# 404a ice manitowoc machine



## wetbar (Jun 6, 2009)

hey I have any ice machine model q y 0284 a that is not producing Ice. it seems to be doing several things the fan cycle switch is going off and on about every 30 seconds, but it is maintaining about 15 degrees subcool. the super heat is 50 degrees. The suction side ranges anywhere from 30 to 50 depending on the cycle. the error code its giving on the blinking light is too long to harvest. I'm not sure what Vapor saturation I am shooting for but I would assume somewhere around 10 degrees would be sufficient. I did add refrigerant and the fan would stay on if I severely overcharged the unit. I remove the charge and charged to factory charge 18 oz. it is about 60 degrees here so it should not be to cold. I have run this is 30 degrees before, but it does seem the hotter the better. when I take the cover off I notice it does make a full sheet of ice but will not drop it evenly, it seems to get stuck on one side and then starts to refreeze another sheet of ice before it drops that one. Any clues?


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## hvac instructor (Jun 8, 2012)

What are your low and high side gauge readings during ice making mode and harvest. sounds like not getting enough Freon during the hot gas bypass harvest. did you weigh in exactly 18oz. did you allow for the Freon in the hoses.


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## beenthere (Oct 11, 2008)

50 degrees of SH is too much. Sounds like a restriction. How thick is the ice before it goes into harvest. 

Also make sure the hot gas solenoid coil is completely on. Sometimes someone takes the screw out and doesn't put it back in.


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## wetbar (Jun 6, 2009)

The low side goes from 50 to 20 or so. The high side is all over the place because the fan is cycling. From 130 to 250 or so. Yes I weighed in exactly 18 oz including whats is in the hose. Subsoil looks good, but that is because the fan cycle. What should super heat be? Could the evaporated be dirty in that spot? Looks like it is only holing up about 2 inchs or so. If I help it out with my finger it worked 5 cycles. The ice thickness looks good we did adjust it a little but still hung up.


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## wetbar (Jun 6, 2009)

What kicks it out of defrost? Can we make it stay in defrost 30 seconds longer? Wouldn't the curtain switch end defrost?


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## beenthere (Oct 11, 2008)

Suction looks too low at end of freeze cycle if 20PSIG is at the end of the cycle.

Should be around 40 at the end of the freeze cycle. 

Re-adjust the ice sensor to 1/8". Thicker then that, and it takes too long to harvest.


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## beenthere (Oct 11, 2008)

wetbar said:


> What kicks it out of defrost? Can we make it stay in defrost 30 seconds longer? Wouldn't the curtain switch end defrost?


The current switch should end defrost. I believe 3.5 minutes is the max time harvest is allowed, before the error counter starts.


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## wetbar (Jun 6, 2009)

I adjusted the sickness again for even sicker on ice hoping the wait would pull it out faster. It worked for 3 harvests. then the 4th one got hung up again and re froze two sheets. I added more freon to try to get the numbers up no matter how much freon I add the numbers will not come up.


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## beenthere (Oct 11, 2008)

Recover charge. install new LLFD, re-adjust sensor back to 1/8". Then check hot gas temp, it should be at least 160°F.


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## wetbar (Jun 6, 2009)

The hot gas was 147 when I checked it earlier - on the other side of the valve was 135 degrees. so maybe the valve is not opening all the way but still 135 degrees should be enough to drop the ice I would think.


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## beenthere (Oct 11, 2008)

Needs to be a min of 165 from the compressor. 135 at the plate is not enough.


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## wetbar (Jun 6, 2009)

would a LLFD cause low discharge? I would think only low refrigerant or bad compressor would cause low discharge temp/pressure. The discharge gets split when the hot gas valve is energized, right? from the compressor, one goes to the condensing coil then to the LLFD the other goes to the evap for hot gas. If the LLFD or coil was clogged I would think it would send more discharge to the evap side. Or am I totaly off again? lol


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## beenthere (Oct 11, 2008)

Restricted LLFD would explain the low suction. 

it would also cause the discharge to be lower as the suction gas wouldn't have a lot of heat in it.

A weak compressor can cause it also, but your compression ratio is above 3 to 1, which doesn't indicate a weak compressor.


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## wetbar (Jun 6, 2009)

Any chance it could be the TXV? I just want to make sure I have all the parts when I go to the ice machine (120 miles). Once I replace the LLFD if I still have the same problem, what would be the next thing to check? 
I was going to add a schrader valve in a few places so I could check pressures in the future, where would be good places to add one? This is a learning machine and has been for years, I just didn't have room for it so I let a friend barrow/store it. I was thinking on each side of LLFD and each side of hot gas solenoid. Just a though sounds stupid but if I learn what pressures should be where it will only help me on the next one. I would love to put one just past the TXV but I think that would be asking for trouble.


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## beenthere (Oct 11, 2008)

wetbar said:


> Any chance it could be the TXV?
> 
> There is a chance that the TXV's bulb has lost some on its charge.
> 
> ...


On the discharge/outlet side of TXV won't tell you much, as its pressure will be a lot lower the its inlet pressure.


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## wetbar (Jun 6, 2009)

One last thought - I have done nothing since last post. This thing has made about 2 bins of ice a day for the last 4 days or so. It has been mid 60's to mid 70's and worked like a champ. Any clues why it works above 60, but not below. - Remember the fan cycling I told you about in the first post, I never remember that happening when I had it at me house. That is the only thing I can think of that has to do with ambient temp. When it was at my house I also ran it year round!

Once again thanks.


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## beenthere (Oct 11, 2008)

Could be the fan cycler got adjusted/bumped and is not allowing the head pressure to get high enough.


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