Hoshazaki 1600

[300 Win Mag]

Have a ice machine, R-22. Pressures start out at 60 / 275.
They drop to about 40 and 250 and tubes start to freeze. About 20 mins into cycle, head pressure climbs back up to about 300# and ultimatly the high evap temp switch trips out the alpine board. Hot gas not leaking, bad txv?
Seems like it should be freezing faster than what it does. The compressor is also getting very hot when high side goes up.Remote cooled, cond clean and fans running.

[KB Cool]

I don't know the answer. But, I wonder if you got something going on with the bypass cooling.

[Joe Harper]

A superheat and subcool reading would be nice here. I would check for proper head master operation.

[MechAcc]

You said condenser clean. Did you clean it? Or does it look clean? If the latter clean it. Looking clean doesn't mean it is. The outside may look clean but the coil traps dirt.

[300 Win Mag]

Unit is cooled thru a refrigeration rack, no headmaster, entire rack is clean. I shut down unit when it climbed to 300#, I will go back and do more diagnostics. Did not get superheat etc. Was looking for a quick answer that maybe somebody had the same situation.

[iceman1947]

You have a crook TX valve, high side goes up as TX closes and not reopens. If age is over 5 years or you have been into the system, just changing the filter will not prtect the TX from debris blockage. Flow of evaporated gas later in the cycle as it builds up will keep the compressor cool, You are only getting high head pressure as there is no flooding back to compressor on end of cycle due to the defective TX valve. Not a big problem to change the TX, make sure you change the filter as well. Have 3 or 4 to change giving similar problems. Long cycles, most should be 20 mins or less, uneven freezing of evaporator half or minimal and uneven ice. Similar to low gas, your pressures OK. R12 is old gas and old machines, newer ones are on R404A, R502 old gas R22 not suitable even though some produced with this gas.
R134A some smaller models only 40kgs per day or less.
you should see the pipes into the evaporator ice up initally and then defrost silightly as TX valve closes and does not reopen. Normally evap pipes should stay frosted up to time of hot gas defrost, if there is frosting and change to lesser degree, you have a problem.
On pulling out the TX valve check to see if this blocking is the case.
Did machine gradually get like this or did it come on all at once?
Hope this helps
Have over 85 ice machines in stable. No (Hoshazaki), Scotsman, Manitowoc, Cornelius, Brema, these models by experience. Regards iceman downunder. Happy New Year

[skwsproul]

your pressures point to a restriction or maybe a slight overcharge. Super heat, subcooling and water temp would be more helpful. If coils are clean (like new) weigh in the charge and start from there. Actual batch time will vary upon ambient temp, water temp to list a couple of factors.

[itsiceman]

Regards iceman downunder. Happy New Year

Happy New Year 2009 iceman

I've seen the TXV thing too but it cuts out on high head presure when I find them

if that's what the OP meant last year

[iceman1947]

Oops, See you are on R22, these machines are suspct, as this is a medium temp gas -5.C suction, as before, really not a low temp gas-18--25.C suction as required by ice machines. These machines will tend to run higher compressor temps, as in airconditioning will eventually burn the mineral oil at high temps and ultimately ruin your compressor. Can be replaced by dropin R409A, but you still may have a blockage in your system. Blocked condensor, will run hot from startup, variances is caused by a variable....TX Valve.
Good luck, 2009 will cure the problemo!!!

[jpsmith1cm]

Unit is cooled thru a refrigeration rack, no headmaster, entire rack is clean. I shut down unit when it climbed to 300#, I will go back and do more diagnostics. Did not get superheat etc. Was looking for a quick answer that maybe somebody had the same situation.

Then you don't have an icemaker problem, you have a rack problem. 300# on r-22 is a bit high.

Get the head pressure under control.

[itsiceman]

Good luck, 2009 will cure the problemo!!!

I was thinking he got the cure back in 07

Hope he chimes in

[JRREFRIGERATION]

Is that condensor matched to the machine? Any thing else been tested other than PRESSURES?? The other numbers on gauges is temperatures... Amp Draw? discharge temp and (pressure) Liquid temp and (pressure)? ETC? were just blind here without some info thats all

[itsiceman]

Is that condensor matched to the machine?

Quickconnects

I've seen that before