Carrier AQUAZONE 50HQL072-120 Installation, Start-up And Service Instructions Manual

Carrier AQUAZONE 50HQL072-120 Installation, Start-up And Service Instructions Manual Manual pdf 31 page image

31heat/cool mode, Y1 is used for cooling stage 1, Y2 is used forcooling stage 2, W1 is used for heating stage 1 and O/W2 isused for heating stage 2. Select ON for heat pump applications.In heat pump mode, Y1 used is for compressor stage 1, Y2 isused for compressor stage 2, W1 is used for heating stage 3 oremergency heat, and O/W2 is used for RV (heating or cooling)depending upon switch 4 setting.O/B Thermostat Type — Switch 4 provides selection for heatpump O/B thermostats. O is cooling output. B is heating out-put. Select ON for heat pumps with O output. Select OFF forheat pumps with B output.Dehumidification Fan Mode — Switch 5 provides selectionof normal or dehumidification fan mode. Select OFF for dehu-midification mode. The fan speed relay will remain OFF dur-ing cooling stage 2. Select ON for normal mode. The fan speedrelay will turn on during cooling stage 2 in normal mode.Switch 6 — Not used.Boilerless Operation — Switch 7 provides selection of boiler-less operation and works in conjunction with switch 8. Inboilerless operation mode, only the compressor is used forheating when FP1 is above the boilerless changeover tempera-ture set by switch 8 below. Select ON for normal operation orselect OFF for boilerless operation.Boilerless Changeover Temperature — Switch 8 on S1 pro-vides selection of boilerless changeover temperature set point.Select OFF for set point of 50 F or select ON for set pointof 40 F.If switch 8 is set for 50 F, then the compressor will be usedfor heating as long as the FP1 is above 50 F. The compressorwill not be used for heating when the FP1 is below 50 F and thecompressor will operate in emergency heat mode, staging onEH1 and EH2 to provide heat. If a thermal switch is being usedinstead of the FP1 thermistor, only the compressor will be usedfor heating mode when the FP1 terminals are closed. If the FP1terminals are open, the compressor is not used and the controlgoes into emergency heat mode.DIP SWITCH BLOCK 2 (S2) — This set of DIP switches isused to configure accessory relay options. See Fig. 8B, 9B and10B.Switches 1 to 3 — These DIP switches provide selection ofAccessory 1 relay options. See Table 17 for DIP switchcombinations.Switches 4 to 6 — These DIP switches provide selectionof Accessory 2 relay options. See Table 18 for DIP switchcombinations.Auto Dehumidification Mode or High Fan Mode — Switch 7provides selection of auto dehumidification fan mode or highfan mode. In auto dehumidification fan mode the fan speedrelay will remain off during cooling stage 2 if terminal H isactive. In high fan mode, the fan enable and fan speed relayswill turn on when terminal H is active. Set the switch to ON forauto dehumidification fan mode or to OFF for high fan mode.Switch 8 — Not used.Table 17 — DIP Switch Block S2 —Accessory 1 Relay OptionsLEGENDNOTE: All other DIP switch combinations are invalid.Table 18 — DIP Switch Block S2 —Accessory 2 Relay OptionsLEGENDNOTE: All other switch combinations are invalid.Units with Modulating Hot Water Reheat(HWR) Option — A heat pump equipped with Hot WaterReheat (HWR) can operate in three modes: cooling, coolingwith reheat, and heating. The cooling/heating modes are likeany other Aquazone™ water source heat pump. The reversingvalve ("O" signal) is energized in cooling, along with the com-pressor contactor(s) and blower relay. In the heating mode, thereversing valve is deenergized. Almost any thermostat willactivate the heat pump in heating or cooling modes. TheDeluxe D microprocessor board, which is standard with theHWR option, will accept either heat pump (Y,O) thermostatsor non-heat pump (Y,W) thermostats.The reheat mode requires either a separate humidistat/dehumidistat or a thermostat that has an integrated dehumidifi-cation function for activation. The Deluxe D board is config-ured to work with either a humidistat or dehumidistat input toterminal “H” (DIP switch settings for the Deluxe D board areshown in Table 19). Upon receiving an “H” input, the DeluxeD board will activate the cooling mode and engage reheat.Table 19 — Humidistat/Dehumidistat Logic andDeluxe D DIP Switch SettingsTable 20 shows the relationship between thermostat inputsignals and unit operation. There are four operational inputs forsingle-stage units and six operational inputs for dual-stageunits:• Fan Only• Cooling Stage 1• Cooling Stage 2• Heating Stage 1• Heating Stage 2• Reheat ModeHWR APPLICATION CONSIDERATIONS — Unlikemost hot gas reheat options, the HWR option will operate overa wide range of entering-water temperatures (EWTs). Specialflow regulation (water regulating valve) is not required for lowEWT conditions. However, below 55 F, supply-air tempera-tures cannot be maintained at 72 F because the cooling capacityexceeds the reheat coil capacity at low water temperatures. Be-low 55 F, essentially all water is diverted to the reheat coil (noheat of rejection to the building loop). Although the HWR op-tion will work fine with low EWTs, overcooling of the spacemay result with well water systems or, on rare occasions, withground loop (geothermal) systems (NOTE: Extended rangeunits are required for well water and ground loop systems).Since dehumidification is generally only required in cooling,most ground loop systems will not experience overcooling ofthe supply-air temperature. If overcooling of the space is a con-cern (e.g., computer room well water application), auxiliaryheating may be required to maintain space temperature whenACCESSORY 1RELAY OPTIONSDIP SWITCH POSITION1 2 3Cycle with Fan On On OnDigital NSB Off On OnWater Valve — Slow Opening On Off OnOAD On On OffNSB — Night SetbackOAD — Outside Air DamperACCESSORY 2RELAY OPTIONSDIP SWITCH POSITION4 5 6Cycle with Fan On On OnDigital NSB Off On OnWater Valve — Slow Opening On Off OnOAD On On OffNSB — Night SetbackOAD — Outside Air DamperSensor 2.1 2.2 2.3 Logic Reheat(ON) - HReheat(OFF) - HHumidistat Off Off Off Reverse 0 VAC 24 VACDehumidistat Off On Off Standard 24 VAC 0 VAC