York SUNLINE MagnaDRY DR180 Installation Manual

Also see for SUNLINE MagnaDRY DR 180: Submittal data sheet Installation manual

Contents

York SUNLINE MagnaDRY DR180 Installation Manual Manual pdf 54 page image

127915-YIM-A-040554 Unitary Products GroupINTERMITTENT BLOWERWith the room thermostat fan switch set to "AUTO" andthe system switch set to either the "AUTO" or "HEAT"settings, the blower is energized whenever a cooling orheating operation is requested. The blower is ener-gized after any specified delay associated with theoperation.When energized, the indoor blower has a minimum runtime of 30 seconds. Additionally, the indoor blower hasa delay of 10 seconds between operations.NO OUTDOOR AIR OPTIONSWhen the thermostat calls for the first stage of cooling,the low-voltage control circuit from "R" to "Y1" and "G"is completed. For first stage cooling, compressor #1,condenser fan motor #1, and condenser fan motor #2(if the ambient temperature is above 60°F), is ener-gized. After completing the specified fan on delay forcooling, the UCB will energize the blower motor.When the thermostat calls for the second stage of cool-ing, the low-voltage control circuit from "R" to "Y2" iscompleted. Compressor #2, condenser fan motor #3,and condenser fan motor #4 (if the ambient tempera-ture is above 60°F), is energized, provided it has notbeen locked-out.If there is an initial call for both stages of cooling, theUCB will delay energizing compressor #2 by 30 sec-onds in order to avoid a higher than normal current inrush.Once the thermostat has been satisfied, it will de-ener-gize Y1 and Y2. If the compressors have satisfied theirminimum run times, the compressors and condenserfans are de-energized. Otherwise, the unit operateseach cooling system until the minimum run times forthe compressors have been completed. Upon the finalcompressor de-energizing, the blower is stopped fol-lowing the elapse of the fan off delay for cooling.To be available, a compressor must not be locked-outdue to a high or low-pressure switch or freezestat tripand the anti-short cycle delay (ASCD) must haveelapsed.ECONOMIZER WITH SINGLE ENTHALPY SENSOR -When the room thermostat calls for "first-stage" cool-ing, the low voltage control circuit from "R" to "G" and"Y1" is completed. The UCB energizes the blowermotor (if the fan switch on the room thermostat is set inthe "AUTO" position) and drives the economizer damp-ers from fully closed to their minimum position. If theenthalpy of the outdoor air is below the setpoint of theenthalpy controller (previously determined), "Y1" ener-gizes the economizer. The dampers will modulate tomaintain a constant supply air temperature as moni-tored by the discharge air sensor. If the outdoor airenthalpy is above the setpoint, "Y1" energizes com-pressor #1, condenser fan motor #1, and condenserfan motor #2 (if the ambient temperature is above60°F).When the thermostat calls for "second-stage" cooling,the low voltage control circuit from "R" to "Y2" is com-pleted. The UCB energizes the first available compres-sor If the enthalpy of the outdoor air is below thesetpoint of the enthalpy controller (i.e. first stage hasenergized the economizer), "Y2" will energize com-pressor #1. If the outdoor air is above the setpoint, "Y2"will energize compressor #2.Once the thermostat has been satisfied, it will de-ener-gize Y1 and Y2. If the compressors have satisfied theirminimum run times, the compressors and condenserfans are de-energized. Otherwise, the unit operateseach cooling system until the minimum run times forthe compressors have been completed. Upon the finalcompressor de-energizing, the blower is stopped fol-lowing the elapse of the fan off delay for cooling, andthe economizer damper goes to the closed position. Ifthe unit is in continues fan operation the economizerdamper goes to the minimum position.ECONOMIZER WITH DUAL ENTHALPY SENSORS -The operation with the dual enthalpy sensors is identi-cal to the single sensor except that a second enthalpysensor is mounted in the return air. This return air sen-sor allows the economizer to choose between outdoorair and return air, whichever has the lowest enthalpyvalue, to provide maximum operating efficiency.ECONOMIZER (SINGLE OR DUAL) WITH POWEREXHAUST -This system operates as specified above with oneaddition. The power exhaust motor is energized 45seconds after the actuator position exceeds theexhaust fan setpoint on the economizer control. Whenthe power exhaust is operating, the second stage ofmechanical cooling will not operate. As always, the "R"to "G" connection provides minimum position but doesnot provide power exhaust operation.