Checking Air Circulator Blower Motor (Psc); Checking Duct Static - Goodman Amana AMH8 Service Instructions Manual

SERVICING
Two quick ways to test a capacitor are a resistance and
a capacitance check. Refer to the next two figures for
proper meter connections for the resistance and capaci-
tance testing of the capacitor.
NOTE: Use a capacitor tester to check capacitance.
S-15A Resistance Check
VOLT / OHM
METER
Testing Capacitor Resistance
HIGH VOLTAGE
D ALL
ISCONNECT POWER BEFORE SERVICING OR
M
INSTALLING THIS UNIT. ULTIPLE POWER SOURCES MAY
F
BE PRESENT. AILURE TO DO SO MAY CAUSE PROPERTY
DAMAGE, PERSONAL INJURY OR DEATH.
1. Remove blower compartment door to gain access to
capacitor.
2. Discharge capacitor and remove wire leads.
3. Set an ohmmeter on its highest ohm scale and con-
nect the leads to the capacitor.
a. Good Condition - indicator swings to zero and
slowly returns toward infinity.
b. Shorted - indicator swings to zero and stops
there - replace.
c. Open - no reading - replace. Reverse leads.
Check again no reading - replace.
d. Reverse leads and recheck.
S-16 CHECKING AIR CIRCULATOR BLOWER MOTOR
(PSC)
WARNING
D ALL
ISCONNECT POWER BEFORE SERVICING.
1. Remove blower compartment door to gain access to
the circulator blower motor and integrated ignition
control.
52
WARNING
2. Discharge the capacitor on (PSC) motors. Disconnect
the motor wire leads from its connection point at
the integrated ignition control module and capaci-
tor if applicable.
3. Using a ohmmeter, test for continuity between each
of the motor leads.
4. Touch one probe of the ohmmeter to the motor frame
(ground) and the other probe in turn to each lead.
If the windings do not test continuous or a reading is
obtained to ground, replace the motor.
5. After completing check and/or replacement of cir-
culator blower motor or induced draft blower mo-
tor, reinstall blower compartment door.
6. Turn on electrical power and verify proper unit op-
eration.
WARNING
D ALL
ISCONNECT POWER BEFORE SERVICING.
S-200 CHECKING DUCT STATIC
The maximum and minimum allowable external static
pressures are found in the specification section. These
tables also show the amount of air being delivered at a
given static by a given motor speed or pulley adjust-
ment.
The furnace motor cannot deliver proper air quantities
(CFM) against statics other than those listed.
Too great of an external static pressure will result in
insufficient air that can cause excessive temperature
rise, resulting in limit tripping, etc. Whereas not enough
static may result in motor overloading.
To determine proper air movement, proceed as follows:
1. With clean filters in the furnace, use a draft gauge
(inclined manometer) to measure the static pres-
sure of the return duct at the inlet of the furnace.
(Negative Pressure)
2. Measure the static pressure of the supply duct. (Posi-
tive Pressure)
3. Add the two (2) readings together for total external
static pressure.
NOTE: Both readings may be taken simultaneously and
read directly on the manometer if so desired. If an air
conditioner coil or Electronic Air Cleaner is used in con-
junction with the furnace, the readings must also in-
clude theses components, as shown in the following
drawing.