Bryant Low Charge Cooling, Perfect Humidity System Charging, Unit 581B

Fig. 44 — Cleaning Condenser Coil

Fig. 45 — Propping Up Top Panel

Fig. 46 — Separating Coil Sections

UNIT 581B	FAN HEIGHT — “A” (in.)
036-060 and 072 (208/230 V)	2.75
072 (460 and 575 V)	3.50

Fig. 47 — Condenser-Fan Adjustment

A. No Charge

Use standard evacuating techniques. After evacuating sys- tem to 500 microns, weigh in the specified amount of refrig- erant. (Refer to Table 1 and unit information plate.)

B. Low Charge Cooling

Using Cooling Charging Charts, Fig. 48-51, vary refrigerant until the conditions of the charts are met. Note the charging charts are different from type normally used. Charts are based on charging the units to the correct superheat for the various operating conditions. Accurate pressure gage and temperature sensing device are required. Connect the pressure gage to the service port on the suction line. Mount the temperature sensing device on the suction line and insulate it so that outdoor ambient temperature does not affect the reading. Indoor-air cfm must be within the normal operating range of the unit.

C. Perfect Humidity™ System Charging

The system charge for units with the Perfect Humidity system is greater than that of the standard unit alone. The charge for units with this option is indicated on the unit nameplate drawing. Also refer to Fig. 52-55. To charge systems using the Perfect Humidity Dehumidification system, fully evacuate, recover, and recharge the system to the unit information plate specified charge level.

To check or adjust refrigerant charge on systems using the Per- fect Humidity Dehumidification system, charge per Fig. 52-55.

NOTE: When using the charging charts, it is important that only the subcooling/reheat dehumidification coil liquid line solenoid valve be energized. The subcooling/reheat dehumid- ification coil liquid line solenoid valve MUST be energized to use the charging charts and the outdoor motor speed control- ler jumpered to run the fan at full speed.

The charts reference a liquid pressure (psig) and tempera- ture at a point between the condenser coil and the subcooling/reheat dehumidification coil. A tap is provided on the unit to measure liquid pressure entering the subcooling/ reheat dehumidification coil.

IMPORTANT: The subcooling mode charging charts (Fig. 52-55) are to be used ONLY with units having the optional Perfect Humidity subcooling option. DO NOT use standard charge (Fig. 48-51) for units with Perfect Humidity system, and DO NOT use Fig. 52-55 for standard units.

D. To Use Cooling Charging Chart, Standard Unit

Take the outdoor ambient temperature and read the suction pressure gage. Refer to charts to determine what suction tem- perature should be. If suction temperature is high, add refrig- erant. If suction temperature is low, carefully recover some of the charge. Recheck the suction pressure as charge is adjusted. Example (Fig. 50):

Outdoor Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 F Suction Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .70 psig Suction Temperature should be . . . . . . . . . . . . . . . . . . . . 48 F (Suction temperature may very ± 5 F.)

If charging device is used, temperature and pressure read- ings must be accomplished using the charging charts.

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