Manitowoc tech advice

[motojo]

Well I am working on an air cooled mani. It is really slow harvesting. Sometimes it trips the HPC during harvest. I know that there is a 3.5 min limit set by the board, but I have never had one trip the HPC. Is this strictly a harvest issue or is there something lying under the cover? This is a new machine to our company and it was/is in rough shape. We started by cleaning the machine and grid, no good, sometimes it drops others it wont. I have adjusted the bridge sensor to the point that it is making a heavy sheet. The grid is in fine shape, and so are all of the slats. The top of the grid seperates fast. the lower portion of the grid hangs up. Specificly in the lower left corner. Exactly where the hot gas enters the evap during defrost. Not sure what is happening here and thought I would try you guys. Soooo lets here what u think. Is the HPS tripping normal? And I am open to any suggestions.

[antiquepicker62]

I had that happen and it drove me crazy. Look for small wear or rust spots on the evaporator it will cause the sheet to hang up and the only way out is to replace the evap. Hope this helps

Frank

[marsmech]

What are the temperatures at the Outlet of the hot gas line going into the evaporator? I would suspect that you are having a txv issue and the temperatures will tell you along with what your suction pressure is during harvest. More information needed.

[Youngbeechnut78]

Sounds like a dirty machine. Clean and sanitize it after you clean the condenser coil. That is why your head pressure is tripping. I serviced a machine not too long ago that was having similar problems and coil was disgustingly filthy! Mine In particular was at a bar. Good luck and remember gauges are the last resort. In fact forget I mentioned the word gauges. Lol! These machines are critically charged.

[hvacpope]

Tripping on high pressure during harvest is kind of weird if any the head pressure should decrease, without the psi/temp is hard to guess whats going on, maybe the harvest solenoid is sort of plugged up or the coil is on its way out but that alone wouldnt make it trip on high head.

[itsiceman]

Could it be the TXV may not be choking off feeding the harvest loop?
Would the liquid line entering the TXV get chilly during harvest if that was the case?