Sabroe CMO 26 high suction temperature

[paddyraf]

Hi all, I'm relatively inexperienced with air conditioning, and am a second engineer in the merchant navy.
Just joined a ship and having problems with a Sabroe CMO 26 recip, high suction temperature, high crankcase temp, and high discharge temp. System is running on R404a, seems to be plenty of gas in the thing. HP 15.5bar, LP 6.0bar, suct temp 30 deg C, evap outlet air temp at 19 deg C.

Apparently, the suction and discharge valve plates were all changed for new a few days before I joined.
Suction temp on other compressor is 23 deg C with evap outlet air temp at 13 deg C. Grateful for any ideas guys....Paddy.

[chillyblue]

definatley sounds like a discharge valve not sealing, or unloading gear not lowering properly to me. check the discharge valves (you can sometimes measure excessive temps from the cylinder head thats failed) also check the unloading gear, there is a measurment you can take from the bore head to the top of the unloader rack.

CB

[GHAZ]

Hi Paddyraf it could the o rings around the liner are damaged or missing,or thin v/plate gaskets,or the dischage ring is not seated properly on the discharge plate

[josef]

leaking discharge plate

[josef]

suggests a lot of bad by-pass valve

[Grizzly]

All the guys have made good suggestions,
Checking the head temps as an indication is a good one!
Also to clarify Josef's point.
These symptoms could be caused by the safety valve between the discharge and suction passing?

I am assuming that if this comp is running on a unisab controller that its' operational settings are the same as the other.
You have not had someone finger poking, have you?
Grizzly

[narkom]

To check all the suggestion one can run the compressor with the suction valve closed. If the discharge plate is leaking the vacuum in the crankcase will never be achieved.

[paddyraf]

Okay now, let's see if I can stay online enough to post. Thanks for all the good suggestions guys, I'll let you know how I get on.

[Gary]

Very high superheat.

Looks like a high side restriction to me (plugged drier, kinked liquid line, plugged TXV strainer, etc.).

[RANGER1]

Probably didnt use jacking plug to lower unloading gear before putting head/s on !