Bryant Single Package Rooftop Electric Cooling/Gas Heating Units 580G - Manual (Page 25)

4. Turn motor jacking bolts to move motor mounting plate
left or right for proper belt tension. Refer to Table 2 for
proper belt tension.
5. Tighten nuts.
6. Adjust bolts and nut on mounting plate to secure motor
in fixed position. Recheck belt tension after 24 hours of
operation. Adjust as necessary.
C. Condenser-Fan Adjustment
1. Shut off unit power supply.
2. Remove fan guard.
3. Loosen fan hub setscrews.
4. Adjust fan height on shaft using a straightedge placed
across venturi and measure per Fig. 36.
5. Tighten setscrews and replace fan guard.
6. Turn on unit power.
V. GAS VALVE ADJUSTMENT
A. Natural Gas
The gas valve opens and closes in response to the thermostat
or limit control.
When power is supplied to valve terminals 3 and 4, the pilot
valve opens to the preset position. When power is supplied
to terminals 1 and 2, the main valve opens to its preset
position.
The regular factory setting is stamped on the valve body
(3.5 in. wg).
To adjust regulator:
1. Set thermostat at setting for no call for heat.
2. Turn field-supplied main gas valve to OFF position.
3. Remove 1 ⁄
8
-in. pipe plug from manifold. Install a water
manometer pressure-measuring device.
4. Set main gas valve to ON position.
5. Set thermostat at setting to call for heat.
6. Remove screw cap covering regulator adjustment screw
(See Fig. 37).
7. Turn adjustment screw clockwise to increase pressure
or counterclockwise to decrease pressure.
8. Once desired pressure is established, set thermostat set-
ting for no call for heat, turn off main gas valve, remove
pressure-measuring device and replace
1 ⁄
8
-in. pipe plug
and screw cap.
Fig. 35 — Belt Tension Adjustment
Fig. 36 — Condenser-Fan Adjustment
Fig. 37 — Gas Valve
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