Compressor sensors

Paul S_3

Hey everyone just want to know what these four sensors do on these compressors that I'm working on its a sixty ton or fifty air handler its packaged condensor is cooled by water from a cooling tower. These sensors are located on the compressor shell to the left of the electrical terminals they are hooked up to a solid state module right on the compressor this module has terminals.....m1, m2, t1, t2, s1, s2 etc..can any one help out??

Techman

Compressor,

What brand? Comp mn#

Techman

Statorstat

is what Carrier called their version.; 2 for power;2 for the module set of contacts;1 for the sensor's common, depending;and 2 or 3 for the sensors ,depending.The contacts have to be in the units wiring diagram. The sensors are imbedded in the windings,sensing heat. If one winding overheats{ lets say a loose lug in the disconnect],the sensor resistance changes,and shutdown!

Paul S_3

Thanks

Thank you....tomorrow I will get the make and model number. And you are right the module has 120v at terminals T1 and T 2 and terminals M1 & M2 is a set contact that is on series with the high low pressure switches to break power to the compressor contactor coil on the schematic it says to ohm out the sensors when they are at room temp......the resistance value is stated on the schematic I believe I saw! 750- 1000 ohms.....what will I read if they are at fault if I read too high or too low resistance??? And so you think rampage will change the resistance value???

Techman

Sensors

If every thing w/ the sensors/module is normal you will get the same resistance readings thru each sensor for a given temp. Temp changes and resistance changes. A loose electrical connection is a hot connection and that leg will overheat causing that legs amp to go up.Higher amps/heat and that  leg's sensor's resistance is out of whack from the other sensor's ,and shutdown!