ProDave Posted December 24, 2021 Share Posted December 24, 2021 A multimeter won't do the insulation test. It will do a resistance check to determine the heater power. Follow the two black wires from the heater, they will end up at some of the terminal blocks a bit like the compressor motor cable you have already identified. Put the meter on the 200K ohm range and measure the resistance between the 2 black wires you have just followed to the terminal blocks. There is little doubt the heater is what is tripping the rcd so I would just be looking to replace it. But if you want to try rejuvenating it, I would be looking to undo the big jubilee clip, and remove the heater completely and take it into the house and put it somewhere warm for several days to thoroughly dry it out. Link to comment Share on other sites More sharing options...
Chriswills Posted December 24, 2021 Author Share Posted December 24, 2021 4 minutes ago, ProDave said: A multimeter won't do the insulation test. It will do a resistance check to determine the heater power. Follow the two black wires from the heater, they will end up at some of the terminal blocks a bit like the compressor motor cable you have already identified. Put the meter on the 200K ohm range and measure the resistance between the 2 black wires you have just followed to the terminal blocks. There is little doubt the heater is what is tripping the rcd so I would just be looking to replace it. But if you want to try rejuvenating it, I would be looking to undo the big jubilee clip, and remove the heater completely and take it into the house and put it somewhere warm for several days to thoroughly dry it out. Thanks Dave, thats what I will do next (when the rain decides to stop!) So if I disconnect the heater and refit the relay KA6/2, switch the unit on.......it should not trip? Link to comment Share on other sites More sharing options...
ProDave Posted December 24, 2021 Share Posted December 24, 2021 12 minutes ago, Chriswills said: Thanks Dave, thats what I will do next (when the rain decides to stop!) So if I disconnect the heater and refit the relay KA6/2, switch the unit on.......it should not trip? Yes if it does not trip with the relay back and the heater removed that should prove beyond doubt you have found the fault. Then we can concentrate on finding a new heater or fixing the one you have. 1 Link to comment Share on other sites More sharing options...
Radian Posted December 24, 2021 Share Posted December 24, 2021 Another KA6 shown `on the schematic powers a green light (compressor on) but it doesn't differentiate between KA6/1 or KA6/ 2. So far as I can see, three KA6 contact pairs separately switch on A5 (compressor starter), GN1 (green compressor on light) and R1 (crankcase heater) KA6/1 has been left in so that must have the compressor starter on it. KA6/2 has been removed and we know it connects the faulty heater. If the green light also comes on with the compressor then that will be on KA6/1 if not then its on KA6/1. Link to comment Share on other sites More sharing options...
Chriswills Posted December 24, 2021 Author Share Posted December 24, 2021 So I followed the wires from the heater to the source, which was on a plug as shown in picture (also had another feed in there), re-connected the relay /2 and it tripped immediately. Also tested the resistance as instructed and had a reading of 0.08. This was tested on the plug as shown in picture - disconnected. Link to comment Share on other sites More sharing options...
ProDave Posted December 24, 2021 Share Posted December 24, 2021 Are you saying it tripped when you put the relay back WITH that plug disconnected? If so, we have not solved this yet and this is where, due to the ambiguity on the circuit diagram, to start physically following the wired from the relay through the trunking to see where they actually go to. Link to comment Share on other sites More sharing options...
Chriswills Posted December 24, 2021 Author Share Posted December 24, 2021 22 minutes ago, ProDave said: Are you saying it tripped when you put the relay back WITH that plug disconnected? If so, we have not solved this yet and this is where, due to the ambiguity on the circuit diagram, to start physically following the wired from the relay through the trunking to see where they actually go to. Yes Dave, I put the relay back with the plug as shown in the picture.....disconnected. Ill try again to route the orange cable, but its very difficult a its buried in the loom. What do you think about the resistance reading? Link to comment Share on other sites More sharing options...
Radian Posted December 24, 2021 Share Posted December 24, 2021 Did that plug go into a socket labelled D ? Link to comment Share on other sites More sharing options...
ProDave Posted December 24, 2021 Share Posted December 24, 2021 I think, according to the circuit diagram, R1 (the one we thought was the problem) and R5 share the connector "D" can you confirm that one is the one you unplugged? Looking again at the diagram, R1 is energised when the compressor is OFF presumably to keep a bit of background heat in it. We need to find what is connected to the normally open contact of KA6/1. The diagram does not help us as it does not make any distinction between KA6/1 and KA6/2 So looking for NO contacts on "KA6" one feeds the compressor, and one feeds a light that is connected via terminals 8 and 9. Can you clearly identify any of the terminal blocks as being labelled as 8 and 9? If so try removing the cables from one side of each and try again with KA6/2 plugged in? EDIT the terminals 8 an 9 I am looking for are on the "Installer terminal block" not any internal terminal block. Link to comment Share on other sites More sharing options...
Radian Posted December 24, 2021 Share Posted December 24, 2021 (edited) @ProDave I think he's pulled out connector D - pins 1,2,3 go to R1 and 4,5,6 go to R5 It's looking like the IR breakdown is on the wiring going between KA6/2 and the mating socket D - probably the orange wire, as the R5 connections are switched by KA4 which is still in circuit without fault. Edit: crossover post missed your comment - so we're both thinking the green light? Edited December 24, 2021 by Radian Link to comment Share on other sites More sharing options...
Chriswills Posted December 24, 2021 Author Share Posted December 24, 2021 34 minutes ago, Radian said: Did that plug go into a socket labelled D ? I think it was D, cant be 100%, so will need to check Link to comment Share on other sites More sharing options...
ProDave Posted December 24, 2021 Share Posted December 24, 2021 It's definitely that orange wire, that's why I suggested physically following it through the trunking, you might even find where it is pinched or damaged doing that. My suggestion was to eliminate the "external" wiring to the lamp as the cause. Yes I am thinking green light. If the compressor is running and it's working it can't be that. If the light is on the outside of the case, UV damage could have cracked the plastic and water got in? just a guess. Link to comment Share on other sites More sharing options...
Chriswills Posted December 24, 2021 Author Share Posted December 24, 2021 I will check ASAP again the location of the orange wire. So.....this green light......where is it located? Link to comment Share on other sites More sharing options...
Radian Posted December 24, 2021 Share Posted December 24, 2021 The green light is labelled as "ON compressore" I also wonder where it's located! Link to comment Share on other sites More sharing options...
Chriswills Posted January 7, 2022 Author Share Posted January 7, 2022 (edited) Sorry I have not posted replies in a while. Removed the covers on the unit again this morning.....here is my findings: 1. To confirm.... the heater is connected to the socket labelled D, its the one I unplugged but still tripped. 2. Very difficult to find the orange wire location but on closer inspection, I do think it goes into KA5 as shown...would this be correct? There is no other orange wires on the the system. The KA5 orange wire (see pic) does have a little wear on it....maybe got damp? 3. The heater band is hot to touch on start up so seems to be working OK. 4. I have plugged KA6/2 back in this morning and it all starts up OK and does not trip...so far anyway.... Edited January 7, 2022 by Chriswills Picture uploads Link to comment Share on other sites More sharing options...
TonyT Posted January 7, 2022 Share Posted January 7, 2022 Turn the power off and tighten every screw terminal, relay terminal, din rail terminal etc to remove the probability of a intermittent cable fault. Link to comment Share on other sites More sharing options...
Radian Posted January 7, 2022 Share Posted January 7, 2022 No news on the "green light"? There seem to be three contacts (orange dots below) for KA6 but there are two KA6 and we don't know for sure which are feeding the circuit that trips. By unplugging connector D (green below) you've isolated the heater but it still trips so we shifted our attention to the remaining K6 circuit - the green light. This seems to be connected via the Installer terminal block but may not be fitted. However, terminals 8 & 9 in the terminal block is where its wires would go. See if you can identify any issues there. Link to comment Share on other sites More sharing options...
Chriswills Posted January 7, 2022 Author Share Posted January 7, 2022 No I cant find the green light. Do you mean the connectors in the block 8 and 9 shown in attached? I have the KA6/2 re-fitted from this morning and is still working but maybe a fluke? Link to comment Share on other sites More sharing options...
Radian Posted January 7, 2022 Share Posted January 7, 2022 9 minutes ago, Chriswills said: Do you mean the connectors in the block 8 and 9 shown in attached? Very likely - especially if 12/13 14/15 and 16/17 are all red link wires (can't quite see off edge of photo). If so there are no lamps connected and the mystery remains. Link to comment Share on other sites More sharing options...
Chriswills Posted January 7, 2022 Author Share Posted January 7, 2022 38 minutes ago, Radian said: Very likely - especially if 12/13 14/15 and 16/17 are all red link wires (can't quite see off edge of photo). If so there are no lamps connected and the mystery remains. Yes they are link wires, what about the x4 orange wires at the top? Link to comment Share on other sites More sharing options...
Radian Posted January 7, 2022 Share Posted January 7, 2022 1 hour ago, Chriswills said: Yes they are link wires, what about the x4 orange wires at the top? I think you would find they're the ends of the wires you can see on the terminals of relay KA6/2 and KA5 They basically go nowhere. Link to comment Share on other sites More sharing options...
Chriswills Posted January 8, 2022 Author Share Posted January 8, 2022 I just want to throw another question in here....I have an opportunity to have a new pump fitted for about 8K (tbc pending survey) with an RHI of £10,800 over 7 years. Now that I have had a few faults with this, would it be worth just selling this and having a new one with a 7yr guarantee too? Could I sell this one and for how much? Link to comment Share on other sites More sharing options...
ProDave Posted January 8, 2022 Share Posted January 8, 2022 9 minutes ago, Chriswills said: I just want to throw another question in here....I have an opportunity to have a new pump fitted for about 8K (tbc pending survey) with an RHI of £10,800 over 7 years. Now that I have had a few faults with this, would it be worth just selling this and having a new one with a 7yr guarantee too? Could I sell this one and for how much? If you really can get a new one fitted for £8K AND get £10.8K in RHI payments then it would be wise to do that, but you have to be quick because the RHI scheme is ending soon. the old one would not be worth much, it's the sort of thing someone might buy cheap to heat a garden room for instance? Link to comment Share on other sites More sharing options...
Chriswills Posted January 9, 2022 Author Share Posted January 9, 2022 Everything now working ok with the relay installed again. Just can’t understand why? Link to comment Share on other sites More sharing options...
TonyT Posted January 9, 2022 Share Posted January 9, 2022 Slack terminals? condensation inside RCD enclosure? tired and old Wylex RCD? Link to comment Share on other sites More sharing options...
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