Electric Oven Service Manual

OVEN SYSTEMS
Accessing Parameters
WARNING: DO NOT perform this
procedure unless instructed by
TurboChef.Changing the parameters to
other than those preset by TurboChef can
damage critical oven components.
NOTE: “Motor Rated Speed” (07) is RPM of
motor before gearbox, not after.
1. Open the right end bell (page 1).
2. Locate the CMSC (page A-8).
3. Press the
M key.
4. Use the and keys to navigate the
parameters.
5. Press the
M key to access the parameter
shown on the CMSC display.
6. Use the and keys to manipulate the
parameter.
7. Press the M key to return to the parameter
selection.
8. Repeat steps 4-7 to manipulate other
parameters as needed.
The Blower System
This section contains information about and
testing procedures for the following
components:
-Blower Motor
-Blower Motor Speed Controller (BMSC)
Blower Motor
The main blowers are 3400 RPM, 3-phase
blower motors. The speed of the blower motor
is controlled by the voltage frequency applied to
the motor windings from the blower motor
speed controller (BMSC).
Testing Procedure
1. Disconnect line voltage from the unit.
2. Take a resistance reading of the motor
windings and use Figure 31 to verify the
resistance readings are correct.
3. If the resistance readings are correct,
reconnect 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 BMSC is
operating properly (see below).
5. If BMSC is operating properly, inspect the
wire harness for damage or shorts (page 45).
6. If wire harness is intact and undamaged and
the BMSC is operating properly, the blower
motor is damaged or defective and must be
replaced (page A-8 = lower, A-12 = upper).
Blower Motor Speed Controller (BMSC)
The BMSC converts single-phase line voltage
(208-240 VAC) to a three-phase output. The
speed of the blower motor is controlled by the
frequency output of the BMSC. The BMSC
receives an input voltage (0-10 VDC) from the
I/O control board and adjusts the frequency
output to the blower motor.
Testing Procedure
CAUTION: Capacitors on the BMSC
may retain charge after power is removed.
To discharge capacitors for further safety,
short B+ and B- together.
WARNING: DO NOT connect
incoming AC power to output terminals
U, V, or W or terminals B+ or B-. This
will seriously damage the BMSC.
1. Ensure that no faults appear on the display
during the operation of the BMSC. The
control will display the frequency output if
the system is operating correctly.
25
To From Description Expected Resistance
Blue Brown Winding (A-B)
5.1-5.5 W
Blue White Winding (A-C)
5.1-5.5 W
Brown White Winding (B-C)
5.1-5.5 W
Blue, Brown, or
White
Green
Windings to
chassis
Open
Figure 31: Blower Motor Ohm Chart (Motor Windings)