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.
FIGURE 4
FAN MOTOR
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 5 |
| Line side |
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SOLID STATE |
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|
RELAY |
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Load side
LED indicates contacts closed when lit
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,
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.)
FIGURE 7 RUN CAPACITOR
COMPRESSOR
FAN
MOTOR
RED DOT
RUN CAPACITOR
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 deflection on the pointer, then gradually move back to infinity.
4.Reverse the leads of the probe and momentarily touch the capacitor terminals. The deflection of the pointer should be two times that of the first 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.
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