TurboChef SOTA NGO, Service Manual

Page: 49 / 85

28 OVEN SYSTEMS
Ethernet Extension Cable
The ethernet extension cable exits the oven at the
back panel and allows the oven to be connected to
a local network, in case the customer desires remote
programming and oven diagnostics reporting.
Fuses
The F1 and F2 fuses are 12-amp, ATMR, class CC.
The F3 fuse is 20-amp, ATMR.
The F1 fuse (via blue wire) and F2 fuse (via brown
wire) are designed to blow if an over-current
situation is encountered by the motor controller,
any cooling fan, either filament transformer, power
supply, or stirrer motor. The F3 fuse is designed to
blow in case of an over-current situation relative to
the microwave system (magnetron, high-voltage
transformer, diode, capacitor).
High Limit Thermostat
The high limit thermostat is a 250 VAC, 3-pole,
manual-reset thermostat with a trip point of 572ºF
(300ºC). The thermostat interrupts power to the
main convection heater in the event of an abnormal
condition. Reset the high-limit thermostat by
pressing the reset button (Figure 34).
Keypad
The keypad is a 8 x 11 matrix membrane switch.
For details on key functions, see page 7.
LED Light Ring (Sota only)
The LED light ring provides visual cues in regards
to oven operation, and counts down the final 30
seconds of each cook cycle.
Magnetron Thermostats
The magnetron thermostats are “open-on rise.”
They are designed to open at 270ºF (132ºC),
which triggers an F5 fault.
NOTE: The magnetron thermostats are wired in
series. If one opens, the control will switch off both
magnetrons until the open thermostat closes. The
thermostats are self-resetting.
Power Supply
The power supply outputs 24 VDC at 40 watts to
the control board and relays.
Relay - K1 Filament
The K1 relay is a 240 VAC, 24 VDC coil, 20 amp,
sealed single-pole relay. It switches power to the
filament transformers.
Relay - K2 Magnetron Cooling Fans
The K2 relay is a 240 VAC, 24 VDC coil, 20 amp,
sealed single-pole relay. It switches power to the
magnetron cooling fans when the magnetron
filaments are actuated. Power is switched off after
four minutes and fifteen seconds.
NOTE: The four-minute, fifteen-second timer
starts over each time the magnetron filaments are
actuated.
Relay - K3 Stirrer Motor
The K3 relay is a 240 VAC, 24 VDC coil, 20 amp,
sealed single-pole relay. It switches power to the
stirrer motor.
Relay - K6 Voltage
The K6 relay is a 240 VAC, 30 amp, three-pole,
double-throw, 24 VDC relay coil. Operational in
North America only, it switches between 208 and
240 VAC on the HV transformer and filament
transformer taps (depending on incoming voltage).
Through the voltage sensor, the oven defaults to the
240V position and switches to 208 if less than 222
volts is detected. 230V/400V international ovens
and all Japan models utilize the N.C. contacts of
the relay to power the microwave transformers. Figure 34: High-Limit Reset Button
Reset
Button