HP A0554832 manual Safety Devices and Interlocks, High/Low Thermostat Control, Crankcase Heater

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•Three year limited controller warranty

2-4 Safety Devices and Interlocks

High/Low Thermostat Control

The high/low thermostat is a cutout device that protects the chiller system in two ways. Stage one of the thermostat shuts down the compressor if the chilled process water/glycol temperature approaches the particular mixture’s freezing point. The chilled process water/glycol pump will continue to run.

The high/low thermostat stage one cutout temperature is factory-set at 42ºF (5.5ºC). This is correct for a supply water temperature of 50ºF (10ºC), the rated capacity operating temperature. If you want lower chilled water temperatures, mix process water with glycol to provide protection down to 20ºF (11ºC) below the operating “To Process” temperature you want. You can then reset the high/low thermostat cutout temperature to a temperature 8ºF (4.4ºC) below the operating temperature you want.

Stage two of the high/low thermostat shuts down the pumps, therefore shutting off the chiller, if the chilled process water/glycol temperature rises above the selected cutout point. This prevents possible damage to the complete process piping system due to overheating of the components by the process water/glycol. The thermostat stage two cutout temperature is factory set at 100ºF (38ºC). See Section 4-6 on page 36 for information about changing the thermostat settings.

Caution! Protect the system from freezing with glycol 20ºF below the leaving water temperature set point. Condensation may form inside the pump tank and dilute the mixture, therefore the freezing point should be verified periodically. See Figure 6 on page 26 for the correct mixture.

Caution! Set high/low thermostat cutout temperature 8ºF below the set point leaving water temperature.

Crankcase Heater

5 hp through 40 hp portable chillers have a crankcase heater. It is wired through the control transformer that operates continuously whenever power is applied to the chiller.

Caution! Energize the crankcase heater for at least 24 hours before initial startup to drive dissolved refrigerant from the compressor oil. Failure to do so will damage the compressor.

High Pressure Cutout

This electro-mechanical cutout device opens the compressor control circuit if the refrigeration system compressor discharge pressure exceeds 375 psi for an air-cooled chiller and 290 psi for a water-cooled chiller.

Note: The high-pressure cutout is a manual reset device typically mounted on the compressor discharge line inside the mechanical cabinet. Call a refrigeration service technician to analyze the problem and reset the control.

2-40 HP Portable Chillers

Chapter 2: Functional Description

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Contents Hp Portable Chillers Shipping Information Table of Contents Operation HP Portable Chillers Safety How to Use This ManualSafety Symbols Used in this Manual Wear Safety Glasses and Work Gloves ResponsibilityFunctional Description Models Covered in This ManualGeneral Description Chilled Water CircuitRefrigeration Circuit Standard Features Mechanical FeaturesOther Mechanical Features Electrical Features Refrigeration FeaturesController Features Other FeaturesSafety Devices and Interlocks High/Low Thermostat ControlCrankcase Heater High Pressure CutoutOil Pressure Safety Switch Fan Cycling SwitchPressure Switch Flow SwitchOptional Features Mounting Features Optional Pump Amperages Voltage Construction Full Load Amps Installation UncratingElectrical Connections Process Water Connections Bypass Valve ConsiderationsGalvanic Corrosion Considerations Water Treatment ConsiderationsCondenser Considerations Water-Cooled Chiller CondensersAir-Cooled Chiller Condensers Remote Air-Cooled Chiller Condensers Page Equivalent Length in Feet for Valves and Fittings Chiller Condenser Charge Field Installed Piping Charge Refrigerant Charge DeterminationThree-Phase Compressors Checking Motor DirectionWater Pumps Condenser FanWater Reservoir Part Number DescriptionEthylene Glycol and Propylene Glycol Curves Automatic Water Make-Up Option Initial Start-Up Panel Buttons, Indicator Lights, and Switches E5CK Controller Indicator Name DescriptionOperation Microprocessor ControllersIndicator Name Description Sterlco 2000 Controller Indicator Name Description2000 See on Indicator Name Description Graphic PanelIndicator Name Description Typical Graphic Panels With E5CK Controller With Sterlco 2000 ControllerSetting the Process Water Temperatures Auto-TuningStart-up Optional CommunicationsThermostat Buttons Indicator Name Description Programming the Electronic High/Low ThermostatStage 2 High Temperature Protection Select Fahrenheit or CelsiusStage 1 Freeze Protection Maintenance Filter CleaningLubrication Maintaining the Condenser Maintaining the EvaporatorEvaporator Process Piping Y-Strainer Air- and Remote Air-Cooled ChillersPreventative Maintenance Service Troubleshooting HP Portable Chillers TroubleshootingHP Portable Chillers Troubleshooting Warranty AppendixService Department Technical AssistanceParts Department Sales DepartmentDrawings and Specifications Hp and 3 1/2 hp Air-Cooled Portable ChillersHp and 7.5 hp Air-Cooled Portable Chillers Hp and 15 hp Air-Cooled Portable Chillers 20 hp, 25 hp, and 30 hp Air-Cooled Portable Chillers Hp and 3.5 hp Water-Cooled Portable Chillers Nominal Condenser water Nominal cooling Water ComIn. NPT Height Width Depth Lbs Hp and 7.5 hp Water-Cooled Portable Chillers Hp and 15 hp Water-Cooled Portable Chillers 20 hp, 25 hp, and 30 hp Water-Cooled Portable Chillers Hp and 40 hp Water-Cooled Portable Chillers Nominal cooling Com Refrigeration Power in amps e Hp and 7.5 hp Remote Air-Cooled Portable Chillers12.8 17.3 748Hp and 15 hp Remote Air-Cooled Portable Chillers Nominal cooling Com RefrigerationPres Nom Connections 15.0 40.9 34.0 74.7Hp through 40 hp Remote Air-Cooled Portable Chillers To/from No tank Tank, to/from Height Width Depth LbsRemote Condenser Assembly Models ‘A’in ‘B’in ‘C’in ‘D’in ODSinPump Curves, Flow, and Pressure Considerations Hertz Pump CurvesDWG. No. S0554823 Water Pressure Drop Tables Calculating Chiller Nominal Flow and Pressure to ProcessRecirculation Pump Specifications Recirc. power Flow Rate ∆ pressure Gpm Lpm Psi KPaFlow and Pressure Considerations Remote Air-Cooled Chiller Configurations Configuration aConfiguration B Configuration C Typical Ductwork for Air-Cooled Chillers Piping Diagrams Central and Gravity Return Piping with Standpipe DiagramTypical Piping Schematic, 2 and 3 1/2 hp Models HP Portable Chillers Appendix HP Portable Chillers Appendix Typical Piping Schematic, 5 hp through 40 hp, No-Pump Models HP Portable Chillers Appendix Electrical Schematics Time-delay Relays Disconnect Switch OptionalTypical Electrical Subpanel Speed FusesTypical Electrical Schematic, 2 hp and 3 1/2 hp Models Typical Power Wiring Schematic, 5 hp through 40 hp Models A0554815HP Portable Chillers Appendix DWG A0554931 DWG A0562343 DWG A0562435 Typical Wiring Schematic, 35 hp and 40 hp Models with Pump DWG A0562434
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