Capacitor - Midea MPM1-10CEN1-BB6 Technical & Service Manual

Apply "live" test cord probes on each of the remaining wires from the speed switch or
system switch to test intermediate speeds.
9.4

Capacitor

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 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 Capacitor test
Remove capacitor from unit.
Check for visual damage such as bulges, cracks, or leaks.
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.
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.
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.
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Basic test procedure