Carrier 30GX loosing oil

[mikeacman]

Tommyknocker.....

I'm telling troy what you did.

[R123]

So R123 what danger exactly are you referring too? Let's try this. In your expert opinion will the oil pump produce enough vapor refrigerant pressure to fool the oil pressure transducer if no oil is in the seperator?

No, the oil pump will not produce any vapor refrigerant pressure to fool the oil pressure transducer if no oil is in the seperator, and in that case the compressor won't start. But, once the compressor starts, the pre lube pump shuts down and at this point oil is flowing due to differential refrigerant pressure pushing the oil in the seperator, through the filters and oil solonoid valve, and on into the compressor. If the oil level runs out at this point (after the pre lube pump shuts down), then yes, the vapor refrigerant pressure could fool the oil pressure transducer. Thats why the oil level switch is in there.

[R123]

for differential oil pressure the controls look at the difference between the econmizer transducer and the oil pressure transducer .....the economizer transducer is the highest low pressure in the compressor and is higher than the suction pressure ...discharge pressure drives the oil but does not factor in the oil diff calculation .... Filter diff calc yes...oil press diff ...noooooo...

side note.. Their is about a billion software revisions .... I believe discharge pressure is watched to make sure it rises Fast enough and high enough to push the oil ...later on they started allowing the oil pumps to cycle back on if need be to eliminate nuciance shutdowns ...


the manual used to and may still have listed the Einstein equation the controls use to prove proper oil pressure . it can be very confusing.


If I'm wrong I'll quit the trade and go be a strip club DJ

If i make no sense I'll sit out in the sun again tomorrow and cook my brain some more then come back for seconds....

I think your right.

[Freightshaker]

If I'm wrong I'll quit the trade and go be a strip club DJ

After the evapco I fought today that sounds like a better career choice hahaha

[nique]

I have been reading this for days and have been trying real hard to stay away but alas I cant. Carrier procedure is to add oil (1/2 gallon)to get machine to start, operate in a high load state, check ref. charge and then remove the oil.
Now have I ever done this? let me just say that every one of my hx and gx machines have the oil level sensor wires striped at some point just wide enough for a jumper. I have never had to leave it on for more then 3 or 4 min. if you do its probably the charge or some other problem.
in this case the tubes are probably pluged and the unit is oversized which causes it to stay in a low load condition for extended times. clean the tubes, increase the deadband, start the smaller comp first, and properly check the charge. the oil is there, run the machine properly and it will be fine.

[Tommy knocker]

OK so we agree that the comp is protected from no oil on start if level switch is jumped out. Now once running would vapor refrigerant absent of oil produce the pressure differential the control is looking for?

[Dallas Duster]

So R123 what danger exactly are you referring too? Let's try this. In your expert opinion will the oil pump produce enough vapor refrigerant pressure to fool the oil pressure transducer if no oil is in the seperator?

I know this question is for R123 but under the right circumstances it is possible to have the control to start a compressor with the oil level switch open and the prelube just enough to make pressure.

[Tommy knocker]

I suppose. Sorta like a piece of straw can penetrate concrete "under the right circumstances"

[Dallas Duster]

I suppose. Sorta like a piece of straw can penetrate concrete "under the right circumstances"

Sure why not , open an oil level switch next time and start a compressor and see if it starts.

[Freightshaker]

Sure why not , open an oil level switch next time and start a compressor and see if it starts.

"I have been reading this for days and have been trying real hard to stay away but alas I cant. Carrier procedure is to add oil (1/2 gallon)to get machine to start, operate in a high load state, check ref. charge and then remove the oil.
Now have I ever done this? let me just say that every one of my hx and gx machines have the oil level sensor wires striped at some point just wide enough for a jumper. I have never had to leave it on for more then 3 or 4 min. if you do its probably the charge or some other problem.
in this case the tubes are probably pluged and the unit is oversized which causes it to stay in a low load condition for extended times. clean the tubes, increase the deadband, start the smaller comp first, and properly check the charge. the oil is there, run the machine properly and it will be fine."

^works for him, me, and others with no catastrophe. Nobody must do it this way it is just an option. These machines are notorious for this and it is just another option. Many people do this if they are familiar with the particular machine and it's history. Say for instance a compressor was locked out for some time while another compressor was running the oil may migrate and once brought back online it would have a fit. This is just a quick tip of getting it back up and gunning.

[Dallas Duster]

"I have been reading this for days and have been trying real hard to stay away but alas I cant. Carrier procedure is to add oil (1/2 gallon)to get machine to start, operate in a high load state, check ref. charge and then remove the oil.
Now have I ever done this? let me just say that every one of my hx and gx machines have the oil level sensor wires striped at some point just wide enough for a jumper. I have never had to leave it on for more then 3 or 4 min. if you do its probably the charge or some other problem.
in this case the tubes are probably pluged and the unit is oversized which causes it to stay in a low load condition for extended times. clean the tubes, increase the deadband, start the smaller comp first, and properly check the charge. the oil is there, run the machine properly and it will be fine."

^works for him, me, and others with no catastrophe. Nobody must do it this way it is just an option. These machines are notorious for this and it is just another option. Many people do this if they are familiar with the particular machine and it's history. Say for instance a compressor was locked out for some time while another compressor was running the oil may migrate and once brought back online it would have a fit. This is just a quick tip of getting it back up and gunning.

So it's safe to say that you are doing performing a repair incorrectly against factory recommendation and risk and accept the consequences?

[Freightshaker]

So it's safe to say that you are doing performing a repair incorrectly against factory recommendation and risk and accept the consequences?

Guilty as charged I guess. I read an Evapco manual yesterday and it mentioned waxing the stainless steel components in their cooling towers. I can't really say I do that either or ever really heard of anyone doing it.

[Dallas Duster]

Guilty as charged I guess. I read an Evapco manual yesterday and it mentioned waxing the stainless steel components in their cooling towers. I can't really say I do that either or ever really heard of anyone doing it.

Just don't jump out the vibration switch thinking its going to wax its self.

[mikeacman]

Just don't jump out the vibration switch thinking its going to wax its self.

ha haha ha haaa ha..

That's a good one!!!

[CCSPIERCE]

In 1997 Carrier's engineers released a warning about jumpering the oil level switch. They stated that they had proven a lack of oil level in the seperator would allow a mixture of oil and vapor to prove differential oil pressure requirements for start up and run. In 2002 i was told by a Carlyle engineer that they had deliberately run 06N compressors without lubrication, but WITH adequate refrigerant flow thru the screws, they would last about an hour. The combination of foamed oil or no oil with low flow of refrigerant thru the screws is the killer. If you jump it out you better have good refrigerant flow thru the compressor. The compressor may not fail that day but in a few months you will be listening to a screamer with high amps.

I speak on this with personal experience, don't do it, when in doubt put oil in the reservoir and make the machine recover oil.

[Freightshaker]

Just don't jump out the vibration switch thinking its going to wax its self.

I threw away the jumpers for they have sinned. I ordered a power buffer for the truck incase a customer decides to actually care for their tower before it's 5 years too late. Also tossed a lawnchair on the truck so I can sit back and enjoy the oil return safely

[Dallas Duster]

I threw away the jumpers for they have sinned. I ordered a power buffer for the truck incase a customer decides to actually care for their tower before it's 5 years too late. Also tossed a lawnchair on the truck so I can sit back and enjoy the oil return safely

Well at least the mechanical room floor will look shiny when the compressor fails. Then you will have some thing to fall back on.

[Tommy knocker]

Do it don't do it it's every tech's call. I have done it. I have read it in a 30GX manual. Perhaps that manual was printed in 1996. Who knows. But it is an option. Never said jump it and leave it. It only took a few minuts when I have used this technique to get enough oil back to make the switch. Just because someone thinks they are the smartest tech in the room or they are the sole expert with the only answers that are correct does not make it so. I have several of these machines under my care and have been taking care of them for several years. I have replaced barrels and other various parts. What I have not yet had to replace is a compressor. Most of them are 1990s. Don't do it. I don't care. But don't insult people who do things different then you. Your way is not the only way. Niether is mine. But both obviously work.

[Cadrion]

Wow...this thread sure went ape ****. It does all come down to personal procedure when dealing with servicemen. Personally, I don't jump safties unless I know they are shot AND there is a dire need for the equipment to run AND the client understands the potential consequences. A gallon of oil and piece of mind is far less expensive and easier to explain the a dead compressor- that's my motto. Following factory procedure is a great idea and a great way to cya. The 30GXR249 I initially posted about is still purring away.

I bet the tech with the appion under the machine was trying to pump oil laden refrigerant from the cooler to the serperator with the hopes of driving the refrigerant off with the heater...thought of that one while I was there but it's a little iffy if you are at a saturated temp in the seperator- can't know if the refrigerant has boiled off.

As I thought about the AOP on these machines I came to the conclusion it's a great idea- the York and Trane chillers I've worked on rely on discharge pressure to build fast to get oil flowing- I find it hard to believe they are fully protected every start for the first say 10 secs...of course the GXR is quite a bit smaller compressor. I like seeing all the ideas that all the oems come up with....sure a lot to learn.

[Dallas Duster]

Do it don't do it it's every tech's call. I have done it. I have read it in a 30GX manual. Perhaps that manual was printed in 1996. Who knows. But it is an option. Never said jump it and leave it. It only took a few minuts when I have used this technique to get enough oil back to make the switch. Just because someone thinks they are the smartest tech in the room or they are the sole expert with the only answers that are correct does not make it so. I have several of these machines under my care and have been taking care of them for several years. I have replaced barrels and other various parts. What I have not yet had to replace is a compressor. Most of them are 1990s. Don't do it. I don't care. But don't insult people who do things different then you. Your way is not the only way. Niether is mine. But both obviously work.

The 4th sentence needs to read that this is your opinion and is not a real option.

Just my two cent.