Problem Possible Cause Solution | Sterling SCW Series guide

	Problem	Possible Cause	Solution
			Allow time to cool and reset.
			Check for high/low voltage.
			Voltage must be within plus
		Compressor internal overload	or minus ten percent (±10%)
		Compressor internal overload	of nameplate rating.
		open.	of nameplate rating.
		open.	Check for poor compressor
			Check for poor compressor
			electrical connections.
			Check compressor rotation
			on scroll compressors.
		Compressor contactor	Repair or replace.
		holding coil open.	Repair or replace.
	Pump runs,	holding coil open.
	Pump runs,	Defective fan motor.	Repair or replace.
	compressor does not	Fan motor out on overload.	Reset and test.
	(cont’d).	Defective freezestat.	Replace.
		Refrigerant low.	Check the refrigerant charge.
		Defective fan cycling control.	Replace.
		Low refrigerant pressure	Sight glass should be clear
		Low refrigerant pressure	while comperssor runs. Call
		switch contact open.	for service if bubbling or
			foaming.
		Defective pump motor	Repair or replace.
		interlock to compressor	Repair or replace.
		control circuit.
		Broken wire in the	Locate and repair.
		compressor control circuit.	Locate and repair.
		compressor control circuit.
		Freezestat control setting is	Lower set point to 10°F (6ºC)
		Freezestat control setting is	below the leaving water
	Pump runs, compressor	too high.	temperature you want with at
	Pump runs, compressor		least 15 degrees differential.
	cycles at short intervals.		Check refrigeration charge;
		Refrigerant is too low.	check refrigerant sight glass
		Refrigerant is too low.	for bubbles or a level in the
			for bubbles or a level in the
			glass.
		Improper water/glycol	Be sure the antifreeze
		Improper water/glycol	mixture protection is right for
	Leaving water temperature is	mixture.	mixture protection is right for
		mixture.	the process.
			the process.
	not at set point.	Defective freezestat control.	Replace.
		Refrigerant charge is low.	Call service to find and repair
		Refrigerant charge is low.	the leak. Add refrigerant.
			the leak. Add refrigerant.
	Pump pressure is too high.	Restricted water flow.	Check for partially closed
	Pump pressure is too high.	Restricted water flow.	valves etc. Be sure all lines
			are properly sized.

SCW Series Central Chilling Stations

Page 69 of 77

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Sterling SCW Series installation manual Problem Possible Cause Solution

Contents

SCW Series Central Chilling Stations SCW Series Central Chilling Stations Wear Safety Glasses and Work Gloves Safety Considerations Table of Contents Indicator Lights and Control Switches MMI Startup Checklists Viewing and Operating Chiller Pumps Charts and Figures Necessary Documents Introduction Models Covered Standard Features Available Options Standard Features on Remote Condensers Model Number Nomeclature Nominal water flow gpm Typical Two-Circuit 60-195 Ton Water Cooled Chiller 460/3/60 Vf 460/3/60 Typical Two-Circuit 60-195 Ton Remote Air Cooled Chiller Scwr Series Remote Condenser Models Event of Shipping Damages Unpacking and Inspection If the Shipment is Not Correct If the Shipment is Not CompleteReturns Bill of lading Packing list Uncrating Your New Chiller SCW Series Central Chilling Stations Making Electrical Connections Installation Location Considerations Check Compressor Rotation Before Starting Unit Piping Considerations Making Process Water ConnectionsTo Process Making Tank Piping Connections Galvanic Corrosion Considerations Water Connection Sizing ConsiderationsWater Treatment Considerations Making Water-Cooled Condenser Connections Installing the Remote Air-Cooled Condenser Condenser WaterCondenser Water Out Checking Motor Direction CompressorWater Pump Condenser Fan Staging AlarmsLead-Lag Compressors Lead-Lag Pumps Chilled Water Circuit Refrigeration CircuitFreezestat Control Percent by Freezing Protection Curve High pressure cutout setting Flow SwitchHigh Pressure Cutout Low Pressure Cutout Control Probe Control NozzleChilled Water Manifold Optional Condenser Water Manifold SCW Series Central Chilling Stations Water-Cooled SCW Series Startup Checklist Startup Checklists SCW Series Central Chilling Stations Water-Cooled SCW Series Startup Remote Air-Cooled SCW Series Startup Checklist SCW Series Central Chilling Stations Fan Set on Set off Number Psi KPa Bars Remote Air-Cooled SCW Series Startup Shutdown Determining Flow Rate Graphic Panel Devices Indicator Lights and Control Switches MMI SCW Series Central Chilling Stations Using the Standard Operator InterfaceOperator Interface Introduction SCW Series Standard Control Panel Using the SCW Series Standard Operator Interface Viewing and Operating Chiller Pumps Viewing and Setting System Temperatures Viewing Active Alarms and Handling Alarm Conditions Setting System Temperatures Using the Advanced Touchscreen InterfaceTouchscreen Interface Introduction MMI Using the SCW Series Advanced Touchscreen Interface Main Menu Screen Viewing Compressor Status Chiller Status Screen Chiller Configuration Screen SCW Series Central Chilling Stations Compressor Run Time Display Screen Viewing Chiller Pump Status Pump Status Screen Pump Enables Screen Pump Run Time Display Screen Pumps Alarm Condition Screen Viewing and Setting System Temperatures System Status Screen Temperature Input Display Screen Lubrication Condenser MaintenanceRemote Air-Cooled Water-Cooled Pump Motor Seal Evaporator MaintenanceMakeup Valve Recommended Pump Tank Spare Parts Preventive Maintenance Service SCW Series Central Chilling Stations Troubleshooting Problem Possible Cause Solution Verify proper rotation if Service Notes Determining Flow Rate Index SCW Series Central Chilling Stations Service Notes Service Notes Service Notes Parts Department Technical Assistance