Carrier AQUAZONE 50KQE Series Installation, Operation And Maintenance Instructions

Contents

Carrier AQUAZONE 50KQE Series Installation, Operation And Maintenance Instructions Manual pdf 22 page image

226 - START-UPUse the procedure outlined below to initiate proper unit start-up.NOTE: This equipment is designed for indoor installation only.WARNING: When the disconnect switch is closed, highvoltage is present in some areas of the electrical panel. Exercisecaution when working with the energised equipment.1. Adjust all valves to the full open position and turn on theline power to all heat pump units.2. Operate each unit in the cooling mode first. Room tempe-rature should be in the normal range (i.e., approximately10 to 27∞C dry bulb). Loop water temperature entering theheat pumps should be at least 4∞C but not in excess of43∞C. Refer to Table 4 for more specific information onthe operating parameters of units.NOTE: Three factors determine the operating limits of a unit:(1) return-air temperature, (2) water temperature and (3)ambient temperature. Whenever any one of these factors is ata minimum or maximum level, the other two factors must beat normal levels to ensure proper unit operation. Flow ratesmust be at nominal levels.6.1 - Unit start-up/cooling1. Turn the unit thermostat to the cooling position and turnthe fan speed switch to “HI.” If the unit has an optionalMCO thermostat, set the selector switch to cool. Both thefan and compressor should run.2. Check for cool air delivery at unit grille 15 minutes afterthe unit has begun operating. List the identificationnumber of any machines that do not function at this time.3. Check the elevation and cleanliness of the condensate lines;any dripping could be a sign of a blocked line.4. Select low fan speed. Air flow should decrease and com-pressor should operate.5. Slowly turn thermostat toward warmer position. Both fanand compressor should shut off when thermostat set pointequals room temperature. Room temperature must bebelow 32∞C for unit to shut off.6. Operate each heat pump in the heating cycle immediately afterchecking cooling cycle operation. A time delay will preventthe compressor from re-starting for approximately 5 minutes.6.2 - Operating limitsEnvironment - This equipment is designed for indoor installa-tion ONLY.Power supply - A voltage variation of ± 10% of nameplateutilisation voltage is acceptable.50KQE starting conditions - The 50KQE units will start andoperate at an ambient temperature of 10∞C with entering airtemperature at 10∞C, entering water at 16∞C, and with both airand water at nominal flow rates.NOTE: These operating limits are not normal or continuousoperating conditions. It is assumed that such a start-up is forthe purpose of bringing the building space up to occupancytemperature.6.3 - Unit start-up/heating1. Adjust the unit thermostat to the warmest setting and turnthe fan speed switch to “HI.” If the unit has an optionalMCO thermostat, set the selector switch to heat. Theblower should start immediately and after the time delay iscomplete, the compressor will start.2. Once the unit has begun to run, check for warm air deliveryat the unit grille. Again, the installing contractor must listthe serial number of any machine that does not function.3. Log the unit operating conditions at initial start-up foreach unit to establish a permanent operating record.4. Select low fan speed. Airflow should decrease and com-pressor should continue to operate.5. Slowly turn thermostat toward cooler position. Both fanand compressor should shut off when thermostat set pointequals room temperature. Room temperature must beabove 19∞C for unit to shut off.6.4 - Flow regulationFlow regulation can be accomplished by two methods. Mostwater control valves have a flow adjustment built into the valve.By measuring the pressure drop through the unit heat exchanger,the flow rate can be determined (see Table 8). Adjust the watercontrol valve until the flow of 0.027 to 0.036 l/s per kW cooling isachieved. Since the pressure constantly varies, two pressuregauges may be needed in some applications.An alternative method is to install a flow control device. Thesedevices are typically an orifice of plastic material designed toallow a specified flow rate that are mounted on the outlet of thewater control valve. Occasionally these valves produce a velocitynoise that can be reduced by applying some back pressure. Toaccomplish this, slightly close the leaving isolation valve of thewell water set-up.CAUTION: DO NOT use “Stop Leak” or any similar chemicalagent in this system. Addition of these chemicals to the loopwater will foul the system and inhibit unit operation.Table 8 - Coaxial water pressure drop50KQE Flow Pressure drop, kPal/s 0∞C 10∞C 20∞C 30∞C007 0.063 12.1 7.8 6.5 5.70.088 16.8 12.6 11.5 10.50.114 23.2 18.5 17.9 16.4009 0.069 4.5 3.3 2.7 2.70.101 6.1 5.4 5.1 4.80.133 9.7 8.4 7.4 6.8012 0.076 5.1 3.9 3.3 3.00.107 7.2 5.7 5.7 5.40.145 11.5 10.2 9.1 8.4015 0.101 10.8 7.8 7.8 6.90.145 16.1 12.9 12.9 12.60.196 26.8 23.0 34.2 20.8019 0.107 11.1 8.7 8.0 7.80.158 17.9 15.5 15.0 14.10.208 34.4 27.5 25.1 24.0