Carrier 30HXC Oil Trips

[kwhit]

I got a call at the end of the day today that their Carrier 30HXC had tripped on T028 low oil flow. I got to site and discovered that their cooling tower water was at 50deg. I throttled back the water and started up the chiller and once the temp was back to normal I re established full flow. Chiller continued to run with good oil pressure (18#). Customer stated that he has seen the chiller start up with 50deg water before and manage to not trip. I am begining to wonder that maybe the issue is a combination of both cold water and maybe a fouling oil filter or 2. I looked breifly at the filter check out procedure and found that it was not very clear in the manual. Can anyone clarify the procedures to check both the external and internal oil filters?

[chillerguy81]

I'm thinking if he has seen the chiller start with 50* entering condenser water it must have been a fluke thing. (that they started that is!) That is way to cold. Check the IOM again, the procedure for checking the oil filters is in there, I dont have one saved on this computer or I would check it. Manual gives you different filter drop pressures to determine if either filter needs replaced, can't remember the exact numbers off the top of my head. Filter differential pressure can be checked at the navigator.

[kwhit]

I totally agree with you about the water temp chillerguy81

Here is the procedure from the manual

This pressure differential (discharge pressure minus oil pressure, both
from pressure transducer inputs) is typically 15 to 20 psi
(103 to 138 kPa) for a system with clean internal and external
filters. To determine the oil pressure drop due to the oil lines
and external filter only, connect a gage to the oil pressure bleed
port (Service valve on inlet of external filter?) Compare this value to the discharge pressure (Compressor discharge pressure?)read at the
Navigator. If this value exceeds 10 psi (69 kPa), replace the
external filter. The difference between the gauge pressure (same gauge that I put on in step 1?) and
compressor oil pressure read at the Navigator is the pressure
drop through the internal oil filter. Replace the internal oil filter
if the pressure drop is greater than 25 psi (173 kPa) for 30HXC
and 30 psi (207 kPa) for 30GXN,R and 30HXA chillers

Please clarify

[mal_c]

Does the machine not have a condenser water throttling valve for cold starts?

[Dallas Duster]

70 degree water is the minimum water temperature period. I prefer 80-85 myself.

[chillerguy81]

I totally agree with you about the water temp chillerguy81

Here is the procedure from the manual

This pressure differential (discharge pressure minus oil pressure, both
from pressure transducer inputs) is typically 15 to 20 psi
(103 to 138 kPa) for a system with clean internal and external
filters. To determine the oil pressure drop due to the oil lines
and external filter only, connect a gage to the oil pressure bleed
port (Service valve on inlet of external filter?) Compare this value to the discharge pressure (Compressor discharge pressure?)read at the
Navigator. If this value exceeds 10 psi (69 kPa), replace the
external filter. The difference between the gauge pressure (same gauge that I put on in step 1?) and
compressor oil pressure read at the Navigator is the pressure
drop through the internal oil filter. Replace the internal oil filter
if the pressure drop is greater than 25 psi (173 kPa) for 30HXC
and 30 psi (207 kPa) for 30GXN,R and 30HXA chillers

Please clarify

The oil pressure bleed port is located ontop of the compressor near the oil press x-ducer, and yes I believe they are refering to compressure discharge pressure.

[Phisher]

I have 2 30hx chillers that use the same condenser water. They both give nuisance low oil flow diagnostics thru the winter. Summer comes and problem goes away. The customer use to work for JC and thinks she knows how to control the tower bypass but can't seem to get it right. Check your tower bypass operation. If the valve opens too soon you will get a gulp of cold tower water. The water will warm up in the condenser and the valve opens again and more cold water.

[servicetrane]

controls the operation of the fan tower enfriamiento.50 ° f is very low water temperature to a condenser, the DP is equal between the condenser and evaporated

[Dallas Duster]

Depending on how old your chiller is and what control type a comfortlink chiller will give you a filter drop in the pressure menu. If it's and older PIC controls you just have to subtract the oil pressure reading from the discharge pressure. It's pretty accurate with reading it with the transducers. To me it sounds like an older chiller because I was expecting a totally different alarm first before you got the TO28 .

[chillerguy81]

The oil pressure bleed port is located ontop of the compressor near the oil press x-ducer, and yes I believe they are refering to compressure discharge pressure.

Oops I ment compressor, not compressure!! lol

[kwhit]

The reason the water is so cold is because the chiller has been off for over a week and the temp outside has been around freezing. Usually the condenser water temp is not a problem on this chiller. I am guesssing this is probably the culprit. What would be an ideal net oil pressure?