Carrier AQUAZONE 50RHC Installation And Service Instructions Manual

Also see for AQUAZONE 50RHC: Operating and troubleshooting

Contents

Carrier AQUAZONE 50RHC Installation And Service Instructions Manual Manual pdf 34 page image

34Unit Start-Up Heating ModeNOTE: Operate the unit in heating cycle after checking thecooling cycle. Allow 5 minutes between tests for the pressureor reversing valve to equalize.1. Turn thermostat to lowest setting and set thermostatswitch to HEAT position.2. Slowly turn the thermostat to a higher temperature untilthe compressor activates.3. Check for warm air delivery at the unit grille within a fewminutes after the unit has begun to operate.4. Check the temperature of both supply and discharge wa-ter. Compare to Table 21. If temperature is within range,proceed. If temperature is outside the range, check theheating refrigerant pressures in Table 21.5. Once the unit has begun to run, check for warm air deliv-ery at the unit grille.6. Check air temperature rise across the coil when compres-sor is operating. Air temperature rise should be between20 and 30 F after 15 minutes at load.7. Check for vibration, noise and water leaks.Flow Regulation — Flow regulation can be accom-plished by two methods. Most water control valves have a flowadjustment built into the valve. By measuring the pressure dropthrough the unit heat exchanger, the flow rate can be deter-mined. See Tables 22-24. Adjust the water control valve untilthe flow of 1.5 to 2 gpm is achieved. Since the pressure con-stantly varies, two pressure gages may be needed in someapplications.An alternative method is to install a flow control device.These devices are typically an orifice of plastic material de-signed to allow a specified flow rate that are mounted on theoutlet of the water control valve. Occasionally these valvesproduce a velocity noise that can be reduced by applying someback pressure. To accomplish this, slightly close the leavingisolation valve of the well water setup.Flushing — Once the piping is complete, units require finalpurging and loop charging. A flush cart pump of at least 1.5 hpis needed to achieve adequate flow velocity in the loop to purgeair and dirt particles from the loop. Flush the loop in bothdirections with a high volume of water at a high velocity. Fol-low the steps below to properly flush the loop:1. Verify power is off.2. Fill loop with water from hose through flush cart beforeusing flush cart pump to ensure an even fill. Do not allowthe water level in the flush cart tank to drop below thepump inlet line to prevent air from filling the line.3. Maintain a fluid level in the tank above the return tee toavoid air entering back into the fluid.4. Shutting off the return valve that connects into the flushcart reservoir will allow 50 psi surges to help purge airpockets. This maintains the pump at 50 psi.5. To purge, keep the pump at 50 psi until maximum pump-ing pressure is reached.6. Open the return valve to send a pressure surge throughthe loop to purge any air pockets in the piping system.7. A noticeable drop in fluid level will be seen in the flushcart tank. This is the only indication of air in the loop.NOTE: If air is purged from the system while using a 10 in.PVC flush tank, the level drop will only be 1 to 2 in. sinceliquids are incompressible. If the level drops more than this,flushing should continue since air is still being compressed inthe loop. If level is less than 1 to 2 in., reverse the flow.8. Repeat this procedure until all air is purged.9. Restore power.Antifreeze may be added before, during or after the flushingprocess. However, depending on when it is added in theprocess, it can be wasted. Refer to the Antifreeze section formore detail.Loop static pressure will fluctuate with the seasons. Pres-sures will be higher in the winter months than during thewarmer months. This fluctuation is normal and should be con-sidered when charging the system initially. Run the unit ineither heating or cooling for several minutes to condition theloop to a homogenous temperature.When complete, perform a final flush and pressurize theloop to a static pressure of 40 to 50 psi for winter months or 15to 20 psi for summer months.After pressurization, be sure to remove the plug from theend of the loop pump motor(s) to allow trapped air to bedischarged and to ensure the motor housing has been flooded.Be sure the loop flow center provides adequate flow throughthe unit by checking pressure drop across the heat exchanger.Compare the results to the data in Tables 22-24.Table 21 — Typical Unit Operating Pressures and TemperaturesLEGENDTo avoid possible injury or death due to electrical shock,open the power supply disconnect switch and secure it inan open position before flushing system.ENTERINGWATERTEMP (F)(EWT)GPM/TONCOOLING HEATINGSuctionPressure(psig)DischargePressure(psig)Super-heat(F)Sub-cooling(F)WaterTempRise(F)AirTempDrop (F)DBSuctionPressure(psig)DischargePressure(psig)Super-heat (F)Sub-cooling(F)WaterTempDrop (F)DBAirTempRise (F)301.5 75-85 90-105 25-40 12-20 21-24 21-26 34- 39 167-186 12-16 1-4 7.6- 8.4 14-202.3 74-84 80- 95 25-40 11-18 13-16 21-26 37- 43 172-191 12-16 1-4 4.8- 5.6 16-223.0 73-83 70- 85 25-40 10-16 6-11 21-26 40- 46 177-196 12-16 1-4 3.4- 4.2 16-22501.5 75-85 125-155 12-20 10-18 20-23 20-25 50- 60 180-210 10-17 1-5 10.8-11.9 23-292.3 74-84 120-142 12-20 9-16 12-15 20-25 53- 62 185-215 10-17 1-5 6.7- 8.1 24-303.0 73-83 115-138 12-20 8-14 8-12 20-25 55- 65 190-220 10-17 1-5 5.1- 5.9 25-31701.5 75-85 179-198 9-16 8-15 19-22 19-24 71- 82 205-230 14-19 1-5 14.0-15.2 28-342.3 74-84 168-186 9-16 8-14 12-17 19-24 73- 85 210-238 14-19 1-5 9.0-10.2 30-373.0 73-83 158-175 9-16 8-12 7-12 19-24 76- 88 215-242 14-19 1-5 6.7- 7.9 31-38901.5 75-85 229-251 9-17 8-15 18-21 17-23 85- 95 220-260 18-28 2-5 14.4-16.6 32-392.3 74-84 218-241 9-17 8-14 10-14 17-23 90-100 225-265 18-28 2-5 10.8-12.4 33-413.0 73-83 208-230 9-17 8-12 6-11 17-23 95-105 230-270 18-28 2-5 7.2- 8.3 35-421101.5 77-87 280-320 8-15 10-25 17-20 15-202.3 76-86 270-310 8-15 10-24 9-13 15-203.0 75-85 260-300 8-15 10-22 5-10 15-20DB — Dry BulbEAT — Entering Air TemperatureNOTES:1. Based on nominal 400 cfm per ton airflow, 70 F EAT heating and 80/67 FEAT cooling.2. Cooling air and water numbers can vary greatly with changes in humidity.3. Subcooling is based upon the head pressure at compressor service port.4. Unit should not be operated in heating mode with an EWT of 110.