5-5
SECTION 5 TROUBLE-SHOOTING
5.4.5 Steam Solenoid Valve
When either inlet solenoid valve fails to operate, the fault
may be a defective coil. A defective coil is found using an
AC volt-meter to check the voltage at the coil wire
terminals, with the cooker compartment operating in either
constant steam or 60-minute timer mode. If voltage of
120 volts is present and the coil fails to open the valves,
the fault is in the valve coil. Defective valve coils are not
separately replaceable, requiring complete valve
replacement.
5.4.6 Indicator Lights
If the cooker compartment functions correctly, with the
single exception that the indicator light fails to light during
operation, the fault is a defective indicator light. A “burned
out” or defective light is verified by using an AC volt-meter
at the leads, with input power on the selector switch in the
correct position for that timer, the timer set, and the door
latches closed. If 120 volts is present, the fault is in the
indicator light and requires replacement. If 120 volts is not
present, the fault is in the wiring or control components
(selector switch, timer, or door switch).
5.4.7 Cooking Compartment
Thermostatic Switch
A thermostatic switch included in the circuit for the timer
motor delays timer operation until steam flowing into the
compartment satisfies the temperature-actuated switch
device. If a timer motor fails to operate within about one
minute after the indicator light comes on (with cooker
compartment empty), the cause may be a defective
thermostatic switch. To test the switch, proceed as follows:
1. Disconnect the two wires connected to the thermostatic
switch terminals.
2. Connect an ohmmeter between the two terminals of the
switch.
3. Place the cooker into operation and observe ohmmeter
dial. Within one minute of operation, the switch contacts
close automatically to register a zero ohm reading on
the dial. If a zero ohm reading is not obtained, the
switch is defective.
4. Shut off cooker, disconnect ohmmeter leads, and
replace wires on switch terminals.
5.4.8 Buzzer
If the buzzer does not sound at the termination of the
operator-selected timer setting (timer dial returned to “0-
Minute” position), the fault may be a defective buzzer.
Buzzer operation is verified using an AC volt-meter at the
buzzer coil connections with input power on and selector
switch and coinciding timer dial set at the “0-Minute”
position. If voltage is 120 volts, the fault is in the buzzer,
which must be replaced. If 120 volts is not present, the
fault is in the wiring or control components (timer or
selector switch).
5.4.9 Cold Water Condenser Circuit
If during cooker operation steam exits from the drain line
opening (located in lower boiler compartment) and the
condensing system fails to operate, as evidenced by
repeated discharge of water from the drain line, the
condensing circuit is malfunctioning. The failure can be
caused by a defective condenser thermostat or cold water
solenoid coil, or by wiring failure. To test condenser
thermostat, refer to Subsection 5.4.8.
If the condenser thermostat functions correctly, but either
of the cold water solenoid valves fails to operate, the
cause might be a faulty valve coil. A defective coil is found
using an AC volt-meter to check the voltage at the coil wire
terminals with the cooker compartment in operation. If
voltage of 120 volts is present and the valve fails to open,
the fault is in the valve coil. Defective valve coils are
separately replaceable.
5.4.10 Wiring
All of the electrical components of the cooker (timers,
indicator lights, etc.) are connected to each other by wiring
shown in Figure 5-1. If all of the electrical components are
operating correctly (and the incoming power has been
checked), but the cooker fails to operate, the fault lies in
the wiring.
Figure 5-1 is a diagram that shows all terminals and
interconnections within the electrical circuits. All numbered
terminals are identified and all leads number-coded as
shown. Connections can be easily removed. Figure 5-2
shows the same information schematically and is an aid in
isolating circuits for testing.
Using an ohmmeter, wiring continuity between the
connections shown on the wiring diagram (Figure 5-1) is
readily verified. This is best done in stages, removing only
those wires required for each continuity check. As each
lead is replaced, it should be checked for evidence of
corrosion, and cleaned if necessary. All leads must be
tightly attached so as to provide a good electrical
connection.