Manitowoc UG Series, Руководство техника

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Part Number: 040006847 12/19 55
Diagnosing Start Components
If the compressor attempts to start, or hums and trips the
overload protector, check the start components before
replacing the compressor.
CAPACITOR
Visual evidence of capacitor failure can include a bulged
terminal end or a ruptured membrane. Do not assume a
capacitor is good if no visual evidence is present. A good
test is to install a known good substitute capacitor. Use a
capacitor tester when checking a suspect capacitor.
CURRENT RELAY
The relay has a set of contacts that energize and
de- energize the compressor start winding. The contacts on
the relay are normally open (start winding de-energized).
When power is applied the run winding will be at LRA
(Locked rotor Amperage). The relay coil becomes an
electromagnet and closes the contacts (start winding
energized). As the compressor motor RPM increases,
the run winding current draw and relay coil magnetism
decrease allowing the contacts to open. Replace a suspect
relay with a known good relay, or use a momentary switch
and start capacitor to mimic relay operation.