© 2010 Viking Preferred Service
41
Service Diagnostics and Procedures
Relay Board Diagnosis
Fan Relay
The unit is designed to operate a 2-speed cooling
motor. The DSOE305T and DDOE305T series
utilizes a one-speed motor so both the HI and LO
speeds are jumped together on the relay board.
However, both are jumped together so this change
is not noticed. If a fan error is shown, proceed with
the test shown below.
When the unit is switched on, voltage is sent to
both relay coils. A red LED (D9 D23) in front of
each coil verifies coil voltage is being sent to that
particular relay. This does not indicate however that
the relays are functioning.
When a cooking program is activated, the initial
cooling fan speed depends on the cycle selected.
When set for CONVECTION ROAST, CONVECTION
BROIL, HIGH BROIL, MEDIUM BROIL and SELF-
CLEAN, the fan runs at HIGH speed.
BAKE, CONVECTION BAKE, TRU CONVECTION
and LOW BROIL start at LOW speed and when the
oven temperature reaches 400˚F (204.5˚C), the EOC
switches to HIGH speed.
When the oven is turned off (cycle selector in
OFF position), the fan switches from high to low
when the temperature at the RTD drops below
375˚F (190.5˚C), and shuts off completely when the
temperature drops below 250˚F (121˚C).
To test
, disconnect power and disconnect P11
Molex plug. With voltmeter set for AC voltage,
check between neutral and the terminal. The
reading should be 120 VAC. If 0 volts are shown
and the red LED (D12 and/or D23) are illuminated,
the relay board should be replaced.
Fan–Hi Speed
The EOC is designed to run a 2-speed fan, however
the DDOE and DSOE models use a single speed fan
motor. When the EOC calls for fan operation, the
main fan relay K3 is energized and the fan operates.
When a program calls for low speed, the low
speed relay K4 is energized. Because both are tied
together, the results are the same.
With both relays engaged and voltmeter set for AC
voltage, check between neutral and each terminal.
The reading should be 120 VAC. If 0 volts is
measured and red LED (D9 D23) is illuminated, then
the relay board needs to be replaced.
K3
K4
LED
LED