A LOOK AT SERVICE SAFETY
Compressor Motor and Component Information
33
Table 3-7: Facts About Capacitors
Capacitor Type
Compressor
Motor Type
Characteristics
Start Capacitor
CSIR and CSR
•
Designed to operate for only a few seconds
during start
•
Taken out of start winding circuit by relay
•
Excessive start capacitor MFD increases
start winding current, increases start winding
temperature, and may reduce start torque
•
Capacitors in CSR motors should have
15,000 ohm, 2 watt bleed resistor across
terminals
•
Capacitor rated voltage must be equal to or
more than that specified
•
Capacitor MFD should not be more than that
specified
Run Capacitor
RSIR, CSR, and PSC
•
Permanently connected in series with start
winding
•
Excessive MFD increases running current
and motor temperature
•
Fused capacitors not recommended for CSR
and not required for PSC motors
•
Capacitor rated voltage must be equal to or
more than that specified
•
Capacitor MFD should not exceed limits
shown in Table 3-8 on page 32