york yscabbs1cgas

[hvacrburgess]

We have a york water cooled chiller with a flooded evap. The problem has been that its experiencing high discharge pressures. So far we have cleaned the pumps,strainers, cooling tower and even punched the tubes. This had no help on the head pressure which is running 74/252. We decided that the unit might be overcharged and his would also explain the the loss of oil in the seperator. We removed about 40 lbs of r22. The end result was pressures of 52/233. the head pressure dropped some and now we are going out on low pressure or a bad evap sensor. Slider valve only opens up to about 76% and we are running 100% motor amps. Any suggestions on what could be happening? I think we need to check the flow orfice but the boss don't. Please help. Whats the correct way to obtain your superheat. If anyone has a tech manual on this screw unit i could really use it. Thanks

[Nuclrchiller]

To start with, what are entering condenser water temp, leaving condenser water temp, entering condenser water pressure, and leaving condenser water pressure ? Be sure to use a single gauge to measure water pressures, to rule out the possibility of gauge error. Move that one gauge from one port to the other to take the readings.

[KnewYork]

Slider valve only opens up to about 76% and we are running 100% motor amps.

Slide valve position and motor current do not go hand in hand necessarily. Like Nuclrchiller said we need some additional information.

[KnewYork]

Check your email inbox.

[servicetrane]

inhibit slide valve loanding 251.3 psig
allow slide valve loanding 250 psig

leaving condenser water =?
entering condenser water=?
sat. cond. temp?

[hvacrburgess]

hThanks,
The entering water temp for the cond. is 80 and the leaving is 87
Entering evap is 64 and leaving is 60 which low. will get pressures later when I get back to the job.

[KnewYork]

The design data may help as well. If you have a 10 degree machine then something isn't quite right because you are doing more work in the condenser than you are doing in the evaporator. If you are doing 7 degrees in the condenser then you should be doing 7 degrees in the evaporator. If you have a three pass evaporator (12-14 degree evaporator) then you should be doing a higher delta in the evaporator than the condenser.

[Nuclrchiller]

Take surface temp of condenser head on end opposite of piping. If warmer than leaving water temp of condenser, there is water passing thru/by the divider in the piping end head.

[servicetrane]

leaving condenser water - sat. condenser temp= aproach condenser

[klove]

Take surface temp of condenser head on end opposite of piping. If warmer than leaving water temp of condenser, there is water passing thru/by the divider in the piping end head.

?

[Nuclrchiller]

?

I'm not sure what you're questioning, klove. The method of the test? The need for the test? It appears to me the OP may have flow issues on both the evaporator and the condenser, with condenser issues being the original complaint. This test for a bypassing divider plate is extremely easy (an infrared thermometer is usually sufficient) and very quick. In my opinion a quick and easy way to verify, or rule out, the possibility. At least on a large amount of bypass. Not sure about a small amount, but I think it would provide some evidence. In fact, I make this a normal part of a run inspection.

[klove]

I'm not sure what you're questioning, klove. The method of the test? The need for the test? It appears to me the OP may have flow issues on both the evaporator and the condenser, with condenser issues being the original complaint. This test for a bypassing divider plate is extremely easy (an infrared thermometer is usually sufficient) and very quick. In my opinion a quick and easy way to verify, or rule out, the possibility. At least on a large amount of bypass. Not sure about a small amount, but I think it would provide some evidence. In fact, I make this a normal part of a run inspection.

Sorry, B. Misread your post and hit the button too quick. My apologies.

[Nuclrchiller]

Sorry, B. Misread your post and hit the button too quick. My apologies.

No problem. And no apology needed.

[OSCAR E & E]

I had that problem once and the problem was the liquid line dryer, y don't remember if this model has it, the other is to check your instrumentation values with other gauges and thermometers, ampmeters.

[servicetrane]

a dirty filter drier in these machines causes poor oil return

[OSCAR E & E]

i'm sorry, i thought it was a smaller chiller, these machines have an electric flow control and it's contrlled by the optiview considering several parameters, i think it's a control or sensor problem, i had a problem once with a broken cable in the low pressure transducer and it wasn't reading well, it was giving a low pressure value.

[KnewYork]

i'm sorry, i thought it was a smaller chiller, these machines have an electric flow control and it's contrlled by the optiview

The chiller in question doesn't have an Optiview control panel. It's a style "A" screw that came out before Optiview. This chiller probably was built in 1990-91.

a dirty filter drier in these machines causes poor oil return

I don't believe the OP has mentioned anything about oil return being a problem.

[Cadrion]

Actually, the OP does indicate they've lost oil out of the seperator. I wonder if a bunch of oil was added to the machine and is logged in the evap. I know when you loos oil into the evap you can get the transducer error. This could explain the lower than usual delta on the evap but not the out of equal numbers when compared to the cond. May even explain the high pressure if someone added a ton of oil. Personally, I'd probably do as others have suggested and verify the calibration of the related sensors-temp and pressure- garbage in is garbage out. Then let that baby sit for a while and equalize out on temps and check the charge of a load of noncondensibles.

[KnewYork]

The OP hasn't been on the forum since 8/9. Maybe he could tell us what he discovered.