Compressor failure caused by wrong fuse

[brianshug]

On a new integral freezer, we have told the customer its 20amp rated. He's never upgraded it from the 13 amp plug top and now the compressor has failed. It hums on start up, pulls 25amps and blows the 13amp fuse. Has the 13amp fuse protection have anything to do with the compressor failure? My thinking is if it's blown while starting up, may be a factor. The units are very reliable, when on the right supply. and it's the customers electrician who has kept it on the plug top. Thanks for your help in advance

[martinw58]

i do not think fitting a 13 amp fuse will make the compressor fail

[thebigcheese]

sounds more like the compressor has seized, or else it has not equalised out and now cannot start against high head

[supra_84]

errrm, maybe the compressor wont hold in on a 13 amp fuse for start up reasons. maybe you should try a bigger fuse before comdeming the compressor.

[SeanB]

If it ran for a while with the 13A plug fuse in then I would blame the compressor, or the start components rather than the supply fuse. If it was supplied with a 13A plugtop and ran for a few days or weeks then it would not be the connection. Placing a 20A fuse in a 13A plugtop is not correct, and can lead to a fire. It hums on start up means the compressor is not starting, which points to either a faulty starting relay, a bad compressor, a faulty overload, or a faulty capacitor ( if it uses a start capacitor) rather than a fuse, which is doing what it is designed for and breaking a 25A current. That you are able to measure the current means that the fault is not in the fuse or selection of fuse rating, but in the unit itself.

If it was meant to be installed on a 32A dedicated outlet rather than a 13A mains is the fault of the installer, but that should not cause the unit to fail, unless the customer is able to change a plug fuse in seconds before the system pressures equalise.

[install monkey]

if it was originally installed on a 13a plug top then maybe the inertia of start up has weakened the fuse and caused it to blow well before its rated capacity. but better still megger the cabinet to prove no earth leakage,replace the fuse and clip the current to see if the compressor is siezed as you stated it keeps blowing fuses so the compressor will have failed

[nike123]

Fuse is element in electrical circuit designed to protect cables, wires, switches etc...and not compressor (or any other current consuming element). There are some special fast fuses for that task, but they are not there in your case.
Therefore, answer to your question is that fuse, you are referring to, is not cause for your compressor failure.

[cool runings]

On a new integral freezer, we have told the customer its 20amp rated. He's never upgraded it from the 13 amp plug top and now the compressor has failed. It hums on start up, pulls 25amps and blows the 13amp fuse. Has the 13amp fuse protection have anything to do with the compressor failure? My thinking is if it's blown while starting up, may be a factor. The units are very reliable, when on the right supply. and it's the customers electrician who has kept it on the plug top. Thanks for your help in advance

The 20 amp does not sound right.

In the UK an integral will be fitted with a domestic 13 amp plug top, if rated lower than 13 amps.
Above 13 amp they come fitted with the blue 16 amp fitting.

Integrals as far as I know in the UK do not need a 20 amp supply!!! (I might be wrong, it has been known).
How do you intend on wiring the thing up? Hard wired into a fused distribution board?

So in answer to your question could a domestic fuse cause the comp to fail, I would
say no because when the start amps goes above 13 amp for too long or too often then the fuse melts.

If the customer has been replacing fuses over a prolonged period of time that could
cause the comp problems I spose but chances are it is just a coincidence..

All the best

coolrunnings

.

[brianshug]

I'll try to be a bit clearer. The customer was supposed to supply a 20 amp supply to be hard wired. The unit is protected by its own fuses (16amp cartridge). The customer asked the electrician who advised the customer it doesn't need the recommended supply as its ran off the 13amp plug top for 4 months until now. We disagree and now the compressor has seized for the second time, with a new compressor lasting 1 month. My query is, in theory can a too low rated fuse damage the compressor? possible during start up.
We're not going back until the supply is sorted as per manufacturers recommendation, as we beleived the customer in good faith would of sorted out his power supply when told to do so, but who would you believe, an Electrician or fitter? The customer took his electrician's advice

[Segei]

I agree with nike 123. Fuses protect wiring. Compressor should be protected by overload.

[NoNickName]

My query is, in theory can a too low rated fuse damage the compressor?

No. A too HIGH rated fuse can damage the compressor.

[monkey spanners]

If the supply is undersized i wonder if there is low voltage problems during starting? this could damage the start electrics and lead to comp failure (if the relay doesn't drop out the start cap will fail very soon after), but you'd need to check the relay and caps, also it would be worth stripping the old comp to see what has failed in it.

[mikeref]

Maybe... compressor cycling too many times per hour. Thinking compressor might have pumped out it's oil and second compressor now doing the same.

[mad fridgie]

To small a fuse would not cause a compressor failure, to small a wire feeding the socket, may cause a volt drop, but would have to be pretty small, the only issue with using standard 13amp plug could be the contact area where plug meets the socket, causing low voltage, i think you would see charing on the plug pins, but personally the difference in amperage is minimal to cause this to happen."chunky pommy plugs"
I would look firstly at the ventilation around the fridge, is there any and is it sufficient

[Mark Selby]

quick answer is no lower rated fuse wont hurt a motor or comp...as far as start up amps prolly a slow blow fuse allowing for start up in rush