York H5CE090 Technical Manual

Also see for H1CE150: User guide

Contents

York H5CE090 Technical Manual Manual pdf 6 page image

036-21083-007-A-04046 Unitary Products GroupSequence of OperationUNIT OPERATION - 7-1/2, 10 & 12-1/2 TONWhen the external control calls for cooling at terminal Y1:The system controller (SC) is energized. The system control-ler starts the compressors and enables the condenser fansby energizing contactor 1M (2M on the 10 and 12-1/2 ton,208/230 volt models).The single condenser fan is energized with the compressoron the 7-1/2 ton models.Condenser fan motor #1 is energized with the compressorson the 10 and 12-1/2 ton models while fan #2 is enabled withcompressor operation. Fan motor #2 operation is controlledthrough the Ambient Temperature Switch (ATS) which willde-energize the motor when the ambient temperature fallsbelow 70°FSafety Lockout: The system controller (SC) has a lockout cir-cuit to prevent compressor short-cycling on a safety controlwith automatic reset. If the high or low refrigerant pressureswitches (HP or LP) open, the SC will enter lockout mode.SC provides a 90 second bypass of the low pressure switchLP to prevent nuisance lockouts during unit start-up.A malfunction light (24V, 2 A max. resistive load) can beenergized through SC, by connecting the light between termi-nals X and B on TB1.NOTE: To reset the unit after a lockout:a. Turn the system switch on the thermostat to the “OFF”position and back to the ”COOL” position.ORb. Increase the set point of the room thermostat above thetemperature in the conditioned space and return it to itsoriginal setting. If the unit continues to be shut down byone of its safety controls, a service man should be calledto determine the cause of the problem. Repeated reset-ting of the lockout circuit may damage the unit.