T-K Sentry Two

[reefertech]

Im having a problem with a T-K Sentry Two. R404A. High discharge and suction pressure. 35 degree box temp. 375 discharge and 50 suction. I have already checked all the basics. Any ideas??

[Latte]

First of all, i am assuming when you say 35 degree's you are taking about fahrenheit and not celsius.

I say that because in our money (C) 35 would be around 3 degree's c. If so then 50 is if anything slightly low, would expect about 56-58ish.

Do you know the history of the unit, has it had any gas work done. I am afraid i don't know anything about these units, looks like they are a US spec although Reeferjon or MRW might tell me different. Assuming the condensers are clear and the fans all working the only thing i could suggest is to reclaim, change drier vac out and regas in case there is any moisture in the system and at least this way you know for sure you have the correct charge.

Can you give us more details of the unit and what you have done. The old sentrys over hear were all belt driven, i hope TK have come up with a better system by now

regards

Fatboy

[wambat]

Possible causes of High Suction Pressures
· Refrigerant overcharge.
· Bad compressor valves.
· High cooling load.
And possible causes of hi head pressure
· Refrigerant overcharge.
· System operating temperatures.
· Non-condensable in system.
· Outdoor coil fins dirty or covered.
· Outdoor fan motor bad.
· If someone recently worked on this system you may want check the superheat and subcooling.

[reefertech]

Thanks for your help. This unit is in terrible shape. Although the pressures are high it does eventually reach setpoint. It is a multitemp trailer so there isn`t much freezer space. So I went ahead and put back in service. I had just replaced discharge service valve, evacuated and recharged with 11.5 lbs. or R404A which is what the data tag specified. I dont know what the system pressures or how well it was cooling before I worked on. Maybe I made a mistake and overcharged?? I dont think so because I weighed it in. Thanks again for your help.

[andy towle]

hi all
is this the same as a sentry tc?i know this manual would come in handy! for r502 it says 13lbs of gas so i would expect the r404 weight to be similar. check the belts are taught,the condenser fan is central in the venturi and steam clean the condenser, high exhaust stacks kill coils and comps. sl-tci and spectrum pressures are around 280hp 45-55suction pressure at 0'c