Amana RST Range User Manual


 
OPERATION AND SERVICE PROCEDURES
Electronic Range Control - ERC (Models w/One Piece Control)
49 RC231002 Rev. 3
controlled by the ERC, and a step down transformer with
two (2) secondary windings which convert the 120 VAC
input to 3.2 VAC filament voltage to power the ERC display
and 20.3 VAC drive voltage which the ERC uses to turn on
the bake and broil relays.
The oven temperature sensor is mounted in the oven
cavity and is connected to the J2 connector on the rear of
the ERC. As the oven temperature increases, the sensor
resistance also increases. The ERC converts this resis-
tance change to a corresponding temperature readout.
The ERC then cycles the bake/broil relays to maintain the
desired temperature setting.
The ERC is also capable of sensing certain failure condi-
tions which can occur in the temperature sensor, the self-
clean latch switch or the ERC itself. If the ERC senses a
failure, power will be removed from the bake/broil relays,
an alarm will sound, and a failure code will be displayed.
Each major component of the Electronic Range Control
System (ERC, temperature sensor), and related wire har-
ness must be tested prior to replacing the individual
component.
TESTING PROCEDURES
"DISPLAY" MODE - All segments of the display can be
checked by using the following sequence. NOTE: Clock
must previously be set for the time of day.
1. Press and hold the "CLOCK" button until "TIME" is
displayed and until "TIME" turns off.
2. Momentarily press "CANCEL" button until all display
segments are lit. Following the lighting of all of the
segments, the display will go through a "SALES
DEMONSTRATION" mode, displaying individual func-
tions. The "SALES DEMONSTRATION" mode will
show: (1) "BROIL", three horizontal segments and
the degree (°) symbol, (2) "OVEN", "TIME", and ":00",
(3) "CLEAN", "TIME", and "3:00", (4) "TIMER" and
":00", (5) time of day, (6) all segments and, (7)
"BAKE", three (3) horizontal segments and the de-
gree symbol. The program will continue to repeat
until the "CANCEL" button is pressed. The time of
day should then be displayed.
ERC FAILURE CODES AND WARNINGS
The Electronic Range Control is capable of detecting
certain failures within the ERC, the oven temperature
sensor and the self-clean latch switch.
The failure codes and warnings which may appear on the
display include F1 through F8, "DOOR" or "LOCK". A brief
description of the failure codes and warnings is listed
below:
F1 - Indicates a failed component in the ERC.
F2 - Sensor resistance too high. Check sensor resistance,
wire harness, and connections.
F3 - Open wire lead in sensor harness, bad harness/
sensor connections, or sensor resistance too high
(above 3300 ohms).
F4 - Sensor resistance too low (below 500 ohms). Check
for a short in sensor wire harness and check sensor
resistance.
F5 - Indicates a failed component in the ERC.
F6 - Indicates a failed component in the ERC or due to
fluctuations in 60 HZ power source.
F7 - Indicates a shorted or sticking contact in one or more
of the function control switches. Make sure the
function buttons are not binding on the control panel
glass - reposition the ERC and/or glass. Make sure
the function buttons spring outward after being de-
pressed.
F8 - Indicates a failed component in the ERC.
F9 - Door Latch Supervisory (Door latched):
Sounds alarm and resets control to non-cook mode if
the door latch supervisory logic fails for a sample
period of 2 seconds (while the door is latched).
Unlatching the door (if not locked) and Cancel Key
may reset the display code and audible. If the door is
locked (temp > 500°F) power must be removed until
the oven door can be unlatched.
"LOCK" LIGHT ON - If "LOCK" appears in the display
when the oven is not set in clean mode, indicates a
defective latch switch or shorted wire lead from the ERC
pin J2-4 or door is latched.
"DOOR" APPEARS IN DISPLAY IN BAKE/BROIL MODE
- This is an indication of a defective latch switch or a
shorted wire lead from the ERC pin J2-4 to ground, or door
is latched.
"DOOR" APPEARS IN DISPLAY DURING CLEAN MODE
- This is an indication of a defective latch switch or an open
wire lead from the ERC pin J2-4 to ground, or the door latch
has not been closed as required to initiate the clean cycle.
ELECTRONIC RANGE CONTROL TEMPERATURE
CALIBRATION
The ERC incorporates ± 35°F. calibration capabilities.
Follow the procedures below to calibrate the ERC:
1. Press and release the "BAKE TEMP." function but-
ton.