Viking Designer DEDO530T, Service Manual

Page: 47 / 73

Diagnostics
© 2008 Viking Preferred Service
47
Cooling Fan
The cooling fan(s) on the “T” series wall oven are operated on 120 Volts. When the oven is turned on for any
cook cycle, the Cooling fan relay (K3) on the upper and lower relay will activate.
FIG A shows the LED in front
of the Fan relay activated. This will tell you that voltage is being sent to the relay coil. Fig B shows the power
wires coming off the relay board. As you can see there are 2 white w/black tracer wires connected to P5
on the board. L1 Power is sent to the Cooling fan motor.
The fan is controlled by the temperature of the RTD.
Whenever the oven is switched ON, the cooling fan will run through the LO speed relay. When the oven cavity
exceeds 375° F, the HI speed relay will engage. When the oven is switched off, the fan will continue to run if the
oven cavity is greater than 250° F. When the temp drops below that threshold, the fan will stop running.
NOTE:
Though the board is capable of producing two speeds, Viking only utilizes one speed .
Note:
When conducting the diagnostic program you can energize the Fan speed relay (K4) however you will
still get only High speed.
FIG C Below is a close-up of the actual fan motor connection. The white wire on the motor goes to the N
terminal on the main terminal block. The double white w/black tracer goes to P5 on the relay board.
Another connection on the cooling motor is the Hall sensor (See FIG D ).
The Hall Effect sensor is designed to sense when there is little or
no rotation in the cooling fan. The 3-wire Molex plug is connected
to fan motor as shown above.
FIG E shows the connection on the
Main Control board. On the Single oven and upper Double, the
connection is at PU4 on the board. On the lower double oven it is
connected to PL4.
Page 44 will cover how to test the hall sensor.
To N To P5
To
PU4
(upper) or
PL4
(Lower)
P2 P5 P3
P22
To Cooling
motor
Cooling fan
Relay
K3
K7 K6 K5 K4 K3 K2 K1