Venting

TYPICAL MOTOR/DRIVE INSTALLATION

MOTOR

MOTOR PULLEY

MOTOR SECURING

HARDWARE

MOTOR BASE

BELT TENSION ADJUSTING HARDWARE

PULLEY ALIGNMENT

BLOWER

PULLEY

MOTOR

PULLEY

FIGURE 7

B − Blower Belt Adjustment

Maximum life and wear can be obtained from belts only if the proper pulley alignment and belt tension are main- tained. Tension new belts after a 24 to 48 hour period of op- eration. This will allow the belt to stretch and seat in the grooves.

1 − Loosen belt adjusting hardware. See figure 7.

2 − To increase belt tension −

Move the motor base away from the blower housing.

To loosen belt tension −

Move the motor toward the blower housing. 3 − Tighten the belt adjusting hardware.

C − Check Belt Tension

Over-tensioning a belt shortens belt and bearing life. Check belt tension as follows:

1 − Measure span length X. See figure 8.

2 − Apply perpendicular force to the center of span (X) with enough pressure to deflect belt 1/64 inch for ev- ery inch of span length or 1.5mm per 100mm of span length.

Example: Deflection distance of a 40 inch span would be 40/64 inch or 5/8 inch.

Example: Deflection distance of a 400mm span would be 6mm.

3 − Measure the belt deflection force. For a used belt, the deflection force should be 5 lbs. (35kPa). A new belt deflection force should be 7 lbs. (48kPa).

A force below these values indicates an under-ten- sioned belt. A force above these values indicates an over-tensioned belt.

MEASURE BELT TENSION

FORCE

DEFLECTION 1/64 INCH PER INCH OF SPAN

OR 1.5 mm PER 100 mm OF SPAN

FIGURE 8

A vent adapter is factory-installed on each of the combus- tion air blower outlets. Modification of, or removal of the adapter(s) will cause unsafe unit operation and will void CSA unit certification. The vent adapter does not re- quire insulation.

The G24−200 units are classified as fan assisted Category I type furnaces when vertically vented according to the latest edition of ANSI Z21.47 Gas-fired Central Furnace Standard in the USA and the current standard CSA 2.3 Gas-fired Cen- tral Furnace in Canada. The definition of a fan assisted fur- nace is an appliance equipped with an integral mechanical means to either draw or force products of combustion through the combustion chamber and/or heat exchanger.

NOTE − Use these instructions as a guide. They do not su- persede local codes.

The vent sizing tables in this manual have been extracted from the Current edition of the National Fuel Gas Code (NFPA 54 / ANSI Z223.1) and are provided as a guide for proper vent installation. Proper application, termination, construction and location of vents must conform to local codes having jurisdiction. In the absence of local codes, the NFGC serves as the defining document in the U.S.A., while the CSA−B149 codes serve as the defining docu- ments in Canada.

Refer to the tables and the venting information contained in these instructions to properly size and install the venting system.

Install the first vent connector elbow a minimum of 6 in. (152mm) from the furnace vent outlet.

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