CONDENSER FAN BLADE LOCATION
Dimension “A” will be from 2” to 4” depending on the unit model number. Be sure to check this
dimension BEFORE removing the fan blade.
Note: When parts combination results in motor /blade interference ,the fan blade should be
located to provide 1/8” motor /blade clearance.
RELAYS
ELECTRICAL OPERATION
Contactor coils are made with copper wires wrapped around a steel core. When energized, the coil
generates a magnetic field that moves the steel core to open or close the circuit contacts. Electrical
continuity
indicates a good coil. Relay coils use specific voltage. Using
a contactor with
the wrong voltage
coil will prevent the system from operating properly. This problem is avoided when using the proper
replacement part for a failed component.
can generate enough heat to weld the contacts together. Physical examination of the contacts
ELECTRICAL CHECKS
1.
BE SURE ALL THE ELECTRICAL POWER IS OFF TO THE COMPONENT BEING
CHECKED.
2. Remove at least one wire from the component being checked.
3. Measure the resistance of the holding coil with an ohmmeter
4. Measure the resistance across the normally closed (NC) relay contacts.
A. The resistance should be zero (0) ohms.
5. Measure the resistance across the normally open (NO) relay contacts.
A. The resistance should be Infinite (
∞
)
MECHANICAL CHECKS
AIR FLOW
characteristics.
Relay contacts are switches and can become pitted or corroded,
creating resistance. Resistance
will reveal this problem. With sealed relays, use an ohmmeter to test for open or closed contacts.
A. A specific resistance indicates a good holding coil.
B. Infinite (
∞
) resistance indicates a relay with an open holding coil. REPLACE the defective
an appropriate service part.
relay with an appropriate service part.
B.
If the resistance is more than 0.2 ohms the contacts are pitted. REPLACE this relay with
B. If the resistance isn’t Infinite (
∞
),.REPLACE this relay with an appropriate service part.
In relays ,mechanical faults are few. But check relay body for signs of physical damage .
Indoor coil air flow in any air conditioning system is critical. Too much air and the system will not be able
27
Fi
g.
10-4
Fig.
10-5
Central Air Conditi
oning
Model: Heat Pump,
HR13-D2
