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Post by karlbrighton on Aug 12, 2014 12:11:25 GMT
Great forum! Thought this may interest. Have a BT GE Cj flat top. Think it's about 1937. Really lovely machine. Had this some time and looking forward to restoring fully. Having some problems. The thermostat wasn't working properly, have replaced with a ranco vc1, fits well and works fine, keeps good temp, though on a low setting. Runs for a few days without any problems, but then the compressor will keep running and overheat. Could this be the relay going bad? If I turn the temp to 0 compressor switches off. Any ideas. Will try and add some pics.
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Post by karlbrighton on Aug 12, 2014 12:26:40 GMT
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Post by coldspaces on Aug 12, 2014 13:22:33 GMT
Nice looking frig. I was just checking wring diagrams for the CJ models. It looks like most of them had the compressor overload built into the cold control. If that was the case with yours does your new Ranco control have an overload or did you add one? From what I goggled just now there is no overload in your new Ranco control.If there is no overload now you will easily damage the compressor if things are not right.
Does it really run till it over heats or is it sitting there and trying to start? Could be the start relay is part of the problem. If the contacts don't make connection it will just sit and hum till it trips the overload. If the contacts weld together it will keep the start winding on and draw to much power till the overload trips. Either condition will be bad for the windings if the overload is missing.
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Post by karlbrighton on Aug 12, 2014 16:28:48 GMT
Thanks for the reply. Are there available a compatible cold control with overload. Would like to replace, both the cold control and the relay switch. Don't know a lot on the subject, is this doable. Think it's a great fridge, so will do all I can. The compressor was working fine. Switching on for 2 mins at a time. Keeping good temp. Then didn't switch off. I could hear the gas bubbling around as before. Just not switching off. No difference in sound. The compressor always seems hot. But got really hot when it kept running. Fridge details. CJ-1-C16. Control M1A163 relay M1A162 1/8 HP. 2.2 - 4amp. Cheers Karl
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Post by karlbrighton on Aug 12, 2014 16:36:50 GMT
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Post by coldspaces on Aug 12, 2014 23:33:52 GMT
That sounds like your new control is sticking on. You need a watt meter hooked to it to relay know what its doing when it sticks on. That will tell you if it is still running normal. As far as I know there are no cold controls with overloads built in. You can get solid state relay and overload combinations that will work fine. They are easier to hooked up than a new mechanical relay and overload.The mechanical relay has a bit of an advantage as it will recycle instantly were a solid state relay has to cool off first. I was crazy enough to make a modern mechanical relay and overload fit in a type N and R relay housing. Looks like your is the less roomy type R housing. Its a fair amount of work but looks original when done.You can see the work here monitortop.freeforums.net/thread/37/ge-type-relay-modernization?page=1
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Post by cablehack on Aug 12, 2014 23:33:57 GMT
That's a nice Flatop. From your username, your fridge being a BTH, and by the looks of the radio sitting on top, am I right in thinking you're in the UK? If so, I'm curious what arrangements your fridge has for 240V operation. By the motor current specs and relay part number, the compressor appears to the U.S.A 110V type. According to the relay specs, yours is the type R with inbuilt overload that trips at 3.2A. If you replace it with something else you'll need an external overload protector. There is a mechanical relay you can substitute (Coldspaces is the expert on that), but you'll need a PTC overload protector to go with it. Some here use a combined PTC overload/start relay to replace the whole thing. If the compressor starts and runs normally it would seem your relay is OK. So, the control not shutting off is probably either because of a control fault, the thermostat capillary not making good contact to the evaporator, or because some refrigeration fault is not allowing the evaporator to get cold enough.
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Post by karlbrighton on Aug 13, 2014 18:52:26 GMT
Hey Guys.
Cheers for info, had a good look at the service manual on cablejacks site. Cheers for putting that on. Really helped to understand the operation, no nothing of fridges before. Really interesting, they were beautifully made machines!
It looks like the singe knob control that was on mine didnt seem have the overload in the control, but in the R relay switch. So hoping the VC1 control I used will be ok.
Coldspaces, had a look at the work you did to convert your original relay, amazed , way beyond my ability i think. Nice that it still looks original.
Are Mechanical relays still available? As it is hidden in the cabinet
Yep, am in the Uk on the Sussex coast. These BTH fridges are quite rare here, not many homes in 30's Britain had a fridge.
I run the fridge on a 1000w step down transformer.
It had an original 350VA in there, but that fried when I got her. as its upto 4 amp. running at around 2. maybe this indicates a problem with the relay? Not great with electrics. But learning!
Will check the capillary position. Reading the manual, it seems to be operating perfectly apart from when it's been on a few days, just continues running, really frosts up and the compressor gets roasting hot.
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Post by karlbrighton on Aug 13, 2014 18:55:18 GMT
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Post by coldspaces on Aug 13, 2014 22:19:03 GMT
If the R relay was sticking the motor would be tripping the overload rather than running non stop. The cold control is what cycles it on and off. Hope your new one isn't sticking.
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Post by cablehack on Aug 13, 2014 23:29:41 GMT
Thanks for the info on the transformer; can you take any pics of the original? I'm curious because in Australia the transformer was screwed underneath the cabinet on the DR and CK models. Neither of my CA's came with their original transformers, and there's no evidence of them being screwed to the cabinet, so I presume they must have been stand alone separate items. So, I have no information on them. The 350VA rating is about what I'd expect. It would provide a bit over 3A at 110V, but doesn't allow for any long term overload. I'm using a 500VA toroid with my CA-2 and a conventional type rated at 750VA for my CA-1.
It does sound like a control problem from the symptoms you describe. If the capillary is secured to the side of the evaporator, and the evaporator is frosting OK around where it's clamped, then my thoughts are something inside the control, or maybe even something wrong with where the bellows attach.
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Post by karlbrighton on Aug 14, 2014 20:49:45 GMT
Hey guys. Going to have a look at the cold control over the weekend. Check the capillary and put a meter on it. I really thought the relay was getting stuck on the on position. But you think this unlikely. Be great to save the original relay. Got a great click on off. Regards the transformer, I replaced the original with a 350va looks identical to the original. Just blue rather than the original black. Fixed to a square brackets on the base cross bar.
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Post by karlbrighton on Aug 14, 2014 21:23:37 GMT
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Post by cablehack on Aug 14, 2014 23:26:04 GMT
Thanks for the pics. The relay is only used for motor starting. The contacts make soon as power is applied, and when the motor has come up to speed the contacts open again, disconnecting the start winding which is no longer required. If it stuck on, the start winding would always be in circuit, which would cause excessive current draw and eventually burn out the winding. The overload protector is supposed to disconnect the motor if this fault should happen. You can open the box on the side of the compressor and watch the relay in action, but don't apply any pressure to the actual relay or it could be put out of calibration. If you are suspicious of excess current being drawn, I recommend a plug in power meter - this will give you a very good indication of how well your fridge is performing.
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Post by karlbrighton on Aug 17, 2014 16:15:31 GMT
Hey guys. Have checked the power with a power monitor. The service manual says that the average running amp on this model is 2.3amps. From starting up and running it stays around 3.9amp. Shouldn't it start at that then drop down. Sounds not good?
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