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TM 5-4120-361-14
c.
Test.
Using a multimeter, test
for continuity across each pair of ter-
minal connections.
If continuity is not
indicated, the thermal protector is de-
fective and must be replaced.
(b) Using a multimeter, test for
continuity by placing one test probe
against the motor housing (on bare metal
only) and the other probe against each
of the motor winding leads.
If contin-
uity is indicated, the winding is
grounded and the motor should be re-
placed.
d.
Installation.
(1) Refer to figure 4-8, install
thermal protectors.
c.
Removal.
(1) Refer to figure 4-4 and remove
the condenser cover and top rear cover.
(2) Refer to paragraph 4-21e and
install evaporator fan and motor assem-
bly.
(2) Refer to figure 4-9 and remove
the condenser fan and motor assembly.
4-23.
Condenser Fan and Motor Assem-
bly.
d.
Installation.
a.
General.
The condenser fan mo-
tors are multispeed motors.
The 400 HZ
motors operate at 3750 RPM in high speed
and 1800 RPM in low speed.
The 60 Hz
motors operate at 3450 RPM in high speed
and 1725 RPM in low speed.
The motors
contain separate windings for high or
low speed operation and each winding is
thermally protected.
Motor speed is au-
tomatically controlled by an outdoor
thermal switch (figure 1-2).
The motors
will operate at low speed until the out-
door ambient temperature rises above
100°F ±5°F (37.8°C ±3°C).
(1) Refer to figure 4-9 and in-
stall the condenser fan and motor assem-
bly .
Refer to figures 1-4 and 1-5 for
electrical connections.
(2) Refer to figure 4-4 and in-
stall the condenser cover and top rear
cover.
4-24.
Condenser Fan Motor Thermal Pro-
tector.
a.
General.
There are two automatic
reset thermal protectors on each of the
condenser fan motors.
Both thermal pro-
tectors are similar in appearance.
One
of the protectors provides overload pro-
tection for the high speed motor wind-
ings and the other provides overload
protection for the low speed motor wind-
ings.
b.
Test. Before removing a conden-
ser fan motor, test mode selector switch
and control circuit breaker (para 4-26)
and the fan motor high/low speed switch
(para 4-27) that control operation of
the condenser fan motor.
If electrical
control components or wiring that supply
power to the motor are not defective and
the motor does not operate, remove the
condenser fan and motor assembly (c.
below) and make the following tests:
b.
Removal.
(1) Test the high and low motor
winding thermal protectors, as in para
4-24c.
Replace a defective protector
(para 4-24c).
(1) Refer to paragraph 4-23 and re-
move the condenser fan and motor assem-
bly.
(2) Refer to figure 4-8 and remove
the thermal protector.
(2) With the high and low speed mo-
tor winding leads disconnected from the
thermal protectors, test for open or
grounded windings as follows:
c. Test.
Using a multimeter, test
for continuity across each terminal con-
nection.
If continuity is not indica-
ted, the thermal protector is defective
(a) Using a multimeter, test for
continuity across a combination of two
leads until each of the three high speed
winding leads is tested.
DO the same
for the three low speed winding leads.
If continuity is not indicated, the
winding is open and the motor should be
replaced.
and must be replaced.
d.
stall
Installation.
in-
4-17
(1) Refer to figure 4-8 and
the thermal protector.
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