Electrical Tests For Gas Dryers - Frigidaire Dryer Servicing

Section 3 Electronic Control Testing
Motor Protector Trip Time
When the motor is locked, the thermal protector must
open to shut off motor within 3 to 10 seconds.
This test also applies to the 50/60 Hz Motor when test
is conducted at 230VAC 60 Hz. Tests must be run at
120VAC (line voltage not to sag below this value when
the rotor is locked), unless specified otherwise.
NOTE
Tests must be run with a cold (ambient) motor. When
tested in the unit, a jumper harness will be needed to
bypass the software alarm for the motor not starting.
Without the jumper, the software will stop the cycle
within 3 seconds (before the thermal protector opens)
if motor movement is not detected.

Electrical Tests For Gas Dryers

Manifold Pressure
Connect manometer to pressure tap on gas valve.
During burner operation, manometer reading should be
between 2.9 and 4.0 inches of gage oil.
Flames Entering Drying Chamber
Block exhaust and inspect flame length. The flames
should not be entering the drying chamber.
Flash Back Into Burner
With exhaust blocked, inspect for flash back into burner
during ignition.
Flame Failure
Shut off manual gas valve to extinguish flame. Sensor
must shut off gas valve within 90 seconds.
Power Interruption
Interrupt power momentarily for 2 seconds, motor
should not continue to run when power is restored.
Valve should not open when power is restored until
ignition device is re-energized.
Carbon Deposit
Inspect heater housing and burner tube for carbon
deposits after testing.
Ignition Time
Time required for glow bar to light gas: 50 sec. max.
3-20
Ignition Power
Power required for glow bar to light gas: 550 - 850 Watt
Minimum Operating Voltage
Dryer and gas valve to function properly at 100 Volts.
Reduced Gas Pressure
Reduce gas pressure to 1.0 inch in gage oil. Stop and
then restart dryer. Allow gas ignition system to recycle
and check to see that ignition is obtained.
Static Pressure
Static pressure at the exhaust exit (when using a 100%
exhaust block), as measured by a manometer, shall be
1.6 inch of gage oil, minimum.
High Limit Thermostat Cycle Time Trip
Trip: Run the following test at room temperature. Set
the control board cycle time for 30 minutes and the heat
selection for regular fabrics (max heat setting). Place
a 100% exhaust block on the exhaust pipe. The dryer
door should be open for this test and the door switch
held closed by tape or similar means. The thermostat
must open (heater off) between 25 to 110 seconds.
Reset: When the exhaust block is removed and the
door closed (keep tape over door switch), the thermostat
must reset (heat on) within 120 seconds.
Thermal Limiter Trip Time
Run the following test at room temperature. Set the
Time Dry cycle for 30 minutes and the heat selection at
maximum setting. Place a 100% exhaust block on the
exhaust pipe. The dryer door should be open for this
test and the door switch held closed. The thermal
limiter should trip and shut the dryer off after 1 to 5
minutes of operation. To enable this test, the High
Limit Thermostat must be bypassed and NTC2 should be
removed from the heat duct.
NOTE
This test renders the thermal limiter inoperative, a new
thermal limiter must be installed after this test.