Assessments - 1, GPA: 5
(
)
)
|
Facilidade de uso
Deduct filter and electric heater pressure drops to obtain static pressure available for ducting. NOTES: 1. Do not operate the unit at a cooling airflow that is less than 350 cfm for each 12,000 Btuh of rated cooling capacity. Evaporator coil frosting may occur at airflows below this point. 2. Dashes indicate portions of table that are beyond the blower motor capacity or are not recommended. 3. Deduct 10% for 208v. The charging label and the tables shown refer to system temperatures and pressures in cooling mode only. A refrigerant charging label is attached to the outside of the service access door. If charge level is suspect in Heating mode, reclaim all refrigerant and charge to nameplate amount. (This information may be obtained from the physical data table also.) IMPORTANT: When evaluating the refrigerant charge, an indicated adjustment to the specified factory charge must always be very minimal. If a substantial adjustment is indicated, an abnormal condition exists somewhere in the cooling system, such as insufficient airflow across either coil or both coils. REFRIGERANT CHARGE — The amount of refrigerant charge is listed on the unit nameplate and /or the physical data table. Refer to the Refrigeration Service Techniques Manual, Refrigerants Section. NO CHARGE — Check for leak. Use standard evacuating techniques. After evacuating system, weigh in the specified amount of refrigerant (refer to system data plate). LOW CHARGE COOLING — Use Cooling Charging Charts (Figs. 23-35). Vary refrigerant until the conditions of the chart are met. Note that charging charts are different from type normally used. Charts are based on charging the units to correct superheat for the various operating conditions. Accurate pressure gage and temperature sensing devices 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 the outdoor ambient does not effect the reading. Indoor air CFM must be within the normal operating range of the unit. TO USE COOLING CHARGING CHARTS — Take the outdoor ambient temperature and read the suction pressure gage. Refer to the chart to determine what the suction temperature should be. NOTE: If the problem causing the inaccurate readings is a refrigerant leak, refer to Check for Refrigerant Leaks section. 18 INDOOR AIRFLOW AND AIRFLOW ADJUSTMENTS For heating and cooling operation, the recommended airflow is 350 to 450 cfm for each 12,000 Btuh of rated cooling capacity. for units with optional electric heat, the airflow must not be reduced below the levels stated in Tables 2A and 2B. Airflow can be changed by changing the lead connection of the blower motor. Unit 50JS and JX three-speed motors (except sizes JS 018 and JX 030) are factory wired for low speed operation. Unit 50JX 030 is factory wired for medium speed. Unit 50JS 018 has a two-speed motor wired for low speed. For 208/230-v Motors:—The motor leads are color-coded as follows: Fig. 23—Cooling Charging Chart, 50JS 018 Units C00026 SUCTION LINE PRESSURE (KILOPASCALS)SUCTION LINE PRESSURE (PSIG) -7 -1 4 10 16 21 27 SUCTION LINE TEMPERATURE (°F) SUCTION LINE TEMPERATURE (°C) 689 620 551 483 414 345 276 207 100 90 80 70 60 50 40 30 (018) 60HZ CHARGING CHART 20.0 30.0 40.0 50.0 60.0 70.0 80.0 OUTDOOR TEMP ° F ° C 115 46 125 52 45 7 55 13 65 18 75 24 95 35 105 41 85 29 50JS500087 Fig. 24—Cooling Charging Chart, 50JS 024 Units C00027 SUCTION LINE PRESSURE (KILOPASCALS)SUCTION LINE PRESSURE (PSIG) -7 -1 4 10 16 21 27 SUCTION LINE TEMPERATURE (°F) SUCTION LINE TEMPERATURE (°C) 758 689 620 551 483 414 345 276 110 100 90 80 70 60 50 40 (024) 60HZ CHARGING CHART 20.0 30.0 40.0 50.0 60.0 70.0 80.0 OUTDOOR TEMP ° F ° C 115 46 125 52 45 7 55 13 65 18 75 24 95 35 105 41 85 29 50JS500088 Fig. 25—Cooling Charging Chart, 50JS030 Units C00028 SUCTION LINE PRESSURE (KILOPASCALS)SUCTION LINE PRESSURE (PSIG) -7 -1 4 10 16 21 27 SUCTION LINE TEMPERATURE (°F) SUCTION LINE TEMPERATURE (°C) 689 620 551 483 414 345 276 207 100 90 80 70 60 50 40 30 (030) 60HZ CHARGING CHART 20.0 30.0 40.0 50.0 60.0 70.0 80.0 OUTDOOR TEMP ° F ° C 115 46 125 52 45 7 55 13 65 18 75 24 95 35 105 41 85 29 50JS500089 Fig. 26—Cooling Charging Chart, 50JS 036 Units C00029 SUCTION LINE PRESSURE (KILOPASCALS)SUCTION LINE PRESSURE (PSIG) -7 -1 4 10 16 21 27 SUCTION LINE TEMPERATURE (°F) SUCTION LINE TEMPERATURE (°C) 689 620 551 483 414 345 276 207 100 90 80 70 60 50 40 30 (036) 60HZ CHARGING CHART 20.0 30.0 40.0 50.0 60.0 70.0 80.0 OUTDOOR TEMP ° F ° C 115 46 125 52 45 7 55 13 65 18 75 24 95 35 105 41 85 29 50JS500090 For heating and cooling operation, the recommended airflow is 350 to 450 cfm for each 12,000 Btuh of rated cooling capacity. for units with optional electric heat, the airflow must not be reduced below the levels stated in Tables 2A and 2B. Airflow can be changed by changing the lead connection of the blower motor. Unit 50JS and JX three-speed motors (except sizes JS 018 and ...