Qualitair Cellar cooling

Hi

Re
I have attended a few of these now and they all seem to have a trend with the compressors.
The compressor have a capacitor permanently connected to the start winding (no relay etc)

The problem i have noticed is that they seem to run fine but as soon as they have a fault or the temperature goes high or they have a high load they do not like starting!! and will just lock up and keep tripping on the clixion, they are then very difficult to get running again.

Anybody else noticed this and if so have you resolved it.

Cheers
CB

Can you be more specific, what compressor? wiring diagram? a photo?
It will help those whom will jump in to help you.

does it have a delay timer

Permanent start capacitors, been around for quite a while as it saves on components and the associated wiring. They can be modified to have a start relay, start and run capaictors if starting under load is a problem. Make sure that the condenser coil is not dirty, this will help to reduce the head pressure. You could modify the system to have a start delay timer to give the pressures a chance to equalise. Make sure that the refigerant charge is correct as there might not be enough suction cooling going on under certain conditions.

Are they still using l'unite rotary comps? - nasty. I haven't had the misfortune to work on one of these systems for a few years, but what I do remember about them was that the indoor unit had an expansion valve, the condenser didn't have a receiver. Every time you switched it off for maintenance, it would never restart. Ended up putting a bigger capacitor on it, probably not the correct thing to do, but it carried on for a few more years.
If it does have this expansion valve arrangement, you could take it out and put an Imi style restrictor in instead. At least it would equalise properly.
Alternatively, rip it out and put an Imi in with a recip compressor - job done, no more issues.

they have a mechanical stat then they have a high differential to compensate for the 3 min delay -to allow for equalisation of pressures- hence electronic controllers incorporate this-if you fit a delay timer then youll have to energise a contactor/relay coil as the timer wont last long with the start up load.
if it works-then legg it!!!

old qualitair/myson units had the c27 stat that if it cut out and you moved the dial to kick it back in then pop- fuse blown

the new units have a equalising pipe with a sloenoid valve fitted just above the compressor