How To Check 24v With Multimeter Zone Controller

Old 07-26-05, 11:07 PM

Saga continues

I bought this handy great Fluke 16 multimeter pretty amazing little tool, now if I can just figure out how to use it hmmm. Also got a nice Fluke 334 for backup and piece of cake amp readings and picked up a Cooper SHR77a temp humidity thing with the clamp on temp probes. Replaced the transformer and contactor yesterday the unit ran for i day then started doing the same thing no condensor fan or compressor now I have figured out that the contactor is not pulling in and I am not getting 24 volts at the contactor. I am getting 24 volts out of the new transformer one wire feeds ane side of the contactor the other leg feeds downward to the control board it appears that the thermostat 24 volts feeds from the lath out then returns on the yellow wire on a call for cooling I have verified voltage to that point and unit starts (contactor pulls in) if I jumper from the yellowish wire from the thermostat to the contactor terminal This appears to be a control board problem simply I am hesitant to condemn it untill I get a wiring schematic, there has to be a high pressure switch and probably a time filibuster, one of these could be telling the board non to let the 24 volts thru to the contactor Right? I see a black box that could be a time delay, one leg of the 24v transformer feeds the post marked number ii information technology tees off and goes straight to the contactor from there. One post I could non see a number but presume information technology is #1 is a green wire that ties into the light-green wire from the thermostat #three post and #4 are jumpered together and announced to feed a blackness wire going to the blower motor I get 115 volts to ground off this #5 and #vi are a blue and a orange wire goig to god knows where, these have 115 volts each to basis and 240 volts betwixt them. I may merely pickup a time delay and popular on there to run across if that works, the contactor and transformer both together were less than 20 bucks and since the unit has been underwater it would probably exist a good affair to do. I think I will go a new capacitor also this one is real rusty. I found that if I smacked the board a chip it would go ahead and get-go then I am suspecting the fourth dimension delay relay now, although when you smack the side the board moves besides, it has to be one or the other doesn't it????????????????? Annotation I take pulled every connector off and checked for tightness no way this is a loose wire I spent two hours fooling with it this afternoon the silly thing is running like a new i at present but suspect that information technology will human activity upwardly over again. It started at least 6 times flawlessly hmmm Note it has a delay built in somewhere cause i was pulling the outside disconnect and it would take the compressor and condensor fan a total three minutes before they would restart. Dang I have typed here and totally convinced myself that the problem is the filibuster, I will try to get 1 tommorrow and install it. Human is this fun or what?

Source: https://www.doityourself.com/forum/air-conditioning-cooling-systems/224310-how-check-24v.html