Carrier Aquazone 50PCH Installation, Start-up And Service Instructions Manual

Contents

22HOT GAS REHEAT CONTROL — Units with hot gas re-heat (HGRH) will include an additional H terminal on the im-put terminal board for dehumidification control. To enable acall for dehumidification, a 24V signal must be sent to the Hterminal with no voltage applied to the Y1 or O terminals. Anycall for cooling (Y1 and O) will override the dehumidificationcall.Unit heat pumps are supplied with a 50 VA control trans-former as standard. Models with WSHP Open, Deluxe D con-trol package, hot gas reheat (HGRH), or waterside economizeroptions are supplied with a 75VA transformer. The VA ca-pacity of the transformer should be considered when connect-ing low voltage accessories to the heat pump such as thermo-stats or solenoid valves. Table shows the VA draw of factory-mounted components in the low voltage heat pump. The totalVA draw of the heat pump internal components plus any at-tached accessories must be lower than the VA capacity of theunit control transformer.Step 9 — Wire Field ControlsSAFETY DEVICES AND UNIT PROTECTION MOD-ULE (UPM) — Each unit is factory provided with a UPMboard that controls the compressor operation and monitors thesafety. See Fig. 20.If the unit is being connected to a thermostat with a mal-function light, this connection is made at the unit malfunctionoutput or relay. See Table 9 for UPM board fault blink codes.Fig. 20 — Unit Protection Module (UPM)Table 8 — Low Voltage VA DrawIMPORTANT: Exceptionally long runs of thermostat wireshould be avoided to prevent voltage drops in the controlcircuit.CAUTIONExceeding the transformer capacity can result in low con-trol voltage, erratic unit operation or damage to the heatpump.WARNINGTo avoid possible injury or death due to electrical shock,open the power supply disconnect switch and secure it inan open position during installation.123456 7 9 101112131714151681 Board Power Indicator2 UPM Status LED Indicator3 Water Coil Freeze Protection Temperature Selection [R30]4 Air Coil Freeze Protection Temperature Selection5 UPM Settings6 Water Coil Freeze Connection7 Air Coil Freeze Connection8 LED Status-Diagnostic Connection9 24VAC Power Input10 Compressor Contact Output11 High Pressure Switch Connection12 Call for Compressor Y113 Low Pressure Switch Connection14 24VAC Power Common15 Condensate Overflow Sensor16 Dry Contact17 UPM Ground StandoffSTANDARD CONSTRUCTION HOT GAS REHEAT OR ECONOMIZER OPTIONAL COMPONENTSComponent VA Component VA Component VABlower Relay (PSCmotors only) 6-7 Total from ‘Standard’ 22-26 Monitor Relay (VA drawper relay) 6-7Reversing ValveSolenoid 8-9 Additional ControlRelays 12-14 Internal 2 WayMotorized Valve 7Compressor Contactor 6-8 Hot Gas ReheatSolenoid 8-9Complete C board 2 — —Total VA draw 22-26 Total VA draw 42-49