L'Unite hermetique wiring

[Chilly willy]

Hi everyone!

Can someone please help!!
I have been called to a Williams fridge with an L'Unite hermetique compressor, capacitor start induction run.Someone has had a butcher at it and blown the current relay that pulls out the start winding. I have replaced the relay but it keeps cycling. I am not sure if the compressor is siezed as it has a history of being recharged at least twice a year and may have no oil. I also noticed that the common terminal is conected to a live via a clixon and control. The start terminal to neutral through capacitor and run terminal to neutral through coil of current relay.
Am i wrong in saying that the common should be coneected to neutral and remaining pins to live!
Not to sure my book shows a diagram but supply labeled L1 L2 not L N.

[Abe]

Hi everyone!

Can someone please help!!
I have been called to a Williams fridge with an L'Unite hermetique compressor, capacitor start induction run.Someone has had a butcher at it and blown the current relay that pulls out the start winding. I have replaced the relay but it keeps cycling. I am not sure if the compressor is siezed as it has a history of being recharged at least twice a year and may have no oil. I also noticed that the common terminal is conected to a live via a clixon and control. The start terminal to neutral through capacitor and run terminal to neutral through coil of current relay.
Am i wrong in saying that the common should be coneected to neutral and remaining pins to live!
Not to sure my book shows a diagram but supply labeled L1 L2 not L N.

When you say cycling, how long does the cycle last?
Is it a few seconds, or longer

[ernestlin]

Hi, chilly. Basing on your information, this compressor's wiring connection may be CSIR type. So, Common terminal needs to connect L line via a overload protector. Other teminals are connected correctly.

[paul_h]

when you say cycling, you mean compressor humming and not doing anything until the klixon goes open circuit, or do you mean it gets running and underway for a few seconds then cuts out?
What type of amps is it drawing?
Have you checked the capacitor?

[Chilly willy]

Checked capacitor and its out by a couple of micro farrads which seems ok! It is the actual current relay that keeps cycling for may be a second or so every thirty seconds, Compressor dont start run though, getting voltage there so must be siezed. My clamp meter snuffed it so can't see what it's pullin.

Thanks for responding to my post anyhow!

[Ireland]

Am i wrong in saying that the common should be coneected to neutral and remaining pins to live!

Not wrong but not necessarily right.

With Hermetique's it doesn't matter which way you connect the phase or the neutral so long as the wiring is right.

[Rotax100uk]

get a megger on the compressor and see if the comp windings are blown. possible because the unit is a leaky the compressor has been running along time with little or no fridge in, sound like comp has had it!

[Peter_1]

Not wrong but not necessarily right.

With Hermetique's it doesn't matter which way you connect the phase or the neutral so long as the wiring is right.

We're speaking abouth AC current, so it doens't matter at all, for any electrical device.

You're sure the right current relay was installed?
Not every current relay suits for the job.

Try this once (if compressor isn't already replaced ) connect the compressor via an AC wall socket on the Live (clixon) and the Run (right under) Then connect with an isolated wire or with a pinch tool the Run with the Start (so right under with Left under) for a second or two and look what's happening.

A current relay only switches when the current through the windings goes high enough to close the contacts.As soon running current drops, the relay opens.
The phenomena you describes can have two reasons: wrong or bad relay and/or a high loading compressor.
I bet you have installed a wrong current relay, one for a smaller compressor.

[maddfridge]

sounds like the start windings on the comprssoer are ok but when the run windinding is switch on it is Useless

Get an ohmeter check the windings two small values should add up to the largest value give or take a bit

megger the comprssor out to check and shake it !!

if it rattles it should be free if not could be part siezed.

Also look at the drier if it has one has that been changed ! why ?

! had one of these with a blocked drier and it ran up pumped and could not keep going cleared blockage ran ok without tripping the klixon out

williams fridges are prone for leaking on the evaporatoers check that to because your compressor could be running and running

As r134a gets llow on pressure it actually nearly reaches freezing conditions before it goes in to vacuum

your client thinks things are ok and boom another comprssor goes up the swanney.

[Chilly willy]

Hi everyone thanks for all your help!

Problem now sorted! Customer explained to me that prior to my visit the system had been getting topped up with gas by another engineer, on my first visit I noticed current relay blown so I replaced it with exact same relay which kept cycling in an out as I mentioned, Checked all windings which all added up so not open or shorted. Decided to change compressor and recovered about twice amount of gas as on data plate, Changed drier and compressor and hey presto, she's a runner. Thank you all for your suggestions it's nice to know theres help when you need it!! Live long and prosperous!!!!

[wineman]

jesus christ it doesnt get anymore basic glad your not workin on my equipment

[Peter_1]

So, changing the compressor wasn't needed at all, just recovering some gass