View Full Version : thermostat wiring help
Im having trouble getting a thermostat working properly.
Normally to disconnect the thermostat on a r12 fridge compressor I put a link to where the thermostat use to go here.
So when I installed it I took the link out and put those 2 wires across the thermostat.
I then placed the end of the thermostat in the res (small amount) didn’t work.
I then moved the thermostat wire under insulation on the water lines going to a water block.
At -22c is not stitching off. Have I wired it correctly.
For the second pic, the red arrow is the thermostat. And the red line is where the thermostat probe is located under the insulation sensing the temperature.
The thermostat is out of an old fridge.
http://www.xtremesystems.org/forums/attachment.php?attachmentid=36617&stc=1
http://www.xtremesystems.org/forums/attachment.php?attachmentid=36618&stc=1
bump
sorry to be a pain, but im sure ppl have used a thermostat before.
Im dieing to finish this thing
hatemi
09-06-2005, 12:02 PM
I'm sure some of the techs can help ya on this one when they notice this thrad.
C-BuZz
09-06-2005, 12:53 PM
Hi Mate,
Dud thermostat mabye? I've got a few here if you want, but knowing you im sure you have many :)
Or I have a few fridges sitting outside, I can snap some pics of the wiring if you think it will help?
Just out of couriosity.. why would you switch it off? Unless you want to maintain a set temprature.. hmm am I answering my own questions again :D
C-BuZz
did you connect the wire of the thermostat to the middle pin of the compressor(i know there is a startingdevice on there but try to find it)
the 2 lines that starts above are connected in the startingdevice afaik
http://www.xtremesystems.org/forums/attachment.php?attachmentid=36672&stc=1
i hope this helps?:)
Golden_Eagle
09-06-2005, 01:17 PM
what would be the temp that makes the thermostat open the circuit?
-22 does he said above, i think its the switchoff temp:)
chilly1
09-06-2005, 05:38 PM
Could you remove the relay that is connected to teh two pins and post pictures of all four sides please.. with good lighting.. I need to get a better look at it...
Thanxs guys.
Chilly ill do that tonight.
did you connect the wire of the thermostat to the middle pin of the compressor(i know there is a startingdevice on there but try to find it)
the 2 lines that starts above are connected in the startingdevice afaik
i hope this helps?:)
thanxs for that jort. I think understand that drawing. Ill take pics tonight (closer ones ) and try and identifiy items to ya drawing.
golden eagle its just the standard thermostat like in ya fridge at home.
I know my fridge temps rang from like 10c to almost 0c positions to switch the cooling part on and off.
And the freezer stays around -15c to around -25c to memory (not sure exact figures).
Cbuzz basically I want a cooler that is capable of keeping water around 10c or as low as -20c would be good. So Which eva lucky person in my home town that buys it can set it to what ever temp they desire, 10c, 5c 0c -5 through to -20c. Have to get it to work first though.
Basically they turn the knob to get it to switch of a desired temp.
I know where there a few old fridges, so I can get more, just have to pick one out next time go ridding. I havnt found any compressors for abut a year though. Taken all the good ones (not rusted and not 100 years old).
wdrzal
09-06-2005, 08:58 PM
if you just what it to turn the compressor on and off all you need to do is break the L1 line. There is a issiue with short cycling, if the stat shuts down the compressor is must be off long enough to equilize pressure so it can restart.
if you just what it to turn the compressor on and off all you need to do is break the L1 line. There is a issiue with short cycling, if the stat shuts down the compressor is must be off long enough to equilize pressure so it can restart.
that was my tought too, i am making some chillers in the future too but need to think about it how to controll them efficient :)
edit:
maybe a shortcut between high and low pressure with a magnetic valve, but the compressor can start only *** times an hour because it needs to cool of a bit.wdrzal you have any toughts?
Tonic
09-06-2005, 10:32 PM
edit:
maybe a shortcut between high and low pressure with a magnetic valve, but the compressor can start only *** times an hour because it needs to cool of a bit.wdrzal you have any toughts?
Are you sure that's temperature issue?
Some of Low Starting Torque compressors needs to have equalized pressures
on both sides and then start to work
wdrzal
09-07-2005, 06:42 AM
compressors are contionious duty ,they should not need off time to cool if system is designed correctly. usually thermastats have a differental built in that allows suffecient off time for equilization.
ok this is all the stuff.
basically im connecting these 2 points to the thermostat.
to run compressor flat chat i normally just connect them together.
Open circuit and the compressor doesnt run.
http://www.xtremesystems.org/forums/attachment.php?attachmentid=36718&stc=1
wdrzal
09-07-2005, 11:59 AM
you can break it like that but you must be sure the thermostat is rated for the amp load of the compressor.
gclg2000
09-07-2005, 12:14 PM
you can break it like that but you must be sure the thermostat is rated for the amp load of the compressor.
OT: Walt your still the man. Great to have a experienced technicain posting like you do.
3 cheers for Walt
:toast: :toast: :toast:
wdrzal
09-07-2005, 12:49 PM
Kayl if that thermostat is not rated for enough amps you have 2 choices, either get one that is , or you can use the one you have in a control circuit with a magnetic contactor.
chilly1
09-07-2005, 04:21 PM
I need you to take some readings on teh relay rfor me please use the OHMs X1 scale..
http://www.xtremesystems.org/forums/attachment.php?attachmentid=36743&stc=1
chilly1
09-07-2005, 04:22 PM
I need you to take some readings on teh relay rfor me please use the OHMs X1 scale..
http://www.xtremesystems.org/forums/attachment.php?attachmentid=36743&stc=1
Please remove terminal connectors please....:)
wdrzal
09-07-2005, 04:48 PM
chilly why all the ohms readings?,I think he knows how to wire the relay as he had it running. He just wanted to wire in a thermostat. All he needs to do is break L1 as long as the RLA on the thermostat is enough for the compressor. I can see it but can't make out what it says.
chilly1
09-08-2005, 12:30 AM
Wanted to check the relay he had said ealier that the compressor wont start or maybe I misunderstood and the thermostat was not shutting the compressor down?? :)
Wanted to check the relay he had said ealier that the compressor wont start or maybe I misunderstood and the thermostat was not shutting the compressor down?? :)
the comrpessor works, theres a thread for it in the chiller section.
bascially in post 14 i remove that link and connect those 2 points to the thermostat here
thanxs for the drawing chilly,
thats how its wired. if ya still want ill measure the relay tomorrow.
wdrzal this is the details on the thermostat.
10/5 FLA
60/30 LRA
120 / 240VAC
i ran it agin tonight and this time place the hole wire inside the res.
liquid is at -14c now and not switch off still
http://www.xtremesystems.org/forums/attachment.php?attachmentid=36782&stc=1
wdrzal
09-08-2005, 09:04 AM
the 10/5 FLA (full load amps) is what you are concerned with. that thermostat will carry 5 amps at 240 volts and 10 amps at 120 volts. I dont know the voltage in your country? what is the voltage your compressor runs on? when running measure the amps its drawing.
wdrzal
09-08-2005, 11:12 AM
Kayle chilly was thinking ahead of me and wants the ohms readings because you may have to add a capacitor do to short cycling of the compressor.That thermostat probably has a built-in differential of 2 to 3 degrees and depending of the amount of coolant in the loop, short clycling may occur.So make the measurments for chilly, as there is a good chance you are going to have to add a capacitor.
the 10/5 FLA (full load amps) is what you are concerned with. that thermostat will carry 5 amps at 240 volts and 10 amps at 120 volts. I dont know the voltage in your country? what is the voltage your compressor runs on? when running measure the amps its drawing.
the compressor draws about .9A to 1A.
mains here is 240v.
ill get those measurements a little later.
I got some more stuff tonight.
2 more thermostats and a tinny little compressor :woot: