Page 15
STEP 2 Confirm DC voltage output on compressor
solenoid plug
A
− Compressor solenoid plug
WITH
built in full wave−
rectifier (LSOM I) that converts 24 volt AC into 24 volt DC
power. See Table 1 for units equipped with the LSOM I.
1. Shut power off to outdoor unit.
2. Supply 24 volts AC control voltage to the wire ends of
the full wave rectifier plug. Listen for a click" as the so-
lenoid is energized. See figure 14.
compressor
solenoid fusite
terminals
compressor
fusite
terminals
meter
rectifier plug leads
apply 24vac
FIGURE 14
3. Unplug the full wave rectifier plug from the fusite con-
nection on the compressor.
4. Turn the low voltage power back onto the unit. Supply
24VAC to the wires of the full wave rectifier plug. Set
volt meter to DC volts and measure the DC voltage at
the female connector end of the full wave rectifier plug.
The DC voltage reading should be 1.5 to 3 volts lower
than the input voltage to the plug wire leads. (EX: Input
voltage is 24VAC output voltage is 22VDC).
See figure 15.
meter
rectifier plug leads
compressor
fusite
terminals
solenoid
fusite
terminals
compressor
apply 24vac
FIGURE 15
If the above checks verify that the solenoid plug is pro-
viding power to cycle into high capacity operation, contin-
ue to step 3 to determine if problem is with solenoid coil
in compressor
STEP 3 Confirm internal unloader solenoid has prop-
er resistance
1. Shut all power off to unit (main and low voltage)
2. Unplug the molded plug from the compressor solenoid
2−pin fusite.
3. Using a volt meter set on the 200 ohm scale
Replace the Compressor under these conditions:
Bad Solenoid
a. Measure the resistance at the 2−pin fusite. The resist-
ance should be 32 to 60 ohms depending on compressor
temperature. If no resist ancereplace compressor.
b. Measure the resistance from each fusite pin to ground.
There should
not be
continuity to ground. If solenoid coil
is grounded, replace compressor.
Good Solenoid
a. Seals not shifting, replace compressor
b. Slider ring not shifting, replace compressor.
C − Outdoor Fan Motor
All units use single−phase PSC fan motors which require a run
capacitor. In all units, the condenser fan is controlled by
the compressor contactor.
ELECTRICAL DATA tables in this manual show specifi-
cations for condenser fans used in SPB*H4’s.
Access to the condenser fan motor on all units is gained
by removing the four screws securing the fan assembly.
See figure 16. The grill fan assembly can be removed
from the cabinet as one piece. See figure 17. The con-
denser fan motor is removed from the fan guard by re-
moving the four nuts found on top of the grill. See figure
17 if condenser fan motor replacement is necessary.
Make sure all power is disconnected before
beginning electrical service procedures.
DANGER
FIGURE 16
Remove
screws
Remove
screws
ALIGN FAN HUB FLUSH WITH END OF SHAFT
FIGURE 17
NUTS (4)
