Sterling A0554831 Safety Devices and Interlocks, High/Low Thermostat Control, Crankcase Heater

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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 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 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 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 360 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 CutoutFan Cycling Switch Pressure SwitchFlow Switch Low Pressure CutoutOptional 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 DescriptionE5CK See Figure Indicator Name Description Graphic PanelIndicator Name Description Typical Graphic Panels With E5CK Controller Eurotherm 3216 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 Returns AppendixReturned Material Policy Credit ReturnsService 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 28.3 22.0 41.7 28.3 22.0 41.7Hp 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 Water-Cooled Portable Chillers 39.5 39.1 98.481.9 63.1 85.0 66.2 Hp and 7.5 hp Remote Air-Cooled Portable Chillers Hp and 15 hp Remote Air-Cooled Portable Chillers Nominal cooling ComIn. dia. ODS Pump Pumps Discharge Liquid Rated Running 15.0 40.9 34.0 74.7Hp through 40 hp Remote Air-Cooled Portable Chillers Nominal cooling Com RefrigerationPres Nom Connections 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 Evaporator Water Pressure Drop Tables Calculating Chiller Nominal Flow and Pressure to ProcessRecirculation Pump Specifications Recirc. power Flow Rate Pressure Gpm Lpm Psi KPaEvaporator Flow and Pressure Considerations Remote Air-Cooled Chiller Configurations 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 Typical Electrical Subpanel

A0554831 specifications

The Sterling A0554831 is a versatile and powerful tool designed for a range of applications, particularly in the industrial and construction sectors. Known for its robust construction and reliability, it has gained popularity among professionals and DIY enthusiasts alike.

One of the main features of the Sterling A0554831 is its durable build quality, which is designed to withstand harsh working conditions. The device typically features a high-strength casing that protects it from dust, moisture, and impact, ensuring longevity even in the most demanding environments. Its ergonomic design allows for comfortable handling, minimizing user fatigue during extended use.

In terms of performance, the Sterling A0554831 is equipped with advanced technologies that enhance its efficiency and functionality. The device is powered by a high-torque motor, delivering impressive power that enables it to tackle heavy-duty tasks with ease. The precision-engineered components ensure consistent performance, making it ideal for tasks that require accuracy and reliability.

Another significant characteristic of the Sterling A0554831 is its versatility. It typically comes with multiple settings and modes, allowing users to adjust the tool according to the specific requirements of their project. Whether drilling, cutting, or fastening, the tool can accommodate various tasks, making it a valuable addition to any toolkit.

Safety features are also a priority with the Sterling A0554831. Many models are equipped with overload protection and safety switches that prevent accidental activation, safeguarding the user during operation. Additionally, some variants may include LED indicators that provide real-time information about battery life or operational status, enhancing overall user experience.

In conclusion, the Sterling A0554831 stands out in the market for its combination of durability, performance, and versatility. With advanced technologies that cater to a wide range of applications and a design focused on user comfort and safety, this tool is an excellent choice for professionals looking for dependable and effective solutions in their work. Whether you are a seasoned professional or a casual DIYer, the Sterling A0554831 is well-equipped to handle your needs with ease and efficiency.
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