Bryant 580F Start-Up, Unit Preparation, II. Compressor Mounting, III. GAS Piping, XII. GAS Heat

START-UP

Use the following information and Start-Up Checklist on page CL-1 to check out unit PRIOR to start-up.

I. UNIT PREPARATION

Check that unit has been installed in accordance with these installation instructions and all applicable codes.

II. COMPRESSOR MOUNTING

Compressors are internally spring mounted. Do not loosen or remove compressor holddown bolts.

III. GAS PIPING

Check gas piping for leaks.

WARNING: Disconnect gas piping from unit when leak testing at pressure greater than 1/2 psig. Pres- sures greater than 1/2 psig will cause gas valve damage resulting in hazardous condition. If gas valve is sub- jected to pressure greater than 1/2 psig, it must be replaced before use. When pressure testing field- supplied gas piping at pressures of 1/2 psig or less, a unit connected to such piping must be isolated by man- ually closing the gas valve.

IV. REFRIGERANT SERVICE PORTS

Each refrigerant system has a total of 3 Schrader-type service gage ports. One port is located on the suction line, one on the compressor discharge line, and one on the liquid line. In addition, Schrader-type valves are located under- neath the low-pressure switches. Be sure that caps on the ports are tight.

V. COMPRESSOR ROTATION

It is important to be certain the compressors are rotating in the proper direction. To determine whether or not compres- sors are rotating in the proper direction:

1.Connect service gages to suction and discharge pres- sure fittings.

2.Energize the compressor.

3.The suction pressure should drop and the discharge pressure should rise, as is normal on any start-up.

If the suction pressure does not drop and the discharge pres- sure does not rise to normal levels:

1.Note that the evaporator fan is probably also rotating in the wrong direction.

2.Turn off power to the unit.

3.Reverse any two of the incoming power leads.

4.Turn on power to the compressor.

The suction and discharge pressure levels should now move to their normal start-up levels.

NOTE: When compressors are rotating in the wrong direc- tion, the unit will have increased noise levels and will not provide heating and cooling.

After a few minutes of reverse operation, the scroll compres- sor internal overload protection will open, which will

activate the unit’s lockout and requires a manual reset. Reset is accomplished by turning the thermostat on and off.

VI. INTERNAL WIRING

Check all electrical connections in unit control boxes; tighten as required.

VII. CRANKCASE HEATER

Crankcase heater(s) is energized as long as there is power to the unit and the compressor is not operating.

IMPORTANT: Unit power must be on for 24 hours prior to start-up. Otherwise, damage to compressor may result.

VIII. EVAPORATOR FAN

Fan belt and variable pulleys are factory-installed. See Tables 13-20 for fan performance data. Be sure that fans rotate in the proper direction. See Table 21 for air quantity limits. See Table 22 for static pressure information for acces- sories and options. See Table 23 for fan rpm at various motor pulley settings. See Tables 24 and 25 for evaporator fan motor data. To alter fan performance, see Evaporator Fan Performance Adjustment section on page 35.

NOTE: A 31/2-in. bolt and threaded plate are included in the installer’s packet. They can be added to the motor support channel below the motor mounting plate to aid in raising the fan motor.

IX. CONDENSER-FANS AND MOTORS

Condenser fans and motors are factory set. Refer to Condenser-Fan Adjustment section on page 36 as required. Be sure that fans rotate in the proper direction.

X. RETURN-AIR FILTERS

Check that correct filters are installed in filter tracks (see Table 1). Do not operate unit without return-air filters.

XI. OUTDOOR-AIR INLET SCREENS

Outdoor-air inlet screens must be in place before operating unit.

XII. GAS HEAT

Verify gas pressures before turning on heat as follows:

1.Turn off manual gas stop.

2.Connect pressure gage to supply gas pressure tap (see Fig. 14).

3.Connect pressure gage to manifold pressure tap on gas valve.

4.Turn on manual gas stop and set thermostat to HEAT position. After the unit has run for several minutes, verify that incoming pressure is 5.5 in. wg or greater, and that the manifold pressure is 3.3 in. wg. If manifold pressure must be adjusted, refer to Gas Valve Adjustment section on page 37.

5.After unit has been in operation for 5 minutes, check temperature rise across the heat exchangers. See unit informative plate for correct rise limits of the heat supplied. Air quantities may need to be adjusted to bring the actual rise to within the allowable limits.

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