Trane RTAA 215// circuit a,b intermittent low oil flow codes 199

[BKS60]

Ah what will we all do when all the AA's have passed into the twilight now that Trane has moved on to AC's! It's fun to watch or at least read these responses!

And I have learned alot reading them between the laughs!!

[aggiechillertech]

Washed the condenser last night it definitely was way dirtier than it ever looked. The switches tested out when I checked their calibration. The machine ran perfect through the night and all day today. Maybe I got lucky we'll see how it does over the next few days.

The x number on the switch is x1324004040.

[Nuclrchiller]

Ah what will we all do when all the AA's have passed into the twilight now that Trane has moved on to AC's! It's fun to watch or at least read these responses!

And I have learned alot reading them between the laughs!!

Not to worry, BKS. The "entertainment value" of the CGAM on this site looks promising!

[BKS60]

Good point!
How many techview questions will it take to before our northern Trane guru has to take his green machine out in December with the top down to cool off.

[Healey Nut]

Good point!
How many techview questions will it take to before our northern Trane guru has to take his green machine out in December with the top down to cool off.

The Green Machine will be tucked up and sleeping come December ...........so I'll just have to drop my shorts and plonk my ass in a snowbank instead ...........probably have the same numbing effect !!!!!!!!!

[BKS60]

The Green Machine will be tucked up and sleeping come December ...........so I'll just have to drop my shorts and plonk my ass in a snowbank instead ...........probably have the same numbing effect !!!!!!!!!

Keeper safe she's a good lookin ride!

[aggiechillertech]

So far so good today had a few VAV boxes to work on and she ran like a top all day.

[aggiechillertech]

It got pretty cold here last night mid to low 30's and at some point in the night both circuits tripped out on low oil flow. I check over everything one more time today and it is running like a top and all of the specs look normal. Does anyone have any idea what this thing could be doing when it gets cold outside to cause this.

Thanks

[aggiechillertech]

I just thought of one possibility. The building this is in is largely unoccupied and is holding the chilled water at 42 degrees with ease and there is very little load on this unit in cool weather and today it's 65 degrees outside and it will run 5-15 minutes and be off for another 10-15 and is able to get by running one compressor at 40% load on the average and hold the building absolutely perfect. this chiller supplies cooling for multiple buildings and unless there is an activity slated very seldom are all zones calling. Today it pretty much is cooling some offices and a large entry area.

During the summer it can hold the building perfectly with one circuit running and all zones calling in 112 degree weather and still hold about 50-55 degree water.

Could the short run times and long off cycle during the night be causing this and if so where to look.
Thanks

[jayguy]

the number 1 cause of oil pressure trips is dirty condensers. the higher head pressure pushes the oil through the oil filter, piping and solenoids faster than normal and this causes the higher pressure drop which trips the unit.

you may still have a similar issue. perhaps the outdoor air temperature sensor is faulty or sometimes flaking out (it is used for pre-staging the fans). if it sees lower outdoor air temperatures than actual, then it may not be bringing on enough fans fast enough.

also check your saturated condenser and evaporator temperature sensors for accuracy. these are used to control the fans after start up. also, check to make sure that the fan contactors are wired properly. perhaps fewer contactors are coming on when the unit thinks/expects they are.

[aggiechillertech]

I used a pressure washer to clean the condenser I washed it from both sides inside and out and got a ton of dirt out of it. I especially washed the oil cooler areas real close.

If it is a fan staging issue or a temp sensor going wacky will it make her start tripping on a low oil flow code before the head pressure is high enough to knock it out on high head. It just blows my mind that the friggin volume could get high enough through the filtration system before it ever trips out on high head.

[klove]

If it is a fan staging issue or a temp sensor going wacky will it make her start tripping on a low oil flow code before the head pressure is high enough to knock it out on high head.

Yes

[jayguy]

...It just blows my mind that the friggin volume could get high enough through the filtration system before it ever trips out on high head.

i do not know if that is a by-product of design or if trane intended it to be that way on purpose as a back up safety. it is probably a by-product of design, however, oil flow issues usually trip the chiller before high pressure safeties trip.