About six months ago I replaced an unloader piston seal on one of three units on a site...complete stripdown was required and Trane were involved with the project from the word go.
On the same machine I now have an oil diff tripping problem..I first changed the filter but the problem persists...I notice that after about a minute of running (the oil switch is timed on startup) that the separator sump gets very cold as do the oil pipes...I have contacted Trane and the only common cause of carrying liquid over on these machines would normally be either overcharged (The charge was weighed into this machine) or low evaporator water flow...(the flow is fine and matches the other two units on site which run well).
I am wondering if the unloader piston seal has had a catastrophic failure allowing the full bore pipe of oil to bypass the seal and go straight into the suction side(where it would bleed slowly to when unloading normally)...would this chill down the whole oil sump in a short time????....on the last try I gave it I turned the controller switch to load and left it there.....there was NO increase in machine amps at all over the total run time of say two minutes....has anyone else had a problem similar to this????