York ZB Series Installation Manual

5808009-YIM-A-0320Johnson Controls Ducted Systems 69Smart Equipment™ UCB - limit, 24 VAC power, and shutdown connectionsLocation Label Description Function and commentsBLIMIT Monitored 24 VAC input through heat sectionlimit switch(es)If voltage is absent, indicating the heat section is over-temperature, the UCB willbring on the indoor blowerC 24 VAC, 75 VA transformer Commonreferenced to cabinet groundConnects through circuit traces to thermostat connection strip C and indoorblower VFD pin C24V 24 VAC, 75 VA transformer hot Powers the UCB microprocessor, connects through circuit trace to the SD 24terminalSD 2424 VAC hot out for factory accessory smokedetector, condensate overflow and/or usershutdown relay switching in seriesConnects through circuit trace to thermostat connection strip SD-24. A wiringharness jumper plug connecting SD 24 to SD R is in place if factory accessoriesfor unit shutdown are not used - this jumper plug must be removed if theswitching of field-added external accessories for unit shutdown are wiredbetween thermostat connection strip SD-24 and RSD R24 VAC hot return from factory accessorysmoke detector, condensate overflow anduser shutdown relay switching in seriesConnects through circuit trace to the R terminal on the upper left of the boardR 24 VAC hot for switched inputs to the UCBConnects through circuit trace to the thermostat connection strip R terminal,right FAN OVR pin, right HPS1 pin, right HPS2 pin, lower DFS pin and lowerAPS pinSmart Equipment™ UCB - space temperature sensor connectionsLocation Label Description Function and commentsCSTSpace Temperature sensor input from 10KΩ @77°F, Type III negative temperature coefficientthermistorPositive of VDC circuit (3.625 VDC reading to COM with open circuit),effective if “Thermo- stat-only Control” parameter is set OFF, spacesensor override momentary shorts ST to COM to initiate/terminatetemporary occupancyCOM Common for ST and SSO inputs Negative of VDC circuit for ST and SSO inputsSSO Space Sensor Offset input from 0 to 20KΩpotentiometerPositive of VDC circuit (3.625 VDC reading to COM with open circuit),10KΩ/2.5 VDC is 0°F offset, 0Ω/0 VDC is maximum above offset and20KΩ/3.4 VDC is maximum below offset from active space temperaturesetpointSmart Equipment™ UCB - temperature sensor connectionsLocation Label Description Function and commentsDSAT+Supply Air Temperature sensor input from 10KΩ@ 77°F, Type III negative temperature coefficientthermistorInput required for operation; 3.625 VDC reading SAT+ to SAT– with opencircuit. Used in heat/cool staging cutouts, free cooling operation, demandventilation operation, comfort ventilation operation, economizer loadingoperation, VAV cooling operation, hydronic heat operation.RAT+Return Air Temperature sensor input from 10KΩ@ 77°F, Type III negative temperature coefficientthermistorInput required for operation; 3.625 VDC reading RAT+ to RAT– with opencircuit. Used in return air enthalpy calculation. Substitutes for spacetemperature if no other space temperature input is present.OAT+Outside Air Temperature sensor input from 10KΩ@ 77°F, Type III negative temperature coefficientthermistorInput required for operation but may be a communicated value; 3.625 VDCreading OAT+ to OAT– with open circuit. Used in heat/cool cutouts, lowambient cooling determination, dry bulb free cooling changeover, outsideair enthalpy calculation, economizer loading operation, heat pump demanddefrost calculation.CC1+#1 refrigerant circuit Condenser Coil temperaturesensor input from 10KΩ @ 77°F, Type III negativetemperature coefficient thermistorInput required for heat pump units, not required for A/C units; 3.625 VDCreading CC1+ to CC1– with open circuit. Used in heat pump demanddefrost calculation.EC1+#1 refrigerant circuit Evaporator Coil temperaturesensor input from 10KΩ @ 77°F, Type III negativetemperature coefficient thermistorInput required for operation; 3.625 VDC reading EC1+ to EC1– with opencircuit. Used in suction line temperature safety.