CONVEYOR OVEN SERVICE MANUAL
16
TROUBLESHOOTING
No / Low Heat
The oven uses a single heater assembly consisting of
three individual elements for a total of 6500 watts. The
element operation (L1) is controlled by a contactor. The
other side of the 208/240V power (L2) is controlled by
three independent SPST relays. The coils of these relays
are powered by the high limit switch which makes this
circuit energized at all times when power is connected
to the oven (unless the high limit has tripped). The On/
Off switch does not control this entire circuit.
32˚F (0˚C)
100.00
250˚F (121˚C)
146.49
300˚F (149˚C)
156.91
50˚F (10˚C)
103.90
350˚F (177˚C)
167.24
100˚F (38˚C)
114.68
400˚F (204˚C)
177.49
150˚F (65˚C)
125.37
450˚F (232˚C)
187.65
500˚F (260˚C)
197.71
212˚F (100˚C) 138.51
550˚F (288˚C)
207.69
RTD Chart OHM/Temp
Due to the design of the electrical circuit, the unit
is never truly in an “Off Mode”. When the power
switch is set to “standby” , electricity is still
present in the control panel. Always disconnect
the power from the wall before opening the
control panel
WARNING
Power Switch “On”
Amber LED Lit?
208/240V Through the
Contactor?
208/240V Across 29
and 28 at the Contactor
Coil?
208/240V Across 10
and 11 at Temp Controller?
Elements Correctly Wired
per Diagram?
RTD Checks OK?
See RTD Chart Below
208/240V Across
Switch Terminals?
208/240V Across Each
Element?
Replace Failed Temp
Control
Replace Failed Heater
Element
3 Amp Fuse Open?
High Limit Switch
Tripped?
Incoming Power at
the Contactor?
YES
NO
NO
YES
