Carrier 30HXC Oil filter change

[freonguy]

Greetings:

I have a 30HXC126 on site that is ' new to me ' and has over 3,000 hours on it.

Oil pressure is sketchy at times, I am pretty sure the internal and external oil filters have never been changed ( paint is not disturbed and records are non -existant ) - The manual states the internal filters should be changed @ 200 -300 hrs.

I have new internal and external filters, a manual, and have a question or two:

It states when changing the external filter that ..... '' A quart of oil is typically what is removed during this process. ''

The next couple paragraphs go on to detail the internal filter changeout etc., but there is no mention of replacing the quart removed. I also have new oil, and would prefer not to re-use POE; is there any advice from you guys for this procedure and best way to replace the oil - of course I have a hand pump, can slurp it in under vacuum etc.

Any comments would be appreciated.

Dave Beauchesne CM
aka: Freonguy

[freonrick]

dont worry about the oil and make sure you have the oring for the internal. before you change it what is the pressure drop on the internal? the external should not need changing. the internal may not need changing either.

[txhvac]

Before you go changing the filter. What do you mean by sketchy oil pressure? Are you getting a high pressure drop alarm over 25 psid? Oil pressure minus condenser pressure. Low oil level? Low oil pressure? There are several different oil trips, what's your tower water temps? do you know if theres condenser regulating h20 valve. Check all your transducers, they all got schraders underneath them, put a brass tee on the port to check accuracy. Food for thought.

[chillerguy81]

Like Freonrick said, check the pressure drop. I think 10 psid sticks in my mind for the tolerence across the internal filter for a HXC. For the internal filter replacement you shouldn't loose much oil, maybe a cup or so. I would just run it fully loaded for an hour or so after you change the filter and add POE 220 as / if needed. A hand pump into the oil line service valve works fine.

[Dallas Duster]

There is a way of changing the filters without loosing at most an ounce of oil . But I must say that if the oil filters have never been changed then that is a really good sign.

[chillerguy81]

Txhvac is correct, check all you pressure transducers and such, forgot to add that part.

[Dallas Duster]

Like Freonrick said, check the pressure drop. I think 10 psid sticks in my mind for the tolerence across the internal filter for a HXC. For the internal filter replacement you shouldn't loose much oil, maybe a quart or so. I would just run it fully loaded for an hour or so after you change the filter and add POE 220 as / if needed. A hand pump into the oil line service valve works fine.

I'm gonna guess 20-25 psi filter drop.

[chillerguy81]

Do tell TGL

Oops you beat me typing, I ment for your filter changing method. I was just guessing for the pressure drop. I know it's in the IOM. I thought it was 10 psid internal and 20 or 25 psid external. I can check if anyone needs it for sure.

[tunaguy]

Look up the FD pressure in the pressure menu for both compressors. FD is the internal filter pressure drop. 10 psid is normal and 25 psid will go into alarm. The external oil filters rarely need replacement, however internal oil filters almost always need changing before 5000 hours. I'd change the internal if the FD was close to 20 psid.

[Dallas Duster]

Tuna I must say that that sounds like too much work and pretty risky of maybe loosing a compressor that way.

[freonguy]

Tuna et al:

Wow !! From all the replies in less than 12 hours, there must be a bunch of Chiller guys just waiting to answer a post !

Thanks for the info and insight - I am almost positive the internals havent been done; I will double check the readings - I have between 12 and 15 on the internal filters right now, so I will forge ahead and change them.

This unit doesn't have a suction valve to the compressor, onlt a DSV - I am stuck with pumping the low side into the high side I guess - I will do it on the run with evap. flow - don't want to pop a tube now, do we ??

Thanks again - will et you know how it went - -

Freonguy

[Dallas Duster]

You might want to read the manual about changing the filters. Then ad-lib from there , it's not as difficult as pumping out the cooler as some have implied!!!!

[Dallas Duster]

Do tell TGL

Oops you beat me typing, I ment for your filter changing method. I was just guessing for the pressure drop. I know it's in the IOM. I thought it was 10 psid internal and 20 or 25 psid external. I can check if anyone needs it for sure.

I will PM my method to you when I get an opportunity .

[freonrick]

you do not need to pump out the evap. valve out the oil line, there is a check valve next to the internal filter. hook gauges at where the internal filter is and bleed that off. when your done pull a vacuum at the same place.

[tunaguy]

Tuna I must say that that sounds like too much work and pretty risky of maybe loosing a compressor that way.

It really isn't much work, it's a lot faster than recovering all the refrigerant when you don't have compressor suction isolation. You can replace an oil filter in less than 2 hours. I talked to one factory guy that does this, so I know I can't be alone. I wouldn't have posted this unless he was a professional member. You won't lose a compressor unless you don't know what you're doing.

I've done this 20-30 times with no problems. However, maybe you're right. I probably shouldn't have posted this. Somebody may attempt this method without proper training. I will go back and edit my previous post. Thanks for your input.

[Dallas Duster]

I don't want to brag or anything, but it probably takes me 15 mins per compressor/circuit and lose minimal oil . I hate cleaning up an oily mess.

[bobby m]

What do you guys do when the internal checkdoesn't hold back all the pressure?

[freonrick]

I never had one fail. but if it does then I would get a new one and evacuate the compressor and replace. if no suction valve then the evap would need to be sucked out also.

[Dallas Duster]

Ow do you know itsleaking by?

[Carrene #2]

Ow do you know itsleaking by?

Do you want to know if he knows, or do you need to know?
Do gauges ring a bell?