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All internal unit resistances have been deducted from the total static pressure of the blower. The Factory Setting 5 Unitary Products 17 035-17233-000-C-0702 TABLE 13: STATIC RESISTANCES1 RESISTANCE, IWG CFM 15 TON 20 TON 4500 5765 7200 6000 7000 9400 WET COIL 0.1 0.1 0.1 0.1 0.1 0.1 ECONOMIZER OPTION 0.1 0.1 0.1 0.1 0.1 0.1 HORIZONTAL DUCT CONN.2 0.2 0.3 0.5 0.2 0.3 0.5 1 Deduct these resistance values from the available unit ESP values listed in the respective blower performance table except for Horizontal Duct Connections. 2 Add these values due to less airflow resistance. TABLE 14: POWER EXHAUST PERFORMANCE STATIC RESISTANCE OF RETURN DUCTWORK, IWG SPEED1 0.2 0.3 0.4 0.5 0.6 CFM kW CFM kW CFM kW CFM kW CFM kW HIGH2 5250 0.83 4500 0.85 4200 0.88 3750 0.93 3000 0.99 MEDIUM 4900 0.77 3900 0.79 3500 0.82 2900 0.85 - - LOW 4400 0.72 3700 0.74 3000 0.78 - - - - 1 Power exhaust motor is a 3/4 HP, PSC type with sleeve bearings, a 48 frame and inherent protection. 2 The factory setting. TABLE 15: BLOWER MOTOR AND DRIVE DATA MODEL SIZE DRIVE BLWR RANGE (RPM) MOTOR1 ADJ. MOTOR PULLEY FIXED BLOWER PULLEY BELT (NOTCHED) HP FRAME EFF. (%) DESIGN- NATION O/D (in.) PITCH DIA (in.) BORE (in.) DESIGN- NATION O/D (in.) PITCH DIA (in.) BORE (in.) DESIG- NATION PITCH LNGTH. (in.) QTY 15 Ton Std. 850/1065 5 184T 89.5 1VP56 5.35 4.3- 5.32 1-1/8 BK90 8.75 8.4 1 BX70 71.8 1 High Spd. Acs. 965/1190 BK80 7.75 7.4 1 BX68 69.8 1 20 Ton Std. 870/1025 7.5 213T 91 1VP68 6.75 5.5- 6.52 1-3/8 BK120 11.75 11.4 1-3/16 BX83 84.8 1 High Spd. Acs. 950/1120 BK110 10.75 10.4 1-3/16 BX80 81.8 1 1 All motors have a nominal speed of 1800 RPM, a 1.15 service factor and a solid base. They can operate to the limit of their service factor because they are located in the moving air, upstream of any heating device. 2 DO NOT close this pulley below 1 turn. 18 Unitary Products 035-17233-000-C-0702 OPERATION COOLING SYSTEM The cooling section is a complete factory package utilizing an air-cooled condenser. The system is factory-charged with Refrigerant-22. The compressors are hermetically sealed, internally sprung and base-mounted with rubber-insulated hold-down bolts. Compressors have inherent (internal) protection. If there is an abnormal temperature rise in a compressor, the protector will open to shut down the compressor. PRELIMINARY OPERATION COOLING After installation has been completed, energize the crankcase heaters for at least four hours before operating the unit. After the initial installation, the compressors should be given three false starts (energized just long enough to make a few revolutions) with 5-7 minutes delay between each start, before being put into full time service. NOTE: Prior to each cooling season, the crankcase heaters must be energized at least 8 hours before system is put into operation. COOLING SEQUENCE OF OPERATION NO OUTDOOR AIR OPTIONS When the room thermostat calls for first-stage cooling, the low voltage control circuit from R to G and Y1 is completed to energize compressor #1, condenser fan motor #1, condenser fan motor #2 (if the ambient temperature is above 60F), and the supply air blower motor (if the fan switch on the room thermostat is set in the AUTO position). When the thermostat calls for second-stage cooling, the low voltage control circuit from R to Y2 is completed to energize compressor #2. After the thermostat is satisfied and opens, all components will stop simultaneously. The blower motor will continue to operate if the fan switch on the room thermostat is set in the ON position. ECONOMIZER WITH SINGLE ENTHALPY SENSOR When the room thermostat calls for first-stage cooling, the low voltage control circuit from R to G and Y1 is completed. The R to G circuit energizes the blower motor (if the fan switch on the room thermostat is set in the AUTO position) and drives the economizer dampers from fully closed to their minimum position. If the enthalpy of the outdoor air is below the setpoint of the enthalpy controller (previously determined), Y1 energizes the economizer. The dampers will modulate to maintain a constant supply air temperature as monitored by the discharge air sensor. If the outdoor air enthalpy is above the setpoint, Y1 energizes compressor #1, condenser fan motor #1, and condenser fan motor #2 (if the ambient temperature is above 60°F). When the thermostat calls for second-stage cooling, the low voltage control circuit from R to Y2 is completed. If the enthalpy of the outdoor air is below the setpoint of the enthalpy controller (i.e. first stage has energized the economizer), Y2 will energize compressor #1. If the outdoor air is above the setpoint, Y2 will energize compressor #2. After the thermostat is satisfied and opens, all components will stop simultaneously. The blower motor will continue to operate if the fan switch on the room thermostat is set in the ON position. ECONOMIZER WITH DUAL ENTHAL...

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