Relay Board Diagnosis - Viking RDSOE306SS Service Manual

Service Diagnostics and Procedures

Relay Board Diagnosis

Convection Fan
Locate the P4 connector and line break relay.
The P4 connector will have a Molex plug containing
4 wires:
(1) & (2) A blue wire jumper between terminals
REV and FWD
(3) orange/white wire–LO speed capacitor
(4) orange/black wire–HI speed capacitor
Convection Operation
The main power and speed are controlled by the
EOC by two relays (K5 and K7). K6 (directional is
not used on the RDSOE and RDDOE series ovens.
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.
Low Speed–Clockwise (FWD)
When closed, it sends power through K6 relay and
out the LO contact of the K7 relay.
The output from K5 is connected to the C (common
terminal) of K6. Because K6 is not used, both the
FWD and REV contacts are jumped together.
© 2012 Viking Preferred Service
Clockwise (FWD)–High Speed
K7 is the speed relay. It too is an SPDT relay. When
not energized, the LO circuit is energized through
the C terminal of the K7 relay. The N.O. terminal is
now closed resulting in the unit running at a higher
speed.
Testing Relay Board
Use a volt meter to measure voltage between
the orange/white (Low Speed) and the orange/ black
(High Speed) wire in the Molex plug and the neutral
terminal block.
The voltage should be 120 VAC. This will indicate
the K5 and K7 are functioning properly. With K7
energized, 120 volts should be measured between
neutral and the HI contact and when the relay is not
energized between neutral and the LO contact.
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