Trane ERTHA300

[Superheatman]

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????

[PETER MAHONEY]

Hi
Check the oil pressure drop across the filter & check that the oil pressure switch is closing on start up

[centrecipew]

John, Is that You??

[GHAZ]

hello superheatman what compressor model do you have on this chiller

[Superheatman]

hello superheatman what compressor model do you have on this chiller

Hi...sorry..left details in vehicle...will reply when back at work.

[Lowrider]

What are chilled and cooling water temperatures during start up?

[serviceman]

DEAR FRIEND
CHECK THE CONNECTIONS OF THE DIFFERENTIAL PRESSURE SWITCH OIL, OTHER CAUSE THAT IS THAT MAY BE WATER COOLING TOWER is very cold, typically when the valve seal is damaged COMPRESSOR NO CHARGE IF YOU NEED TO HAVE THE MANUAL OF FAILURE OF RTHA300

[FreezerGeezer]

Hi
Check the oil pressure drop across the filter & check that the oil pressure switch is closing on start up

Pete, I have this feeling in the back of my head that Basingstoke had this problem with an early RTHA. Might be worth checking with AA or TW? It's too long since I last worked there to remember for sure.

[goshen]

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????

hi does your head pressure control work?
off hand it seems like u have a leek in oil pressure that would cause this trip .
if this problem did not occur before u are right to zero in on the seal ofc the unloader system .
if u are not able to load the comp manualy u deffinatly have a proble with oil pressure reaching the slide valve or the seal on the valve is broken ,u also might have an obstruction in the oil pass not letting oil into the loader u should check this attached article should shed some light on your problem
http://trane.com/Commercial/Uploads/...N_09012005.pdf
mail me at gill@gosheneng.co.il i will mail u the slide valve manual from trane!

[serviceman]

VALVE TAKE CHARGE AND DISCHARGE OF A FILTER BRONZE sometimes obstruct, CHECK TO OPEN THE CONTACTS OF THE DIFFERENTIAL PRESSURE SWITCH OIL, OIL PRESSURE MEASURED OUTPUT FILTER WING AND UPPER WINGS NEAR COMPRESSOR LOAD SOLENOID , CHECK THAT IS NOT SOME CAPILLARY DUCT

[wilko123]

Can anyone advise the procedure for changing the oil filter on a RTHA?

Thanks in advance

[CV_Geardrive]

Hi wilko,
Please check attachment.
Please always create a new post!
Regards,
CV