Bake And Broil Ignitors - Amana AO27DG Service Manual

Test Procedures
!
WARNING
STOP TIME Button Test
10. Push STOP TIME button. Set stop time 10 minutes
past current time of day.
11. Push cook time button. Set cook time for five min-
utes. Display will show cook time. Meter should
indicate zero volts.
12. Clock counts down until reaching start time. Con-
tacts 11-12 close. Meter should indicate 120 VAC.
That voltage should be present at terminal 11 until
cook time reaches 0:00.
13. After cook time reaches 0:00, contacts 11-12
open. Meter should indicate zero voltage.
14. Silence buzzer by pushing minute timer button.
Clock/Timer Front View
CLEAN Button Test
15. Push clean. Display should show 3:00, "C" and
cooking symbol.
16. Contacts 11-12 should be closed. Meter should
indicate 120 VAC.
17. Turn time set knob counterclockwise until clean
time indicates one minute.
18. Let clean time count down to 0:00. Meter should
indicate 120 VAC at terminal 11 throughout clean
time period.
Clock/Timer Back View
19. When clean time reaches 0:00, zero volts should
be present at terminal 11 to neutral, indicating con-
tacts 11-12 are open.
Repeat the above voltage tests with voltmeter leads
attached to clock terminal 14 and any white or neutral
wire. Voltage at terminal 14 should be the same as at
terminal 11 in the preceding tests. If zero volts are indi-
cated in each test procedure, check voltage at termi-
nals 13 to neutral and 14 to neutral. If voltage is
present at terminals 13 and 14 to neutral or ground,
the clock contacts are not closing. Replace clock.
RA233001 Rev. 3
To avoid the risk of electric shock, personal injury or death, disconnect power To avoid the risk of electric shock, personal injury or death, disconnect power To avoid the risk of electric shock, personal injury or death, disconnect power
To avoid the risk of electric shock, personal injury or death, disconnect power To avoid the risk of electric shock, personal injury or death, disconnect power
before servicing, unless testing requires it. before servicing, unless testing requires it. before servicing, unless testing requires it. before servicing, unless testing requires it. before servicing, unless testing requires it.
24

Bake and Broil Ignitors

The bake and broil ignitors are mounted to the bake
and broil burners. They ignite the gas flowing into the
burner.
During bake and broil operations, current flows
through the ignitor, gas valve and thermostat to neu-
tral. As the ignitor heats up and starts glowing, its in-
ternal resistance decreases. This allows more current
to flow through the bake or broil circuit.
When the circuit current reaches approximately 3.2-
3.6 amps, the bimetal arm in the gas valve flexes,
opening the valve and allowing gas to flow to the
burner where it is ignited by the glowing ignitor. The
ignitors glow anytime the bake or broil burners are op-
erating and cycle on and off with the thermostat cy-
cling contacts.
Use the following procedure to check the ignitors for
continuity.
1. Disconnect power to oven.
2. Remove ignitor from burner. Disconnect ignitor
wiring.
3. Set ohmmeter to RX10 range. Attach one meter
lead to each ignitor lead.
4. A resistance of several hundred ohms may be indi-
cated. The amount of resistance may vary with
each ignitor. This test determines if the ignitor is
opened internally.
5. The ignitor may still have to be replaced even
though continuity is indicated and it glows when
the oven is set for a bake, broil or clean function.
The ignitor current may be measured more exactly by
testing with the oven operating. Use the following pro-
cedure to test the ignitor current with the oven operat-
ing.
1. Insert an ammeter in series with one lead of the
ignitor or any amprobe attached to the lead to
check the amount of current flowing through the
ignitor circuit.
2. Turn on oven and wait for ignitor to glow red. Meter
should indicate approximately 3.2-3.6 amps.
The same procedure may be used to bench test the
ignitor. Connect an AC jumper or test cord to the igni-
tor leads and follow the preceding procedure.