Wing Enterprises IOMWDF-1 D. Belt Tension and Adjustment, CAUTION Do not over tighten belts

D. Belt Tension and Adjustment

Belt tension is adjusted during the initial run-in and test periods at the factory. However, the belts are run as slack as possible to prevent excessive damage to the bearings, yet tight enough to prevent slippage.

It is necessary, therefore, to check belt tension during the first few months of operation, and to check for proper tension weekly during the first 60 days, after which 30-day check intervals are sufficient.

CAUTION: Turn off all power to the equipment before checking belt tensions.

CAUTION: Do not over tighten belts.

CAUTION: Do not attempt to tighten any belt or belts by changing the pitch of an adjustable pulley. This will change the air flow and fan speed.

Consult the factory if the fan speed must be changed.

Suggested Belt Tension Method

1.Check tension frequently during the first 24-48 hours of run-in operation. Ideal tension is the lowest tension at which the belt will not slip under peak load conditions. Over tensioning shortens belt and bearing life.

2.To properly tension a conventional V-belt drive,use the following procedure:

a.Measure the span length.

b.At the center of the span, apply a force perpendicular to the span to deflect the belt 1/64 inch for every inch of span length. For example, for a 40 inch span, apply a force that will deflect the belt 40/64 or 5/8 of an inch.

c.Compare the force you have applied with the values given in the table below. If the force is between the values for normal tension and 1 1/2 times normal tension, the belt tension should be satisfactory. If the belt tension is not within this range, it can be adjusted by loosening the motor mounting bolts and adjusting the position of the motor along its base.

NOTE: A new drive can be tightened to two times the minimum value shown to allow for normal drop in tension during the run-in period.

B Section Belt		Pounds	Pounds
small	Manufacturer &	Force for	Force for
pulley	Type Belt	Normal	11/2 times
diameter		Tension	Normal
range in			Tension
inches
3.4-4.2	Gates Hi-Power	4.4	6.6
4.4-4.6	Gates Hi-Power	4.9	7.4
5.8-8.6	Gates Hi-Power	5.8	8.7

Note: For recommendation of other types of belts, consult respective manufacturers.

F. Gaskets

Gaskets are used on doors, inspection covers, some filter racks, and some outdoor air dampers. Inspect gaskets periodically and repair or replace as required.

G. Heater

1.At least a yearly inspection is recommended for heating installations and more frequently for process applications in year-round operation. Your own experience is the best guide in determining frequency of inspection, but as a minimum, the following procedure should be followed:

a.Shut the system down totally, disconnecting or locking out power supply so there can be no accidental start-up during inspection.

b.Inspect the burner carefully, including upstream and downstream sides of mixing plates as well as burner body face. Note that complete burner assembly may have to be removed for proper inspection and cleaning. Any accumulation of scale or foreign material on either side of the mixing plates should be removed with a wire brush. Check visually that no holes in the mixing plates are blocked. If any burner ports are plugged, even partially, clear them with a piece of wire. Consult the factory for alternate procedures.

WARNING: Do not enlarge burner ports or performance may be drastically affected.

If any mixing plates are loose or missing fasteners, tighten or replace as necessary. Always use zinc plated or stainless fasteners.

The mixing plates on the burner may display “hairline” cracks. These cracks are normal and caused by thermal stresses occurring during com- bustion. The presence of these “hairline” cracks in no significant way affects the combustion efficiency or performance of the heater. Should a large opening develop, it may cause difficulties in cross ignition of flame across the face of the burner. If this does occur, the specific mixing plate or plates involved must be replaced.

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