Carrier AQUAZONE 50PCH Installation And Service Instructions Manual

Also see for AQUAZONE 50PCH: Installation, Start-Up and Service Instructions Installation and service instructions Installation, Start-Up and Service Instructions

36• The IAQ sensor reading is greater than the DCV startcontrol set point.The control has four user adjustable set points: DCV startcontrol set point, DCV maximum control set point, minimumdamper position, and DCV maximum damper position.Two-Position OA Damper — The control can be configuredto operate a ventilation damper in a two-position ventilationmode to provide the minimum ventilation requirements duringoccupied periods.WATERSIDE ECONOMIZER — The WSHP Open control-ler has the capability of providing modulating or two-positionwater economizer operation (for a field-installed economizercoil mounted to the entering air side of the unit and connectedto the condenser water loop) in order to provide free cooling(or preheating) when water conditions are optimal. Water econ-omizer settings can be accessed through the equipment statusscreen. The following conditions must be true for economizeroperation:• SAT reading is available.• LWT reading is available.• If occupied, the SPT is greater than the occupied coolingset point or less than the occupied heating set point andthe condenser water is suitable.• Space temperature reading is valid.• If unoccupied, the SPT is greater than the unoccupiedcooling set point or less than the unoccupied heating setpoint and the condenser water is suitable.Modulating Water Economizer Control — The control hasthe capability to modulate a water valve to control condenserwater flowing through a coil on the entering air side of the unit.Cooling — The purpose is to provide an economizer coolingfunction by using the water loop when the entering water looptemperature is suitable (at least 5° F below space temperature).If the water loop conditions are suitable, then the valve willmodulate open as required to maintain a supply-air temperaturethat meets the load conditions. Should the economizer coil ca-pacity alone be insufficient for a period greater than 5 minutes,or should a high humidity condition occur, then the compressorwill also be started to satisfy the load. Should the SAT ap-proach the minimum cooling SAT limit, the economizer valvewill modulate closed during compressor operation.Heating — Additionally, the control will modulate the watervalve should the entering water loop temperature be suitablefor heating (at least 5° F above space temperature) and heat isrequired. The valve will be controlled in a similar manner ex-cept to satisfy the heating requirement. Should the economizercoil capacity alone be insufficient to satisfy the space load con-ditions for more than 5 minutes, then the compressor will bestarted to satisfy the load. Should the SAT approach the maxi-mum heating SAT limit, the economizer valve will modulateclosed during compressor operation.Two-Position Water Economizer Control — The control hasthe capability to control a NO or NC, two-position water valveto control condenser water flow through a coil on the enteringair side of the unit.Cooling — The purpose is to provide a cooling economizerfunction directly from the condenser water loop when the en-tering water loop temperature is suitable (at least 5° F belowspace temperature). If the optional coil is provided and the wa-ter loop conditions are suitable, then the valve will open to pro-vide cooling to the space when required. Should the capacitybe insufficient for a period greater than 5 minutes, or should ahigh humidity condition occur, then the compressor will bestarted to satisfy the load. Should the SAT reach the minimumcooling SAT limit, the economizer valve will close duringcompressor operation.Heating — Additionally, the economizer control will open thewater valve should the entering water loop temperature be suit-able for heating (at least 5° F above space temperature) andheat is required. The valve will be controlled in a similar man-ner except to satisfy the heating requirement. Should the coilcapacity be insufficient to satisfy the space load for more than5 minutes, then the compressor will be started to satisfy theload. Should the SAT reach the maximum heating SAT limit,the economizer valve will close during compressor operation.DEMAND LIMIT — The WSHP Open controller has theability to accept three levels of demand limit from the network.In response to a demand limit, the unit will decrease its heatingset point and increase its cooling set point to widen the range inorder to immediately lower the electrical demand. The amountof temperature adjustment in response is user adjustable forboth heating and cooling and for each demand level. The re-sponse to a particular demand level may also be set to zero.CONDENSER WATER LINKAGE — The control pro-vides optimized water loop operation using an universal con-troller (UC) open loop controller. Loop pump operation is auto-matically controlled by WSHP equipment occupancy sched-ules, unoccupied demand and tenant override conditions.Positive pump status feedback prevents nuisance fault trips.The condenser water linkage operates when a request for con-denser water pump operation is sent from each WSHP to theloop controller. This request is generated whenever any WSHPis scheduled to be occupied, is starting during optimal start (forwarm-up or pull down prior to occupancy), there is an unoccu-pied heating or cooling demand, or a tenant pushbutton over-ride. At each WSHP, the water loop temperature and the looppump status is given. The WSHP will NOT start a compressoruntil the loop pumps are running or will shutdown the com-pressors should the pumps stop. This prevents the WSHP fromoperating without water flow and thus tripping out on refriger-ant pressure, causing a lockout condition. The WSHP Opencontroller control will prevent this from occurring. Also, theloop controller can be configured to start the pumps only after aconfigurable number of WSHPs are requesting operation (from1-"N"). This can be used to prevent starting the entire loop op-eration for only one WSHP. Meanwhile, the WSHPs will notoperate if the loop pump status is off and therefore the WSHPcompressor will not run.COMPLETE C AND DELUXE D BOARDSYSTEM TESTSystem testing provides the ability to check the controloperation. The control enters a 20-minute Test mode bymomentarily shorting the test pins. All time delays are in-creased 15 times. See Fig. 13-17.Test Mode — To enter Test mode on Complete C or DeluxeD controls, cycle the fan 3 times within 60 seconds. The LED(light-emitting diode) will flash a code representing the last faultwhen entering the Test mode. The alarm relay will also power onand off during Test mode. See Tables 29-31. To exit Test mode,short the terminals for 3 seconds or cycle the fan 3 times within60 seconds.NOTE: Deluxe D control has a flashing code and alarm relaycycling code that will both have the same numerical label.For example, flashing code 1 will have an alarm relay cyclingcode 1. Code 1 indicates the control has not faulted since thelast power off to power on sequence.WSHP Open Test Mode — To enter WSHP Open testmode, navigate from the BACview6 home screen to the config-uration screen. Choose the service screen and enable unit test.The controller will then test the following:FAN TEST — Tests all fan speeds, sequences fan from low tohigh, and operates each speed for one minute. Resets to disableon completion.COMPRESSOR TEST — Tests compressor cooling andheating operation. Sequences cooling stage 1 then cooling