Problem Possible cause Solution | Sterling A0544325 guide

	Problem	Possible cause	Solution
		Refrigerant is low.	Check the refrigerant charge.
		Pressure switch contacts are	Sight glass should be clear
		Pressure switch contacts are	while compressor runs. Call
		open.	for service if bubbling or
			foaming.
		Refrigerant high pressure	Check for dirty condenser.
		cutout switch contacts are	Check for condenser air
	Pump runs, compressor will	open.	obstruction.
	not.	Defective fan motor.	Repair or replace.
		Compressor internal overload	Check for high/low voltage.
		Compressor internal overload	Must be within plus or minus
		is open. Allow time to cool	10% of the nameplate rating.
		and reset.	Check for poor compressor
			electrical connections.
		Broken wire in the	Locate and repair.
		compressor control circuit.	Locate and repair.
		compressor control circuit.
		Restricted condenser airflow.	Clean the condenser.
	Unit runs continuously, but	Unit low on refrigerant.	Call Service.
	Unit runs continuously, but	Inefficient compressor.	Call Service.
	not enough cooling power.	Inefficient compressor.	Call Service.
	not enough cooling power.	Unit undersized for	Call Sales Representative.
		Unit undersized for
		application.
		application.

Page 34		SMC Series Chillers

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Sterling A0544325 installation manual Problem Possible cause Solution

Contents

SMC-050 to SMC-150 Series SMC Series Chillers Safety Considerations Table of Contents Table of Contents Charts and Figures Necessary Documents General InformationIntroduction Models Covered Available Options Uncrating Your New Chiller If the Shipment is Not Complete Event of Shipping DamagesIf the Shipment is Incorrect SMC050A Process Pump Curves ReturnsSMC100A Process Pump Curves SMC150A Process Pump Curves SMC Series Chiller Specifications SMC-150 25,400 16,000 12A 345 Electrical Connections Chiller InstallationProcess Water Connections SMC Condenser Air Supply Water Reservoir Ethylene Glycol Curve Overhead Process Considerations Overhead Piping Chilled Water Circuit Sequence of OperationRefrigeration Circuit Low Pressure Cutout High Pressure CutoutRemote Start/Stop Interlock SMC Component Identification Piping Schematic 1 Pump with Reservoir End of unit piping Piping Schematic 1 Pump without Reservoir Piping Schematic No Pump, No Reservoir SMC Pre-Startup Checklist SMC Startup Checklist SMC Water Circuit Pressure Drop Table Setting the Alarm Value Setting the Process Water TemperatureMicroprocessor Control SMC Control SP AL Switches Indicator LightsOptional Graphic Panel SMC Series Optional Graphic Panel Lubrication Routine MaintenanceCondenser Maintenance Typical SMC Subpanel Typical SMC Wiring Schematic SMC Wiring Schematic for Chillers with No Pump or Reservoir SMC Series Chillers Troubleshooting Guide Problem Possible cause Solution Problem Possible cause Solution SMC Spare Parts List Description Service Notes Service Notes Milwaukee, WI Sterling/Sterlco5200 West Clinton Avenue 414 Fax 414