© 2012 Viking Preferred Service
27
Service Diagnostics and Procedures
Relay Board Diagnosis
With the relay board assembly accessed, the
following components can be diagnosed without
removal of the components:
Line Break Relay
The line break relay breaks the L2 side of line
voltage. As the relay is energized, the relay closes
and allows L2 to the convection, broil, and bake
element. Locate the line break relay on the relay
board. The relay will have a red wire and a yellow
wire connected to it. The red wire is L2 input from
the main power supply and the yellow wire supplies
L2 when the line break relay energizes.
When heating is selected by the control input,
voltage is sent to the line break relay coil. A red
LED (D30) in front of the coil verifies coil voltage is
being sent to the relay. This means that 12 VDC is
being sent to the relay coil. It does not indicate that
the relay contacts are closing. To check the relay
contacts, verify input voltage to the relay between
the red wire (L2) and (L1) black at the main terminal
block is 240 VAC.
Select a cooking program. When the relay contact
is closed (D30 LED at base of relay is illuminated
red) 240 VAC should be measured between the
yellow wire and (L1) black. If 0 VAC is measured,
disconnect power and remove the red and yellow
wire off the relay. With power applied, use an
Ohm meter to check for continuity between the
two relay contacts with the relay energized. If
infinite resistance (∞) is measured, this indicates
a bad relay and replacement of the relay board is
necessary.
Bake Element
Locate the P5 connector and the line break relay on
the relay board. The P5 connector will have a Molex
plug containing a blue and black wire. The blue wire
goes to the outer bake element terminal and the black
wire is L1 input from the main power supply.
With the power off and the Molex connector
removed from the P5 relay board connection, use an
Ohm meter to measure the resistance between the
blue wire in the Molex plug and the yellow wire from
the line break relay. This will measure the resistance
of the bake element and a reading of 23.7
Ω
should
be measured. If the element fails to read resistance,
repair or replace bake element as necessary
(see
Bake Element Disassembly).
Line Break Relay
