Blower Wheel Installation And Balancing; Fig. #9 .......................................... Oven Motor Assembly - Nu-Vu SUB-123 Owner's Manual

SERVICE AND REPLACEMENT GUIDE
E. Reconnect the Motor wires. Make sure all
connections are clean and tight.
F. Install the Blower Wheel on the Motor shaft. Set it at
the same distance as was measured before the Blower
Wheel was removed. Position the two set screws over
the flats on the Motor shaft and tighten them down
until snug. Recheck the position of the set screws over
the shaft flats and the measurement from the ceiling
of the Oven. Torque both set screws to 140
inch/pounds.
IMPORTANT: A loose Blower Wheel will cause an
immediate service problem and may damage the Oven
Motor.
G. Restore electrical power to the unit and test the Oven Motor for proper operation. Watch the Oven
Motor for any vibration. Any vibration or wobble in the Blower Wheel or motor must be corrected
immediately (refer to BLOWER WHEEL INSTALLATION AND BALANCING).
H. Replace the Outside Top and the Oven Element Cover. Make sure the ½" flange on the back of the
Element Cover fits into the guide strip welded to the ceiling of the Oven and that the Element
Cover is all the way back and tight to the ceiling. Tighten the thumbscrews securely.
I. Check to make sure the Blower Wheel clears the inside of the Element Cover. As a general rule
the Blower Wheel should be positioned about 3/16" from the inside of the Element Cover.

BLOWER WHEEL INSTALLATION AND BALANCING:

When installing a new Blower Wheel it is imperative that the Wheel be balanced correctly. An
improperly balanced Blower Wheel will cause premature failure of the Oven Motor.
The Blower Wheel should rotate under power in a counter-clockwise direction when viewed from the
open side of the Wheel. An up and down wobble may be noticeable when the wheel slows to a stop. A
wobble of less than 1/16" is acceptable; anything more must be corrected. The easiest method of
eliminating the wobble is to locate the narrowest distance between the Blower Wheel and the ceiling of
the Oven. Place this point toward you and gently pry the Blower Wheel down from the top. Repeat this
procedure until the wobble is eliminated. Check the tightness of the set screws on the Blower Wheel
hub; they should be torqued to 140 inch/pounds.
A new Blower Wheel may already have one or more weights attached; these have been installed by the
original manufacturer. If the Blower Wheel is not in balance when you test it please remove and save
these weights.
The Blower Wheel should now be ready for balancing.
CAUTION: DO NOT PLACE FINGERS NEAR THE BLOWER WHEEL WHILE IT IS STILL
TURNING, EVEN IF THE MOTOR IS TURNED OFF. THE MOVING VANES STILL HAVE
SUFFICIENT FORCE TO CAUSE SERIOUS INJURY!
A. Clip a weight to the inside of an air vane. Turn the Oven ON and depress the Door Micro Switch
[15]. Watch the Oven Motor [7] for any sign of vibration. Release the Micro Switch and allow the
Blower Wheel to come to a stop.
®
NU-VU FOOD SERVICE SYSTEMS
28
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SUB–123 OWNER'S MANUAL
Fig. #9– Oven Motor Assembly
MENOMINEE, MICHIGAN 49858-0035
(800) 338-9886