 amps. It says it has a 14.5 kW output, it seems likely the input is 3 to 5 times lower, depending on how efficient the unit is, so 12.6 to 21 amp, one would not run a 21 amp machine on a 20 amp MCB, and not all makes do a 25 amp, so seems likely the total is under 45 amps, but that is only a guess, so there seems only one option, ask the manufacturers.
 
specs.png


9.87A running current, 11.2A starting. Slightly less in cooling mode.
Two of them will only be around 20A, easily within the capacity of any normal house supply.

Unless the bungalow is vast and poorly insulated, 2 of those and 8 indoor units is very likely oversized.
 
My house is rather larger, and since improving the insulation and having CWI, the calculated heat loss at 0C outside, 20C inside, is 12kW..

Average winter gas usage is less. The boiler seldom exceeds 8kW.

It would be interesting to know the heat loss figures for @Custom45 home, to determine the power actually needed.

What is the existing boiler, and what size are the existing radiators?
 
JohnW2 said:
... i.e. something like this ...

View attachment 350702
Click to expand...
In my experience that sticker is quite rare and just a plain 100A fuse holder with whatever size fuse in it unless the seal is already broken (not that unusual) , I know one DNO in my area of work had a habit of "upgrading" any 100A fuses to 80A and using 16.0mm tails from cutout to their meter unless there was a prior arrangement to the contrary.
The other DNO (I more or less straddle the two DNO areas) had 60A to 100A in them and not usually changed.
If there have been substantial changes during the last 5 to 10 years with either DNO I have no idea, I am just speaking from personal experience.
 
ebee said:
In my experience that sticker is quite rare and just a plain 100A fuse holder with whatever size fuse in it ....
Click to expand...
Until quite recently, that would also have corresponded with my experience. However, at recent 'meter changes', the installations in both of the properties I own, and also those in most/all of those of my close family members, have acquired such stickers, so maybe there has been a change of practice/policy, at least for my DNO?

Kind Regards, John
 
I know my house has a 60 amp sticker, since when I moved in, the Wylex fuse box had a 60 amp isolator, it would have been silly to have fitted over a 60 amp rated fuse. Even today, with a 100 amp isolator, since the solar and the battery are connected after the DNO fuse, it would still be silly to change to a larger than 60 amp, I would need a second fuse between the consumer unit and supply, rated at 100 amp or less, before the DNO fuse could be changed to over 60 amp.

I can expect 5 kW from solar and 3 kW from the battery, so the consumer unit can have 35 amps over the DNO supply. Today peak export 4.7 kW. Using a heat pump to cool the house is no problem, if hot enough to need to cool the house, then solar production will also be high. Using it to heat the house, however, is another story.

I would love the system talked about here, I would want a non-electric stand-by, like an open fire for emergencies, but the system sounds great.
 
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