capacitor motor such as the compressor and fan motor. 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.
Run capacitor
hook-up line
side of the
capacitor is
marked with a
red dot and is
wired to the
line side of the
circuit
9.4.1 Capa
citor
test
1. Remove capacitor from unit.
2. Check for visual damage such as bulges, cracks, or leaks.
3. For dual rated, apply an ohmmeter lead to common (C) terminal and the other probe to the
compressor (HERM) terminal. A satisfactory capacitor will cause a deflection on the pointer, and
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 fan motor capacitor.
NOTE: A shorted capacitor will indicate a low resistance and the pointer will move 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.
10 Characteristic of temperature sensor