Repair manual

MT3855
1
CONVECTION BLOWER MOTORS
TO CHECK MOTOR ROTATION
1. Remove the back of the oven body and verify
proper motor rotation. (See FIGURE 1)
For motor placement, the direction of rotation is
viewed from the oven's rear and working from left
to right, beginning at the control box. In most
cases, the motor direction is referenced to the end
of the shaft (EOS). However, due to the vertical poĆ
sitioning of the motors in Mastertherm ovens, it is
more instructive to reference the end of the motor
(EOM) as looking from the rear of the oven. In
FIGURE 1 all directions are taken from EOM. The
correct rotation amperage draw is approximately 1
amp. If the measured amperage is less than .5,
check for proper motor rotation direction.
TO CHECK LOWĆLIMIT
1. Turn the oven on and let it heat up to approxiĆ
mately 200F (93C).
2. Shut the oven off. The blowers should come
back on in several seconds.
3. Wait for the blowers to shut off.
4. Once the blowers are off, turn the oven back
on. Press the ACT TEMP" key to verify that the
blowers shut off between 135F (57C) and
170F (77C). If the blowers do not shut off reĆ
fer to the Troubleshooting section page
NO TAG.
(Side view rotation of Blower Wheel)
(Top view rotation of Blower Wheel)
Motor #1
CCW
Motor #3
CCW
Control
Box
Control
Box
Motor #1 Motor #2
Motor #3
Blower
Motor
Slinger
Cooling
Blade
Blower
Motor
Slinger
Cooling
Blade
Motor #2
CCW
FIGURE 1