MemberNovember 9, 2019 at 7:47 am
Scotsman MC46 evaporation temp too high. The machine cuts out after 15 min. We have checked all probes, all valves and even replaced compressor. Still getting same problem. Any advice??
MemberNovember 9, 2019 at 9:08 am
Evaporator temp is too high?
Did you check your expansion valve?
Give us some pressures, high side, low side, SC, SH and we can probably figure something out.
fixbear - ADK NYMemberNovember 9, 2019 at 12:08 pm
A MC is not a common ice machine. They were built in the 80’s. But I’ve never heard of a 46. You never stated if it was air or water cooled. Regardless, we need to look at the basics before going into the metering system. The part that relates to high head is normally the condenser side of the refrigeration system.
Being the air cooled MC’s used two fans one should check those first. If one is not running it will not move enough air through the condenser to cool. Make sure they are at full speed. Also is the condenser clean. Dirt, dust, and grease will reduce it’s capacity greatly. Measure the compressor discharge temp and the condenser discharge temp. If you have a near normal discharge temp but a high head temp you may have non-condenseable’s in the system. I’ve also seen this with a improper refrigerant in the system or a overcharge..
On the water cooled model one needs to check if the water pressure is enough to flow, If the water regulating valve is opening with head pressure, And if water is flowing through the condenser. Sometimes they do get a mineral build-up and flow restriction with bad water You can check flow with a screw driver by lifting the regulator flow spring and watching the out flow. Discharge water temp should be about 70 to 80 F when the machine is running. Water cooled machine will tolerate a over charge better than a air cooled..
Due to the err that it was in service we do know that it has to have been converted to a more modern refrigerant. I don’t remember if they were R12 or R502. Let us know the original and what is in it now as well as the compressor make and model. Not all replacements will work right with this machine.
fixbear - ADK NYMemberNovember 9, 2019 at 12:34 pm
If this is a newer machine, then we have the wrong model number It may be one of the Gormet cubers, but then the model will be one of these;
Not a MC 46. These date from 2012
fixbear - ADK NYMemberNovember 9, 2019 at 1:57 pm
After doing a bit of extensive digging, Your fan motor if air cooled is controlled by a triac via the thermistor in the condenser coil. If that sensor or the triac are bad it will do what your saying. Tempurature measurements are a must here.
MemberFebruary 26, 2020 at 12:02 am
Lots of possibilities, to many to really list. I would start with your pressures and what they do over the 15 minute time frame. I know generally some common Scotsman issues for that sort of error is low refrigerant, dirty coils (maybe a bad fan). But there’s not really enough info posted to be much help.
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