Hermatic klixon question

[manxaircrest]

Hiya all ..... forgive the ignorance .... however looking at a foster freezer cabinet (out of my field really) earlier that has a CAJ2446Z compressor that is tripping the klixon that is in the top of the compressor after 10 15 mins running time have checked wht I consider normal stuff (levels vacced etc) but still it does it .......... is there a test to "prove" the klixon ok, or as I am contemplating, Compressor renewal time is upon us ?? runs fine with no noises (with klixon in the air above the comp) it does run hot but really seems no hotter than the chiller next to it ? you can put your hand on it but you wouldn't want to leave it there too long !

Cheers in advance

Brian

[Brian_UK]

I suppose that if you could find the specification for the Klixon and the trip temperature then you could test it.

Temperature: maybe by heating in boiling water ??

Amperage: you'd have to find a way of overloading it.

Cheapest option perhaps is to buy a new Klixon and see what happens.

I assume that the amperage is not excessive.

[manxaircrest]

Hiya ..... wasn't aware that an amps issue could cause tripping but am now ? in other words didn't check amps ! .... left unit running with klixon away from compressor as didn't seem any detrement in doing that ? unit refrigerates fine, or seems to ? prior to that has struggled to pull temp for approx a year ! according to friend that owns it ? he even said earlier that he thought that it was supposed to stop even though it wasn't at temperature or on defrost ?

Cheers again

Brian

[Billy Ray]

blocked condenser / blocked capillary / SOG

above three or combinations of maybe possibilities

[GHAZ]

Hi manaircrest its RLA 3.8A,MAX CURRENT 7.5A, LRA 29A,the klixon opens at120c and closes at 69c, its start cap is 88uf and run cap 15 uf and winding reading at 20c is 2.2 ohms main and 9.2 ohms aux

[thebigcheese]

check amps pulled and then check compressor over heating. i take it the fans ok and condensers clean?

[manxaircrest]

Hi all thanks for replies I vacced out the unit with no problems or issues to full tor, recharged on 404 (as was) with 600g as stated on the rateing plate unit pulls down fine. fan working ok and condenser although not pristine does not appear blocked and pipework away from condenser is not hot (mildly warm)pipework into condensate tray and to condenser is very hot and is steaming away the condensate so I'm fairly sure its ok I have noticed however that the rubber feet on the compressor have seen better days other than that everything looks as i think it should ?

[rnine]

Your original post stated that there was another chiller next to the one giving a problem. If it was the same model compressor you could have swapped the klixons over from one to another. the outcome of this would have helped you in your diagnosis.

[thebigcheese]

if u mean all squashed down probly means comps been cooking herself

[THE WOMBAT]

I would Megga test the comp to determin what the insulation resistance of the windings are.

If the winding are below 500 ohms, then the compressor will turn into a kettel.

Every time i hear a kixon i go get my insulation tester, then test the caps, then test the winding resistance.

hope that helps

wombat

[manxaircrest]

Hi Thanks to all ..... comp on unit next door is of differant type to answer that one had thought of that .... comp has side electric box not top and was worried re the difference and the robbing peter to pay paul issue ..... also the mounts are all squashed down which was why i mentioned that coz I was along that thought train in that am going to price and avail a new comp 2 moz and give my friend that option as opposed to a replacement unit that he was considering ?? thanks to all again, all the very best Brian

[Slatts]

A CSR compressor will run hot and and sometimes cycle on the klixon when the run capacitor is stuffed. I'd suggest you check it with a capacitance meter. It should be within 10% of the capacitance written on the cap.
According to GHAZ that should be 15uf in our case.
As these compressors rely to a certain extent on suction vapor to cool the windings, check your total suction superheat.
if it's too high you'll also be cooking your oil due to excessive discharge temperature.