Magnetron Cooling Fan; Magnetron Thermostats; Power Supply, 12 Vdc; Power Supply, 24 Vdc - TurboChef Residential Single and Double Wall Oven Service Manual

5.10 OVEN SYSTEMS

Magnetron Cooling Fan

Th e magnetron cooling fans supply air to the
magnetrons. For Gen 1 ovens, they are actuated by
the K5 relay. For Gen 2 ovens, they are actuated by
relay 4 on the relay board (RBJ19-1). At the end of a
microwave cook cycle, the cooling fans will continue
to operate for an additional 2 minutes (on older ver-
sions of the control software, the magnetron cooling
fans run for an additional 5 minutes).

Magnetron Thermostats

Th e magnetron thermostats are wired in-series with
the input voltage of the HV transformers. Th ey open
at 280°F (138°C).

Power Supply, 12 VDC

Th e 12 VDC power supply supplies power to the
halogen oven lights.

Power Supply, 24 VDC

Th e 24VDC power supply supplies voltage to the
control board (and relay board for Gen 2 ovens).
Relay Board (Gen 2 Only)
Gen 2 ovens contain a relay board consisting of the
fuses (page 5.9), clock transformer, and all relays
described below. If any of these components fail,
except the fuses, the entire relay board must be
replaced. See page 7.7 for a schematic with test point
locations.
- Relay 1: Monitor
- Relays 2 and 3: HV transformers
- Relay 4: Magnetron cooling fan
- Relay 5: Door lock, upper left
- Relay 6: Door lock, upper right
- Relay 7: Cooling fan, upper
- Relay 8: Stirrer motor
- Relay 9: Door light, upper
- Relay 10: Door lock, lower
- Relay 11: Cooling fan, lower
- Relay 12: Convection fan
- Relay 13: Door light, lower
- Relay 14: Pre-heater

Relay - K2 Monitor (Gen 1 Oven)

Th e K2 relay is a 30 amp, double-pole, double-
throw, class F, 24 VDC relay coil. It is used in the
magnetron circuit along with the K3 and K4 relays.
If the door is opened during a cook cycle, and the
K3 or K4 relays are still closed due to a door switch
failure, this relay will cause L1 and L2 voltage to
short circuit and blow the 20-amp fuse. Th e system
is designed to protect the user in the case of a
door switch failure. Th e K2 relay coil is supplied
with 24 VDC power except when the door is open
or oven power is disconnected.

Relay - K3 T1 HV Transformer (Gen 1 Oven)

Th e K3 relay is a 30 amp, double-pole, double-
throw, class F, 24 VDC relay coil. Th is relay sends L1
voltage to the T1 transformer.

Relay - K4 T2 HV Transformer (Gen 1 Oven)

Th e K4 relay is a 30 amp, double-pole, double-
throw, class F, 24 VDC relay coil. Th is relay sends L1
voltage to the T2 transformer.

Relay - K5 Mag Cooling Fan (Gen 1 Oven)

Th e K5 relay is a 30 amp, double-pole, double-
throw, class F, 24 VDC relay coil. Th is relay activates
the magnetron cooling fan during and after
magnetron operation.

Relay - K6 Right Side Door Lock (Gen 1 Oven)

Th e K6 relay is a 30 amp, double-pole, double-
throw, class F, 24 VDC relay coil. Th is relay controls
the right side door lock motor.

Relay - K7 Left Side Door Lock (Gen 1 Oven)

Th e K7 relay is a 30 amp, double-pole, double-
throw, class F, 24 VDC relay coil. Th is relay controls
the left side door lock motor.

Relay - K8 Preheat (Gen 1 Oven)

Th e K8 relay is a 30 amp, double-pole, double-
throw, class F, 24 VDC relay coil. Th e K8 relay
controls the L1 voltage to the Speedcook oven's
preheat element. When the CookWheel is turned to
begin the selection process, the control board sends