Temperature Sensor MCS, LP Switch, HP 200 to 500°F TI-100 For Chiller
Temperature Sensor MCS, LP Switch, HP 200 to 500°F, and TI-100 – Critical Components for Efficient Chiller Systems
Industrial chillers rely on an array of electronic and mechanical sensors and switches to maintain safe and efficient operation. Among the most crucial are the temperature sensor (MCS), LP (Low Pressure) switch, HP (High Pressure) switch rated 200 to 500°F, and TI-100 sensors. These components play pivotal roles in ensuring a chiller system operates within optimal parameters and shuts down when unsafe conditions arise.
In this article, we will explore each of these devices in detail, understand their functions in a chiller system, discuss their specifications and compatibility, and provide practical insights into installation, calibration, and troubleshooting.
1. Introduction to Chiller Monitoring and Control Components
Chillers are complex systems designed to remove heat from a process or environment.
The performance, safety, and longevity of a chiller heavily depend on precision monitoring and control. Components like temperature sensors (MCS & TI-100) and pressure switches (LP and HP) ensure real-time measurement and response to critical conditions like temperature spikes or pressure fluctuations.
2. MCS Temperature Sensor for Chillers
2.1 What is an MCS Temperature Sensor?
The MCS (Micro Control Systems) temperature sensor is a highly reliable electronic sensor designed for use in HVAC and refrigeration systems. It provides accurate temperature readings and is commonly used in chillers to monitor:
Suction and discharge line temperatures
Water/glycol fluid outlet and inlet temperatures
Ambient and room temperatures
2.2 Features of MCS Temperature Sensors
Precision: Typically accurate to ±0.5°F (±0.3°C)
Material: Stainless steel or corrosion-resistant plastic casing
Thermistor Type: Commonly 10kΩ NTC at 77°F
Connection Type: 2-wire thermistor, suitable for direct PLC or controller input
Response Time: Fast thermodynamic response for real-time monitoring
2.3 Applications in Chiller Systems
Monitoring evaporator and condenser temperatures
Ensuring outlet water stays within set parameters
Feedback to chiller control logic for VFD or stepwise compressor operation
Protecting the compressor from overheating
3. LP (Low Pressure) Switch – Function and Importance
3.1 What is an LP Switch in a Chiller?
The LP (Low Pressure) switch is a safety device that monitors the suction pressure (low side) of the refrigerant circuit. If the pressure drops below a safe threshold, the switch trips to shut down the compressor and prevent damage.
3.2 Technical Specifications
Range: Usually adjustable between 10 to 90 psi
Type: Normally closed (NC) or normally open (NO), depending on design
Reset Mechanism: Manual or automatic
Mounting: Threaded 1/4″ or 3/8″ SAE flare or NPT connections
3.3 Common Causes for LP Switch Trips
Low refrigerant charge or leaks
Blocked evaporator
Dirty filters or restricted airflow
Expansion valve issues
3.4 Benefits of an LP Switch
Protects the compressor from dry running or freeze-up
Prevents short-cycling during low-load conditions
Acts as a diagnostic indicator for system health
4. HP (High Pressure) Switch Rated 200 to 500°F – Protecting the High Side
4.1 What is a High Pressure Switch?
An HP switch is used to monitor the high side (discharge) pressure or temperature of the refrigerant. The 200°F to 500°F range switch is typically thermally actuated and is designed to trip if discharge temperature rises beyond safe limits.
4.2 Temperature-Based HP Switches vs Pressure Switches
Temperature HP Switch: Senses the temperature directly, often used on discharge lines
Pressure HP Switch: Senses pressure in the condenser circuit
200°F to 500°F Range: Specifically designed for high-temperature refrigerants and synthetic oils in scroll and screw compressors
4.3 Applications in Chillers
Mounted on discharge lines of compressors
Connected to the controller or relay logic to initiate alarms or shutdowns
Used in scroll, screw, or centrifugal compressor chillers
4.4 Common Tripping Causes
Fouled condenser coils
Blocked refrigerant flow
High ambient temperature
Cooling tower or fan failure
4.5 Reset Options
Manual Reset: Enhances safety by requiring human inspection
Automatic Reset: Used where temporary spikes occur but not persistent faults
5. TI-100 Temperature Indicator/Sensor – Versatile and Accurate
5.1 What is the TI-100?
The TI-100 is an industrial-grade temperature indicator, often thermocouple or RTD-based, used for real-time temperature monitoring in chillers and other industrial equipment. It can be panel-mounted or built-in and typically displays readings on an LED/LCD screen.
5.2 Key Features
Display: Bright LED/LCD with Fahrenheit and Celsius options
Sensor Input: PT100 RTD, Type-K or Type-J thermocouple
Accuracy: ±0.2% of reading
Range: -50°F to +1000°F, configurable
5.3 Applications in Chillers
Monitoring hot gas bypass lines
Displaying outlet and return water/glycol temperature
Used by operators for real-time system adjustments
Integrated with PLC for automated control
5.4 Mounting and Wiring
DIN panel mounting
24V or 230V AC/DC input
2 or 3-wire RTD connection or thermocouple input
6. Integration of All Components in a Chiller System
Component Function Typical Location Connected To
MCS Temp Sensor Water/glycol or refrigerant temperature measurement Inlet/Outlet lines, Evaporator/Condenser PLC or Controller
LP Switch Suction pressure monitoring Compressor low side Control Panel
HP Switch (200°F to 500°F) Discharge temperature or pressure monitoring Compressor high side Safety Circuit
TI-100 Display and monitor temperature Panel or near unit Sensor Input (RTD/Thermocouple)
Together, these components contribute to:
System Safety – Preventing compressor damage and system failure
Efficiency – Ensuring optimal load matching and energy savings
Automation – Allowing smart logic control and remote monitoring
Diagnostics – Easy fault tracing and maintenance
7. Installation Best Practices
7.1 MCS & TI-100 Temperature Sensors
Use thermal paste for better contact
Ensure good insulation to avoid ambient interference
Calibrate with known temperature sources during commissioning
7.2 Pressure Switches (LP and HP)
Install vertically where possible to avoid false readings
Use proper torque and sealing during fitting
Verify trip points and reset mechanisms
8. Troubleshooting and Maintenance Tips
Symptom Likely Cause Action
TI-100 showing error Sensor disconnected or failed Check wiring, replace sensor
LP switch tripping frequently Refrigerant leak or blockage Inspect pressure, fix leaks
HP switch trip on start-up High ambient temp or fan fault Improve cooling, service fans
MCS temp sensor giving wrong values Calibration drift or sensor damaged Replace or recalibrate
9. Sourcing and Compatibility in India
As a leading chiller manufacturer and supplier in India, Reynold India offers compatibility with:
MCS 10kΩ sensors
LP switches with adjustable settings
HP switches designed for scroll/screw compressors
TI-100 digital displays with wide-range sensor support
We recommend sourcing original, branded components to avoid system mismatch and ensure long-term reliability.
10. Conclusion
The MCS temperature sensor, LP switch, HP 200°F to 500°F thermal switch, and TI-100 temperature indicator are not just auxiliary parts—they are the brain and nerve system of a chiller. They ensure precision control, safety, and long service life of the chiller.
For OEMs, maintenance engineers, and HVAC consultants, understanding these components’ roles and integrating them properly ensures the smooth operation of industrial cooling systems.
Need OEM-Grade Sensors or Switches?
At Reynold India, we supply and integrate high-quality, durable, and field-tested components for all chiller types. Whether you’re replacing a failed sensor or designing a new system, contact us for:
✅ MCS Temperature Sensors
✅ LP and HP Safety Switches
✅ TI-100 Digital Indicators
✅ Complete Control Panel Solutions
📞 Call Now: +91-123-456-7890
🌐 Visit: www.reynoldindia.com
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