JULY 30, 2014
10
3500 SERIES CONVECTION STEAMERS
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 ther-
mostatic switch. To test the switch, proceed as follows:
1. Disconnect the two wires connected to the thermo-
static switch terminals.
2. Connect an ohmmeter between the two terminals of
the switch.
3. Place the cooker into operation and observe ohmme-
ter 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 ob-
tained, the switch is defective.
4. Shut off cooker, disconnect ohmmeter leads, and re-
place wires on switch terminals.
BUZZER
If the buzzer does not sound at the termination of the op-
erator-selected timer setting (timer dial returned to “0 Min-
ute” position), the fault may be a defective buzzer. Buzzer
operation is verified using an AC volt-meter at buzzer coil
connections with input power on and selector switch and
coinciding timer dial set at the “0 Minute” position. If volt-
age is 120 volts, the fault is in the buzzer, which must be
replaced. If 120 volts is not present, the fault is in the wir-
ing or control components (timer or selector switch).
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 ther-
mostat, refer to cooking compartment thermostatic switch
section.
If the condenser thermostat functions correctly, but ei-
ther 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 opera-
tion. 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.
WIRING
All of the electrical components of the cooker (timers, in-
dicator lights, etc.) are connected to each other by wiring.
If all of the electrical components are operating correct-
ly (and the incoming power has been checked), but the
cooker fails to operate, the fault lies in the wiring.
Using an ohmmeter, wiring continuity between the con-
nections shown on the wiring diagram is readily verified.
This is best done in stages, removing only those wires
required for each continuity check. As each lead is re-
placed, it should be checked for evidence of corrosion,
and cleaned if necessary. All leads must be tightly at-
tached so as to provide a good electrical connection.