Electric Oven Service Manual

To From Description Expected Resistance
White Grey Winding (A-B)
215-217 W
White Black Winding (A-C)
215-217 W
Grey Black Winding (B-C)
215-217 W
Black, Brown, or
Blue
Green
Windings to
chassis
Open
Figure 30: Conveyor Motor Ohm Chart
24 OVEN SYSTEMS
3. If the resistance readings are correct,
reconnect the motor wiring and then apply
line voltage to the unit and check for
voltage applied to the motor windings.
4. If no voltage is present, ensure the CMSC is
operating properly (see below).
5. If CMSC is operating properly, inspect the
wire harness for damage or shorts.
6. If the wire harness is intact and undamaged,
and the CMSC is operating properly, the
gear drive is damaged or defective and must
be replaced (page A-8).
Gear Drive (Conveyor Motor) Speed
Controller (CMSC)
The CMSC converts single-phase line voltage
to a three-phase output. The speed of the gear
drive is controlled by the frequency output of
the CMSC. The CMSC receives an input
voltage (0-10 VDC) from the control board
and adjusts the frequency output to the gear
drive.
Testing Procedure
WARNING: Capacitors within the CMSC
can retain charge after power is removed.
Exercise extreme caution when handling the
terminals.
WARNING: DO NOT connect incoming
AC power to output terminals U, V, or W.
This will seriously damage the Conveyor
Motor Speed Controller.
1. Ensure that no faults appear on the display
of the CMSC during oven operation. The
control will display the frequency output if
the system is operating correctly.
2. Check the input voltage on terminals L1 &
L2 and the DC voltage input on terminals
0V & AI (0.1-10 VDC).
3. Check ohms of motor (Figure 30).
4. If no voltage is present, inspect the wire
harness for damage or shorts (page 45).
5. If wire harness is intact and undamaged,
the CMSC is damaged or defective and
must be replaced.
ºF 0º +20º +40º +60º +80º +100º +120º +140º +160º +180º +200º
0º
90.03W 97.39W 101.74W 106.07W 110.38W 114.68W 118.97W 123.24W 127.50W 131.74W 135.97W
+200º
135.97W 140.18W 144.38W 148.57W 152.74W 159.90W 161.04W 165.17W 169.29W 173.39W 177.47W
+400º
177.47W 181.54W 185.60W 189.64W 193.67W 197.69W 201.69W 205.67W 209.64W 213.60W 217.54W
+600º
217.54W 221.47W 225.38W 229.28W 233.17W 237.04W 240.90W 244.74W 248.57W 252.38W 256.18W
ºC 0º +10º +20º +30º +40º +50º +60º +70º +80º +90º +100º
0º
100.00W 103.90W 107.79W 111.67W 115.54W 119.40W 123.24W 127.07W 130.89W 134.70W 138.50W
+100º
138.50W 142.29W 146.06W 149.82W 153.58W 157.31W 161.04W 164.76W 168.46W 172.16W 175.84W
+200º
175.84W 175.91W 183.17W 186.82W 190.45W 194.07W 197.69W 201.29W 204.88W 208.45W 212.02W
+300º
212.02W 215.57W 219.12W 222.65W 226.17W 229.67W 233.17W 236.65W 240.13W 243.59W 247.04W
Figure 29: Temperature/Resistance Relationship Class B. Resistance @ 0ºC = 100.0, Alpha = 0.003850