Middleby Marshall PS220 Microwave Oven User Manual


 
74
B. PS360-series ovens
All PS360-series ovens are equipped with two blower motors.
All gas ovens have motors rated at 230V, single-phase.
All electric ovens built before 8/02 have three-phase
motors.
All electric ovens built 8/02 or later that operate on a
supply voltage of 208-240V have single-phase motors.
All electric ovens built 8/02 or later that operate on supply
voltages above 240V have three-phase motors.
Blower motors are protected by:
A built-in thermal overload protection device.
For ovens with single-phase blower motors: Two 9A
fuses. Fuse location is shown in Figure 35.
For ovens with three-phase blower motors: Three 5A
fuses. Fuse location is shown in Figure 36.
In addition, each motor contains a centrifugal safety switch
that prevents the burner/heating elements from activating if
either motor is not operating. See Blower Motor Centrifugal
Safety Switch on Page 80.
The blower wheel is directly connected to the motor shaft.
A heat slinger, also mounted on the motor shaft, helps to
keep heat away from the motor bearings. If the motor is
stopped when the temperature in the compartment is over
180°F/82°C, the bearings can be damaged.
Blower motors
Part Number Description
27381-0023 1 Ph, 1/3 hp (PS310, -314, -360, -360S)
27381-0024 3 Ph, 1/3 hp (PS310, -314, -360)
27381-0054 1 Ph, 1/4 hp (PS360Q)
27381-0075 1 Ph, 1/2 hp (PS360WB)
31432 1 Ph, 1 hp (PS360EWB, -WB70)
Blower wheels
Part Number Part Number
(clockwise) (counter-clockwise) Description
22523-0002 22523-0003 9-3/16 / 233mm dia. (PS310, -314,
-360, -360Q, -360S, -360WB)
35603 35604 9-1/8 / 232mm dia. (PS360EWB)
36014 36015 8-1/4 / 210mm dia. (PS360EWBQ)
31599 31600 9-7/8 dia. / 251mm (PS360WB70)
Other components
Part Number Description
27396-0005 Heat slinger
42400-0101 Blower wheel puller tool
1. Part number reference
Figure 35
Blower motor fuses - single-phase motors
Figure 36
Blower motor fuses - three-phase motors
Left motor
fuses - 9A
Right motor
fuses - 9A
Control
fuse - 5A
Left motor
fuses - 5A
Right motor
fuses - 5A
Control
fuse - 5A
Transformer fuses
(480V electric
ovens only)
2. Blower balancing
All blower wheels are balanced at the factory. Any
blower wheel found to be out of balance should be re-
placed. Vibration from an out-of-balance wheel can
cause poor baking and premature motor bearing fail-
ure. Note that vibrations can also be caused by other
sources, including defective motor bearings and loose
motor mounting bolts.
SECTION 3 - SERVICING COMPONENTS