Question about metering solutions.

I would use a conventional KWH meter as used on a domestic supply. Used mechanical meters or new digital electricity meters are available on fleabay.

Replace the existing socket outlet with a 13 amp fused connection unit. From fused connection unit into the KWH meter. Then from the meter and into a single non standard socket outlet such as a 15 amp pin socket or a 16 amp ceeform type.

Avoid a standard type 13 amp plug and socket for the metered supply due to risk of misuse, or suspicion of misuse. A non standard MK 13 amp socket could be used, in which case the earlier suggested upstream fused connection is not needed.

Double check that the ENTIRE consumption of the chiller is supplied via the 13 amp plug. Some walk in cold rooms have separate supplies for different components.

if there is room for a box with some DIN rail then one of these might do it.  Not much bigger than an MCB, they can be read remotely with a computer over an RS485 interface but generally pushing the buttons and squinting at the display seems to be preferred. Many clever programming modes available but best avoided. The small direct wired one, not the one that connects to an external current clamp. Also similar things made by Finder..

Not of course certified and sealed like a proper suppliers meter, but the price and security level of the DIN package reflects that. Depending how the charging is to be done, that may or may not matter.

Mike

Assuming that this supply comes from the Grid...

You might like to remind your client that there is a maximum price at which we can re-sell this electricity. He can't simply chose a price that he feels makes it a 'good little earner....'

A regular plug-in energy monitor sounds like the simplest solution to me - e.g. something like: https://www.screwfix.com/p/energenie-ener007-energy-saving-power-meter-socket/3477h

    - Andy.

I am surprised that a reasonable estimate would not simply be added to the rent. I don't think that a plug in meter would be secure enough.

As the fridge supply is on 24/7 while the client is in possession,Clamp the fridge supply with and without the compressor and take the average. Measure the Uo to gain the kVA, multiply by the number of client hours then apply kWhr rating for the property and charge accordingly. Or we could complicate it a little and run the whole process through a PLC and monitor it via some method of telemetry.

Just out of interest, its not anything to do with proving credability with the HMRC?

So far as I am aware, this only applies to electricity for DOMESTIC use, for a presumably not domestic cold room, charge what you want.

I can nor recommend use of a plug in energy monitor. Many are of doubtful accuracy, and most have no reliable memory, they reset after after a power cut or after any accidental or malicious interruption. 

Neither can I recommend any estimate based on short term measurement or observation, consumption will vary a lot according to ambient temperature, door opening, and temperature of goods placed into the store.

If you need to know how many kwh are used, fit a kwh meter. they are not expensive, nor hard to fit.

If you know the power consumption of the appliance which will run for 24/7 while the client is in residence then add the price of electricity onto the rental.

Is there a problem with that method?

Yes I can see a problem. It is not a constant load. In cool weather it might only run for a few minutes in each hour, possibly not at all in extreme cold weather.

In a heatwave it might run 24/7.

Also the power factor is unknown and might vary.