S-16A Checking Air Circulator Blower Motor (Psc); Checking Duct Static; Checking Temperature Rise - Amana GMSS9 Series Service Instructions Manual

SERVICING
S-16A CHECKING AIR CIRCULATOR BLOWER
MOTOR (PSC)
D ALL
ISCONNECT POWER BEFORE SERVICING.
1. Remove blower compartment door to gain access to
the circulator blower motor and integrated ignition con-
trol.
2. Discharge the capacitor on (PSC) motors. Disconnect
the motor wire leads from its connection point at the
integrated ignition control module and capacitor if ap-
plicable.
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 ob-
tained to ground, replace the motor.
5. After completing check and/or replacement of circula-
tor blower motor or induced draft blower motor, reinstall
blower compartment door.
6. Turn on electrical power and verify proper unit opera-
tion.
S-200 CHECKING DUCT STATIC
The maximum and minimum allowable external static pres-
sures 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 adjustment.
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 insuf-
ficient air that can cause excessive temperature rise, re-
sulting 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 (in-
clined manometer) to measure the static pressure 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 con-
ditioner coil or Electronic Air Cleaner is used in conjunc-
tion with the furnace, the readings must also include the-
ses components, as shown in the following drawing.
WARNING
4. Consult proper tables for the quantity of air.
If the total external static pressure exceeds the minimum
or maximum allowable statics, check for closed dampers,
registers, undersized and/or oversized poorly laid out duct
work.
SUPPLY
AIR
CUTAWAY OF DUCTWORK
AIR C O MMAN D
H I EF FICIEN C Y 8 0 GA S F UR N AC E
Amana
Elect ronic Air Cl eaner
Caution
High Vo l t a ge
To avoi d personal injury, wait 1 5
sec onds after de - en ergizing unit
before to uching u nit interio r .
Checking Static Pressure
S-201

CHECKING TEMPERATURE RISE

The more air (CFM) being delivered through a given fur-
nace, the less the rise will be; so the less air (CFM) being
delivered, the greater the rise. The temperature rise should
be adjusted in accordance to a given furnace specifica-
tions and its external static pressure. An incorrect tem-
perature rise may result in condensing in or overheating of
the heat exchanger. An airflow and temperature rise table
is provided in the blower performance specification sec-
tion. Determine and adjust temperature rise as follows:
1. Operate furnace with burners firing for approximately
ten minutes. Check BTU input to furnace - do not ex-
ceed input rating stamped on rating plate. Ensure all
registers are open and all duct dampers are in their
final (fully or partially open) position.
2. Place thermometers in the return and supply ducts as
close to the furnace as possible. Thermometers must
not be influenced by radiant heat by being able to "see"
the heat exchanger.
TO EXPOSE COIL
INCLINED
MANOMETER
RETURN
AIR
47