Removal And Replacement: Evaporator - Scotsman NME1250R Service Manual

REMOVAL AND REPLACEMENT: Evaporator

To Replace the Evaporator:
(Assuming all the steps for removal of the thrust
bearing, breaker, auger, and water seal have been
performed.)
1. Recover the refrigerant from the ice maker.
2. Unsweat the refrigerant connections:
a) At the thermostatic expansion valve outlet.
////////////////////////////////CAUTION/////////////////////////////
Heat sink the TXV body when unsweating or
resweating the adjacent tubing.
//////////////////////////////////////////////////////////////////////////////
b) At the suction line at the joint about 3" from the
evaporator.
3. Remove the evaporator.
4. Unsweat the drier from the liquid line.
5. After installing a new water seal in the new
evaporator ( see "To Replace the Water Seal")
resweat the tubing connections.
6. Install an new drier in the liquid line.
7. Evacuate the system until dehydrated, then
weigh in the nameplate charge. Check for leaks.
8. Install auger, breaker, breaker bearing
assembly, and ice discharge chute in reverse
order of disassembly. See "To Reassemble
Evaporator and Auger"
CHARGING PROCEDURES
Extra care must be taken when recharging this
remote system. No liquid refrigerant maybe placed
in the system at the compressor. DO NOT use the
RECEIVER
To Reassemble the Evaporator and Auger
1. After the gearmotor has been inspected, fasten
the evaporator to the gear motor, be sure that the
number of shims indicated on the gear case cover
is in place between the gearcase cover and the
drip pan gasket. Torque the bolts to 110 inch
pounds.
2. Lower the auger into the evaporator barrel,
slightly turning it to match up with the drive end.
Do Not Drop Into the Evaporator.
3. Complete the reassembly by reversing the
disassembly for the breaker & thrust bearing
assembly.
Head Pressure Control Valve
1. Recover system of refrigerant.
2. Break off process tube on the top of the OLD
head pressure control valve.
3. Unsweat old valve from tubing.
4. Unsweat old dryer from tubing.
5. Install new valve in place. Check for correct
connections and be sure that the number on the
side of the valve is "220"
6. Wrap the new valve body in wet cloths to heat
sink the valve body.
7. Sweat in the new valve and the new dryer.
8. Evacuate the system, and weigh the nameplate
charge into the receiver..
valves at the front of the unit for weighing in the
charge. All liquid refrigerant must be weighed into
the receiver through the "front seated" king valve.
KING VALVE
SERVICE PORT
August 1993
Page 31
NME1250R
CHARGING
CYLINDER