Heat Pump Earth Fault/Leakage

[binky]

on a TT system you have to have an RCD, but that could be upto 500mA unit for a single cct serving a fixed appliance - not sure if that is still correct under recent regs changes, I'm sure someone will correct me if I'm wrong?  :^O  .

Certainly a motor rated RCd would almost certainly help. As for melting cpc (earth) that would depend on the current through the cpc, which should be minimal.

 

[DeeJunFan]

on a TT system you have to have an RCD, but that could be upto 500mA unit for a single cct serving a fixed appliance - not sure if that is still correct under recent regs changes, I'm sure someone will correct me if I'm wrong?  :^O  .

Certainly a motor rated RCd would almost certainly help. As for melting cpc (earth) that would depend on the current through the cpc, which should be minimal.

The spark only had a voltage meter to test so i have no idea of the amperage 

The heat pump guy said we could use a 100mA RCD but spark wasn't happy to change anything.  He has just decided that the unit is faulty and wont touch anything else. 

 

[ProDave]

This just reinforces what I have been saying. You have a dud sparky.  You cannot diagnose and find an earth leakage fault with only a volt meter, and if you only have a volt meter you are not equipped as a proper electrician.

I do hope you find someone competent soon.

 

[Murdoch]

This is BS 

Edited this for you Dave

 

[DeeJunFan]

Thanks @ProDave  David Came out and ran a few tests on the unit. 

Everything looked good at the start he resistance tested the compressor and fan motor and a few other components on the board and all look ok. 

He then started the insulation test and put some voltage into the compressor,  he then retested the resistence and the it was dropped away to nothing so looks like a compressor issue. 

 

[Marvo]

Obviously moisture in the isolator could cause earth leakage problems but occasionally you get internal moisture problems with refrigeration systems.

All refrigeration systems should be moisture free internally and with colder refrigeration systems such as cold-rooms or freezers parts of the refrigeration system on the low pressure side runs well under freezing point and if there's even a small amount of moisture in the system it freezes and causes blockages.

With air conditioners it's possible to have moisture in the refrigeration system that goes unnoticed because the evaporation temperatures are usually a few degrees above zero Celsius so the moisture can migrate around the system without freezing and causing blockages. If there is moisture it can cause low insulation with the compressor windings as well as damage to the compressor valves.

With moisture problems, replacing the compressor will only maybe improve the leakage problem because the oil in the compressor that's being removed is hygroscopic and will contain at least some of the moisture that's causing the problem. There may however still be enough moisture elsewhere in the system for the problem to reoccur at a later date.

Before replacing the compressor I'd suggest your contractor should pull a deep vacuum on the system for at least several hours and repeat the electrical tests. If the test results improve significantly he should replace the filter/dryer and regas the system.

Locked to prevent being resurrected (again)