I are "chuffed"
Apr 19, 2018 9:03:03 GMT
Post by tyrednexited on Apr 19, 2018 9:03:03 GMT
I are "chuffed".
I get an inordinate amount of pleasure travelling around on the bus using my (free) old-aged perisher's pass. (I know - there is something not quite right about me
). I could quite easily afford the bus-fares that it avoids, but, like many, if I were paying, I'd probably use the car. I had a day out by bus around the Cotswolds from Cirencester on Tuesday, and thoroughly enjoyed it.
However, even the level of "chuffedness" achieved was far surpassed by an exchange of eMails with an old work colleague.
Back at the end of October he'd got in touch with me to see if I could help with a problem. He wanted to lay-up hismotorcaravan motorhome campervan for the winter, and leave it plugged into mains in order to keep his batteries topped-up.
His problem was an odd one. His fridge had been overcooling in on-site use. In addition, he discovered when he got home that, even with everything fridge-related ostensibly turned off, it would still run (and overcool) if he hooked up!
The model of fridge he has is one that can be manually controlled, but also has expensive electronics installed that will (if allowed) automatically choose the most appropriate power source (12V, mains, gas, solar) depending on conditions and availability.
Cutting a long story short, the 12V circuit was eliminated (he was under the impression that he was also losing battery capacity and suspected the 12V circuit might be permanently in use - but I found no evidence to support it.). The battery charger and fridge were on the same MCB, so there no chance of isolating the feed to the fridge there (at least whilst still maintaining 230V input for battery-charging) so I disconnected the 230V feed to the fridge at the back. The fridge then stopped cooling, confirming a 230V issue.
The fridge was then run off the leisure battery in what is termed "emergency" mode. (it normally only works this way with the engine running, but it can be overriden on this 'van). Everything worked fine, with no overcooling, confirming the thermostat was OK.
At that point I was defeated, though the issue pointed to a control PCB issue (and this is not uncommon with this type of fridge). Having resolved his immediate problem by physically isolating the fridge, I went home (and continued to go at the issue like a dog with a bone).
Schematics showed that the 230V supply enters the complex PCB, goes immediately through a 12V/240V relay, and immediately exits again. The rest of the PCB (as far as 230V operation is concerned) is simply 12V circuitry for source selection and thermostat sensing, which then switches the 230V relay as and when 230V cooling is required/requested. The relay is a "normally off" model, and, after much thought, the only possible conclusion I could come to was a 230V relay which was stuck "on".
A replacement PCB is extremely expensive (£200 if you're prepared to risk eBay, and more if you use an authorised supplier). From photos of similar PCBs; I identified the relay part number (and checked the spec was consistent); it was available at under £5 delivered, and is fairly clearly "spaced" on the PCB. I recommended that my friend extracted the PCB (fiddly but entirely possible, we'd already nearly done it, and a full replacement would require that to be done) remove and replace the relay (6-pins to unsolder/ resolder) and re-install and test.
Of course, there might have been other problems on the board (but it shares much of the function between 12V - which was working fine - and 230V, so it was worth a punt).
Between October and last week he'd been struggling with a bad hip, but with the weather improving, he set out to try the fix. With the PCB out, (and after I'd told him to strip the fridge-manufacturer's paper part number off the relay to get the OE number) the part number was different to that I'd identified, but was a similar unit, and readily available at under £5. Over the weekend, and whilst I was in Cirencester, he got a local guy who does PCB repairs to simply replace the relay for a fiver, (desoldering is a pig without a desoldering pump, though there are alternatives), and then he re-installed the PCB to the fridge.
It has worked perfectly since - total cost under £10, and a bit of running round (as opposed to c£220 for a replacement, plus possible labour!).
I are "chuffed" (and it's not even my 'fridge - or £200). Just goes to show that the grey matter hasn't entirely disappeared yet.
(He's now thrown another issue at me which I think I might have identified at first try!).
I get an inordinate amount of pleasure travelling around on the bus using my (free) old-aged perisher's pass. (I know - there is something not quite right about me
). I could quite easily afford the bus-fares that it avoids, but, like many, if I were paying, I'd probably use the car. I had a day out by bus around the Cotswolds from Cirencester on Tuesday, and thoroughly enjoyed it.However, even the level of "chuffedness" achieved was far surpassed by an exchange of eMails with an old work colleague.
Back at the end of October he'd got in touch with me to see if I could help with a problem. He wanted to lay-up his
His problem was an odd one. His fridge had been overcooling in on-site use. In addition, he discovered when he got home that, even with everything fridge-related ostensibly turned off, it would still run (and overcool) if he hooked up!
The model of fridge he has is one that can be manually controlled, but also has expensive electronics installed that will (if allowed) automatically choose the most appropriate power source (12V, mains, gas, solar) depending on conditions and availability.
Cutting a long story short, the 12V circuit was eliminated (he was under the impression that he was also losing battery capacity and suspected the 12V circuit might be permanently in use - but I found no evidence to support it.). The battery charger and fridge were on the same MCB, so there no chance of isolating the feed to the fridge there (at least whilst still maintaining 230V input for battery-charging) so I disconnected the 230V feed to the fridge at the back. The fridge then stopped cooling, confirming a 230V issue.
The fridge was then run off the leisure battery in what is termed "emergency" mode. (it normally only works this way with the engine running, but it can be overriden on this 'van). Everything worked fine, with no overcooling, confirming the thermostat was OK.
At that point I was defeated, though the issue pointed to a control PCB issue (and this is not uncommon with this type of fridge). Having resolved his immediate problem by physically isolating the fridge, I went home (and continued to go at the issue like a dog with a bone).
Schematics showed that the 230V supply enters the complex PCB, goes immediately through a 12V/240V relay, and immediately exits again. The rest of the PCB (as far as 230V operation is concerned) is simply 12V circuitry for source selection and thermostat sensing, which then switches the 230V relay as and when 230V cooling is required/requested. The relay is a "normally off" model, and, after much thought, the only possible conclusion I could come to was a 230V relay which was stuck "on".
A replacement PCB is extremely expensive (£200 if you're prepared to risk eBay, and more if you use an authorised supplier). From photos of similar PCBs; I identified the relay part number (and checked the spec was consistent); it was available at under £5 delivered, and is fairly clearly "spaced" on the PCB. I recommended that my friend extracted the PCB (fiddly but entirely possible, we'd already nearly done it, and a full replacement would require that to be done) remove and replace the relay (6-pins to unsolder/ resolder) and re-install and test.
Of course, there might have been other problems on the board (but it shares much of the function between 12V - which was working fine - and 230V, so it was worth a punt).
Between October and last week he'd been struggling with a bad hip, but with the weather improving, he set out to try the fix. With the PCB out, (and after I'd told him to strip the fridge-manufacturer's paper part number off the relay to get the OE number) the part number was different to that I'd identified, but was a similar unit, and readily available at under £5. Over the weekend, and whilst I was in Cirencester, he got a local guy who does PCB repairs to simply replace the relay for a fiver, (desoldering is a pig without a desoldering pump, though there are alternatives), and then he re-installed the PCB to the fridge.
It has worked perfectly since - total cost under £10, and a bit of running round (as opposed to c£220 for a replacement, plus possible labour!).
I are "chuffed" (and it's not even my 'fridge - or £200). Just goes to show that the grey matter hasn't entirely disappeared yet.
(He's now thrown another issue at me which I think I might have identified at first try!).
