United Technologies Carrier TRANSICOLD 68RM35-604-20, Operation And Service

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4-10
T-288
CAUTION
If unit was recently operating, be careful of
remaining hot coolant in the hoses when
disassembling.
h. Remove coil retaining bolts on each side of the
coil assembly (three each side). Pull top of coil
assembly forward and down to remove from
unit.
i. Reverse procedure for installing new heater
coil assembly.
4.14 SERVICING THE REHEAT COOLANT VALVE
(O.E.M. SUPPLIED)
The coolant valve requires no maintenance unless
a malfunction to the internal parts or coil occurs.
This may be caused by foreign material such as:
dirt, scale, or sludge in the coolant system, or
improper voltage to the coil.
There are only three possible valve malfunctions:
coil burnout, failure to open, or failure to close.
Coil burnout may be caused by the following:
a. Improper voltage.
b. Continuous over-voltage, more than 10% or
Under-voltage of more than 15%.
c. Incomplete magnetic circuit due to the
omission of the coil housing or plunger.
d. Mechanical interference with movement of
plunger which may be caused by a deformed
enclosing tube.
Failure to open may be caused by the following:
a. Coil burned out or an open circuit to coil
connections.
b. Improper voltage.
c. Torn diaphragm.
d. Defective plunger or deformed valve body
assembly.
Failure to close may be caused by the following:
a. Defective plunger or deformed valve body
assembly.
b. Foreign material in the valve.
It is not necessary to drain the coolant from the
system to replace a burned out coil. Replace a
burned coil as follows:
a. Place the rear control switch in the “OFF”
position.
b. Disconnect wire leads to coil.
c. Remove coil retaining screw and nameplate.
d. Lift burned out coil from enclosing coil assembly
and replace.
e. Connect wire leads and test operation.
4.15 REMOVING THE CONDENSER FAN MOTOR
When removing or installing the condenser fan
motor, the fan blade must be removed to prevent
any damage to the condenser coil.
a. Remove fan blade guard.
b. Using 5/16 ratchet or equivalent, loosen the
two retaining screws in the fan blade hub. The
fan blade will sit on the shaft of the motor.
c. Remove the four motor mounting bolts from
the bracket.
d. Remove the motor by sliding the motor down
and out from the fan blade and unit. Remove
blade.
e. Using a adhesive, secure the shaft key to the
serviced motor shaft or fan hub slot.
f. When installing the motor, secure the fan blade
above the shroud before mounting the motor.
Align the motor shaft through the fan blade hub
and secure motor mounting bolts.
g. Position the fan blade 1/3 (the height of blade)
below the shroud, tighten the two retaining
screws in the fan hub.