ASHP tripping electric....HELP!!!

[Chriswills]

1 hour ago, ProDave said:

KA6 appears to be switching "R1" which might be a resistance heating element as well as the compressor.  The diagram does not tell us which is KA6-1 and which is KA6-2

 

Is there a parts list or anything else that says more about what R1 is?

 

Have you sat and listened to the unit while it is working?  You would know if the compressor is starting and stopping.

I have enclosed the complete manual, I assume as per the picture that KA6-1 is on the left hand side, and -2 to the right.

Compressor seems to be working and is warm to touch as are the pipes coming from it.

Hope you can find something in the manual Dave.

Air_source_MT_rev2.pdf

[Radian]

My previous post gave you the cause of the problem. The compressor is working but an internal heating element in the crankcase is faulty (R1).

Obviously replacing the compressor would clear the fault but may be unnecessary if the heating element Insulation Resistance can be restored.

Leaving relay KA6/2 permanently out of circuit will clear the fault but may compromise the operation of  the compressor in the long-term.

An electrician who has an insulation resistance checker could monitor the actual condition of the element and if not too much leakage current, could power the element in an attempt to dry out the moisture that's causing the breakdown. That would be my approach.

Edited December 22, 2021 by Radian

[Chriswills]

23 minutes ago, Radian said:

My previous post gave you the cause of the problem. The compressor is working but an internal heating element in the crankcase is faulty (R1).

Obviously replacing the compressor would clear the fault but may be unnecessary if the heating element Insulation Resistance can be restored.

Leaving relay KA6/2 permanently out of circuit will clear the fault but may compromise the operation of  the compressor in the long-term.

An electrician who has an insulation resistance checker could monitor the actual condition of the element and if not too much leakage current, could power the element in an attempt to dry out the moisture that's causing the breakdown. That would be my approach.

Thankyou looks like a way forward, can you tell me on the pictures I previously posted where the R1 is please?

[Radian]

8 minutes ago, Chriswills said:

Thankyou looks like a way forward, can you tell me on the pictures I previously posted where the R1 is please?

Inside the compressor housing - in the crankcase, as described in the schematic you posted.

[Chriswills]

5 minutes ago, Radian said:

Inside the compressor housing - in the crankcase, as described in the schematic you posted.

Thanks, would you be able to show it on the actual pictures I sent in of the unit, as an indication please?

[ProDave]

Just now, Chriswills said:

Thanks, would you be able to show it on the actual pictures I sent in of the unit, as an indication please?

I doubt we can do that. It will be 2 out of several connections to the compressor.  If you can post some more close up pictures of the compressor showing all the different connections going into it, then it might just be possible to identify it, if it happens to be on a separate connector, but it could well be all the connections go through one big multi pin connector.

 

If I were going to try energising R1 to try and dry it out, I would be attempting to make the connection for the temporary power at the unplugged relay.

[Radian]

18 hours ago, Chriswills said:

Am I looking for noise from here. Is this the compressor?

 

I'm guessing it's not a serviceable component, but contained inside the welded steel enclosure.

Any attempt to fix it would be conducted from the external wiring. The heater live and neutral would need to be identified and a temporary connection made to them ideally using an isolating transformer.

[ProDave]

2 minutes ago, Radian said:

The heater live and neutral would need to be identified and a temporary connection made to them ideally using an isolating transformer.

That test would enable you to determine the power of this heating element.  If it is low, it might be possible to just buy an isolating transformer to power it as a permanent fix.

[SteamyTea]

As not many companies make compressors, can it be identified.

Is there a part number on it?

Them maybe find some details about it on line.

 

Maybe here.

Edited December 22, 2021 by SteamyTea

[Radian]

10 minutes ago, ProDave said:

That test would enable you to determine the power of this heating element.  If it is low, it might be possible to just buy an isolating transformer to power it as a permanent fix.

Maybe, but I expect the reason for the IR breakdown is cyclic warming/cooling pulling a tiny amount of moisture laden air into  the housing - after all, unless there's a refrigerant leak, no actual fluids are present. If it's that marginal then powering the heater on for a day or so could restore it. Both KA6 relay coils are in parallel so the crankcase heater is designed to be energised all the while the compressor runs so should handle continuous energisation.

[Radian]

4 minutes ago, SteamyTea said:

As not many companies make compressors, can it be identified.

Is there a part number on it?

Them maybe find some details about it on line.

 

This doc from https://www.orionairsales.co.uk/ may be relevant but its a bit light on wiring detail

[dpmiller]

It's a hermetically-sealed compressor. Whilst the heater might indeed be inside the enclosure you might look on the underside of the black housing  for a stick-on silicone pad heater  with a couple of wires coming off it too.

[ProDave]

There looks to be a (probably plastic) terminal enclosure on the side of the compressor.  If you can get the lid off that and take a photo of what you see inside that might help.

[SteamyTea]

5 hours ago, ProDave said:

There looks to be a (probably plastic) terminal enclosure on the side of the compressor.  If you can get the lid off that and take a photo of what you see inside that might help.

Would it be worth putting an Ohm meter across the relay terminals and seeing what it reads.  If the resistance can be established, it may indicate what sort of heating element is there.  I would assume it is a fairly low powered one, 200W or something, so around 265 Ω

[Radian]

59 minutes ago, SteamyTea said:

Would it be worth putting an Ohm meter across the relay terminals and seeing what it reads.  If the resistance can be established, it may indicate what sort of heating element is there.  I would assume it is a fairly low powered one, 200W or something, so around 265 Ω

 

Would be interesting I agree. However, for fault finding how about @Chriswills  getting one of these

 

OK, so it's xmas cracker grade Chinese instrumentation but £43 not £1K for a proper megger.

I can vouch for the fact these usually do work well enough to predict if an RCD will trip or not.

[Chriswills]

On 22/12/2021 at 16:24, ProDave said:

There looks to be a (probably plastic) terminal enclosure on the side of the compressor.  If you can get the lid off that and take a photo of what you see inside that might help.

Heres the image of the removed plastic cap, where it connects to and whats inside the cap.....some instructions. I have not been able to find out where R1 is on the system or trace the orange lead, it dives into an area I cannot get to. 

These are the only electrical connections to the compressor.

[Chriswills]

[Radian]

I see you put up a photo of a piece of plastic mentioning the crankcase heater but it's not any of the wires in the previous photo. Where can it be?

[Chriswills]

1 minute ago, Radian said:

I see you put up a photo of a piece of plastic mentioning the crankcase heater but it's not any of the wires in the previous photo. Where can it be?

Its just the inside of the cap I removed on the compressor

[ProDave]

40 minutes ago, Chriswills said:

Heres the image of the removed plastic cap, where it connects to and whats inside the cap.....some instructions. I have not been able to find out where R1 is on the system or trace the orange lead, it dives into an area I cannot get to. 

These are the only electrical connections to the compressor.

That's the connection to the compressor motor.

 

So the connection to the heater will be somewhere else, almost certainly lower down on the compressor housing.  Can you find another similar terminal box lower down?  It will probably have just 2 wires and possibly an earth wire as well.

[Chriswills]

These are the only other x3 wires I can see going into the bottom of the compressor, x2 black and one earth. They fit into a large jubilee clip with a sort of tube attached around it. Is this the heater connections?

 

EDIT - after a bit of research I found this to be the crankcase heater

 

Edited December 24, 2021 by Chriswills

[Radian]

So if that's the heater and its insulation resistance is compromised what are you going to do? Personally, I would use an IR test meter to measure between each black wire and earth, make a note of the readings then power it up from a non-rcd protected supply, leave it a day then test again. If it doesn't show a higher resistance then there's not much hope and it could be a question of finding a spare. Or just leave it unconnected.

[ProDave]

Well that is GOOD news. The crankcase heater is a separate item strapped onto the outside of the compressor.  I would just seek out a replacement and fit a new one.  It does not need to be identical.  Measure the resistance (black wire to black wire) to get an idea of the power rating then any strap on heater of that power rating should do.

[SteamyTea]

6 minutes ago, ProDave said:

The crankcase heater is a separate item strapped onto the outside of the compressor

Would it be a temperature self regulating type?

[Chriswills]

So I have 2 questions:

 

1. If it is working OK, would it be hot to the touch (I read this) and when would it be hot?

2. I have a multimeter (never used one) can I have a step by step instruction on how to test the heater before buying a new one please?