Rtd Temperature Sensor Testing; Oven Cavity Light Testing - Viking VGSO166 Service Manual

Service Diagnostics and Procedures

RTD Temperature Sensor Testing

The oven utilizes an RTD (Resistance Temperature
Detectors) to measure the temperature in the
oven cavity. As the temperatures rise and fall, the
resistance in the RTD changes. These changes are
interpreted by the thermostat timer, thus controlling
the bake and broil burners. As the temperature
rises, the resistance increases. Page 20 shows the
ratio of temperature to resistance.
RTD Sensor
To access the RTD sensor, slide the unit out 6 – 8",
remove the screws securing the upper trim, sensor
will be accessible on the right hand side. The RTD
has a Molex connector that once disconnected
allows testing of the sensor. With the sensor
disconnected and Volt-Ohm meter set to Ohms,
record the sensor resistance. At room temperature
the resistance should be approximately 1050 ohms.
If the resistance reading is zero ohms or extremely
high, replace the RTD. If the readings are within
range, ohm each wire to ground. If resistance is
present, then the RTD is grounded and the physical
wires must be checked for a grounded connection.
If the RTD resistance is within range and the wires
are not grounded, the RTD is functional and should
not be replaced.
© 2009 Viking Preferred Service

Oven Cavity Light Testing

Oven cavity lights
The oven utilizes 120 volt bulbs to illuminate
the oven cavity. The lights are switched on by
depressing the oven light switch on the control
panel.
To access the cavity lights, locate in the oven cavity.
Remove the lens. Remove the bulb from the socket
once cool. With Volt-Ohm meter set to ohms,
measure the resistance across the socket terminals
upper right approximately 29.5 Ω and lower right
approximately 28.8 Ω. If resistance is found, the
socket and wiring is good and the bulb should be
replaced. If no resistance is found, check the wiring
for a short or break. If wiring is good, the problem
lies in the socket.
®
21