Cooling Fan Relay; Convection Fan; Convection Operation; Clockwise (Fwd)-Low Speed - Viking RDSCE2305B Service Manual

Troubleshooting
To avoid risk of electrical shock, personal injury, or death, disconnect electrical power source to unit, unless test
procedures require power to be connected. Discharge capacitor through a resistor before attempting to service.
Ensure all ground wires are connected before certifying unit as repaired and/or operational.

Cooling Fan Relay

The oven control board is designed to
operate a two- speed cooling motor. The
oven utilizes a one-speed motor so both the
HI and LO speeds are jumped together on
the board. On initial startup, the oven control
board selects the fan power relay (K8) and
the LO speed (K9). When the oven temp
reaches 250˚F temp, the board will switch the
speed relay to HI. 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 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.
To test, connect power. With your meter set
for AC voltage, check between P1 white on
power supply board and the white/black wires
on P11 (refer to photo above). The reading
should be 120 VAC. If 0 volts are shown and
the red LED is lit, then the oven control board
is defective.
16
! WARNING

Convection Fan

Locate the P4 connector and line break relay.
The P4 connector will have a Molex plug
containing 4 wires:
(1) blue/black wire - FWD motor winding and
HI speed capacitor
(2) yellow/white wire - REV motor winding
(3) orange/white wire- LO speed capacitor
(4) orange/black wire - HI speed capacitor

Convection Operation

The convection system consists of a two-
speed, two- direction fan motor. The main
power, speed, and direction are controlled by
the oven control board by three relays (K5,
K6, and K7). K5 is the main control (Power)
relay and is an SPDT relay. It controls all
functions of the convection fan system. The
photo below shows the K5 relay energized.
Clockwise (FWD)–Low Speed
©2012 Viking Preferred Service