Ice Machine

[Northdude]

Hi guys, sorry to bombard you with questions here but i need a bit of advice,
Firstly i have had a few call outs to a MAIDAID MC150A ice machine (similar to a Brema), the first call i did i found the tray where the ice is formed to be really iced up as if there was a defrosting problem so the ice wasnt dropping and building up. I manually defrosted the ice and set it away and watched it through a few cycles, everything worked fine, the ice stat kicked in the defrost timeclock, water flow into the tray was fine and hot gas etc was all fine, all the ice dropped from each cube,pressures are all fine as well. 2 weeks down the line i got called back again and find the same problem a mass build up of ice covering all the cubes. Just wondering if anyone has had a similar problem, because everything does its job when i am there i am a bit stumped as to why it is doing it every 2-3 weeks. Maybe ice thickness stat playing up? The defrost timers on these are the standard ones you find on Bremas etc, is there a way to increase the defrost time? I have had a similar problem in the past with a Scotsman but i managed to increase the defrost time using the dip switches and its been running fine since.

Secondly i have condemned a copeland scroll compressor, 3 phase, Mod - ZB21KDE - TFD - 524. The compressor is only a few years old, was making a lot of noise and wasnt pumping, its been a long time since i looked at a 3 phase comp, phase to phase on the incoming breaker i was reading
390V,397V,384V, and phase to neutral 224V,235V,216V, do these readings seem quite low and mis - matched or are they normal? Just wondering if it could be a factor(216V seems low). The readings are the same on the compressor as well.

And lastly does anybody have any parameters/instructions for a Gram Controller on a Gram 2 door bench fridge Mod - K1407CSHADL (cannot find anything on the net)

Sorry to bombard you with all this, any help will be much appreciated, thanks in advance

[cadwaladr]

one the voltage question of voltage it seems slightly low,is your meter 100% agood way to check if its a local prob test the 3 phase supply at a different premises,or try your single phase at your own home.

[monkey spanners]

The 'TFD' in the model no. designates 380/420V 3PH so its within spec voltage wise, but ideally the voltages should be nearly the same on all phases.
We don't live in an ideal world though and i have seen many comps running ok with similar readings.
Did you measure the run current on each phase to the compressor? A lost phase can make a compressor sound lumpy though i have only seen this on a recip.

Jon

[charlie patt]

is the ice machine the one with water pump and fan as one please advise

[DrFreezeMD]

To help you with the Ice Machine, One would need to know the type of Ice Thickness Control. Most that I have seen that have a Defrost timer have a Reverse acting Low Pressure switch to control thickness. Some use a Temperature Sensor strapped to Suction Line. Is the Ice Thickness within Factory Spec? Is the Head Pressure enough at all times to release the Ice from the Plate? Is the Compressor Body sweating or frosting (low superheat) Is the ice being formed on whole plate or just one area? Is this Ice Machine Air Cooled or Water Cooled (that could mean a lot) What were the Pressures in PSIG? What is your Superheat Reading? What is your Subcooling? What is compressor Amp Draw? Go back to the Basics and Collect this data.

[Northdude]

Thanks for the replys, yes i have tested my meter and its calibrated, checked the phases on the system today and each phase was pulling around 2A although compressor wasnt pumping so a compressor change is in order, the compressor is only 3 years old which is why it had me thinking.
Will be calling back to ice machine in the next couple of days so i will more info and let you know, thanks for the help!!!!

[Northdude]

Just to answer a few questions on the ice machine off the top of my head, the ice thickness control is a temp sensor on suction,the ice is being formed on the whole plate (checked the ice slots after about 4 cycles and all the ice was dropping fine), the machine is air cooled. Will get more data when i call back.
Charlie when you say water pump and fan do you mean condensor fan or the standard fans which are on a lot of pumps ie k20s etc

[charlie patt]

lot of the maidaids we do have the condensor fan blade on the back of the water pump so its one complete unit i have had problems with water pump failure on a intermittent fault but never had this fault with a seperate fan and water pump like the k20

[doormaster2008]

regarding the scroll compressor.have you tried swopping two of the phases over as these compressors only pump when running the correct way.

[transcoolchris]

Scrolls are also noisey if running wrong way