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5
FAN MOTOR (Figure 4)
A 230 volt single phase permanent split capacitor motor is
used to drive the evaporator blower and condenser fan. A
running capacitor is wired across the start and run terminals
of the motor.
The motor is totally enclosed and is protected with a line volt-
age overload located internally of the motor. The motor shaft
is stainless steel to resist corrosion.
FAN MOTOR – TEST
Disconnect power to the unit.
1. Determine that the capacitor is serviceable.
2. Disconnect the black lead from the circuit board.
3. Apply "live" test cord leads to the common terminal of
the capacitor and the black lead. The motor should run
at high speed.
SOLID STATE RELAY (Figure 5)
Two 50 amp rated 208/230 volt solid state relays are used to
energize the compressor and fan motor. Terminals 3 and 4 are the
208/230 volt line side. Terminals 1 and 2 are load side contacts.
FIGURE 4
FAN MOTOR
SYSTEM CONTROL SWITCH (Figure 6)
This switch is double pole, single throw. Check for continuity
between terminals 2 and 3, and 5 and 6.
FIGURE 6
SWITCH, ON-OFF
CAPACITOR, RUN
A run capacitor is wired across the auxiliary and main winding
of a single phase permanent split capacitor motor such as the
compressor and fan motors. A single capacitor can be used for
each motor or a dual rated capacitor can be used for both.
The capacitor’s primary function is to reduce the line current
while greatly improving the torque characteristics of a motor.
The capacitor also reduces the line current to the motor by
improving the power factor of the load. The line side of the
capacitor is marked with a red dot and is wired to the line side
of the circuit (see Figure 7.)
RED DOT
RUN CAPACITOR
FAN
MOTOR
COMPRESSOR
FIGURE 7 RUN CAPACITOR HOOK–UP
CAPACITOR – TEST
1. Remove the capacitor from the unit.
2. Check for visual damage such as bulges, cracks, or
leaks.
3. For dual rated capacitors, apply an ohmmeter lead to
the common (C) terminal and the other probe to the
compressor (HERM) terminal. A satisfactory capacitor will
cause a defl ection on the pointer, then gradually move back
to infi nity.
4. Reverse the leads of the probe and momentarily touch the
capacitor terminals. The defl ection of the pointer should be
two times that of the fi rst check if the capacitor is good.
5. Repeat steps 3 and 4 to check the fan motor capacitor.
NOTE: A shorted capacitor will indicate a low
resistance and the pointer will move more to the “0”
end of the scale and remain there as long as the
probes are connected. An open capacitor will show
no movement of the pointer when placed across the
terminals of the capacitor.
LED indicates
contacts closed
when lit
Line side
Load side
FIGURE 5
SOLID STATE
RELAY