Carrier AQUAZONE 50PSH Installation And Service Instructions Manual

46screen. 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 universalcontroller (UC) open loop controller. Loop pump operation isautomatically controlled by WSHP equipment occupancyschedules, 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 anunoccupied heating or cooling demand, or a tenant pushbuttonoverride. At each WSHP, the water loop temperature and theloop pump status is given. The WSHP will NOT start a com-pressor until the loop pumps are running or will shutdown thecompressors should the pumps stop. This prevents the WSHPfrom operating without water flow and thus tripping out on re-frigerant pressure, causing a lockout condition. The WSHPOpen controller control will prevent this from occurring. Also,the loop controller can be configured to start the pumps onlyafter a configurable number of WSHPs are requesting opera-tion (from 1-"N"). This can be used to prevent starting the en-tire loop operation for only one WSHP. Meanwhile, theWSHPs will not operate if the loop pump status is off andtherefore the WSHP compressor will not run.COMPLETE C AND DELUXE D BOARDSYSTEM TESTTest mode provides the ability to check the control opera-tion in a timely manner. The control enters a 20-minute testmode by momentarily shorting the test terminals. All time de-lays are sped up 15 times. The follow operations are commonto both Complete C and Deluxe D controls.Test Mode — To enter Test mode, cycle the power 3 timeswithin 60 seconds. The LED will flash a code representing thelast fault when entering the Test mode. The alarm relay willalso power on and off during Test mode. See Tables 34 and 35.To exit Test mode, short the terminals for 3 seconds or cyclethe power 3 times within 60 seconds.NOTE: The flashing code and alarm relay cycling code willboth have the same numerical label. For example, flashingcode 1 will have an alarm relay cycling code 1. Code 1 indi-cates the control has not faulted since the last power off topower on sequence.Table 34 — Complete C Control Current LEDStatus and Alarm Relay OperationsLEGENDNOTES:1. Slow flash is 1 flash every 2 seconds.2. Fast flash is 2 flashes every 1 second.3. EXAMPLE: “Flashing Code 2” is represented by 2 fast flashes followed by a10-second pause. This sequence will repeat continually until the fault is cleared.°°°°LED STATUS DESCRIPTION OF OPERATION ALARM RELAYOnNormal Mode OpenNormal Mode with PM Warning Cycle (closed 5 sec.,open 25 sec.)Off Complete C Control is non-functional OpenSlow Flash Fault Retry OpenFast Flash Lockout ClosedSlow Flash Over/Under Voltage Shutdown Open, (Closed after15 minutes)Flashing Code 1 Test Mode — No fault in memory Cycling Code 1Flashing Code 2 Test Mode — HP Fault in memory Cycling Code 2Flashing Code 3 Test Mode — LP Fault in memory Cycling Code 3Flashing Code 4 Test Mode — FP1 Fault in memory Cycling Code 4Flashing Code 5 Test Mode — FP2 Fault in memory Cycling Code 5Flashing Code 6 Test Mode — CO Fault in memory Cycling Code 6Flashing Code 7 Test Mode — Over/Undershutdown in memory Cycling Code 7Flashing Code 8 Test Mode — PM in memory Cycling Code 8Flashing Code 9 Test Mode — FP1/FP2Swapped Fault in memory Cycling Code 9CO — Condensate Overflow LED — Light-Emitting DiodeFP — Freeze Protection LP — Low PressureHP — High Pressure PM — Performance Monitor