Siemens SIRIUS 3RS2 Temperature Monitoring Relays

Siemens SIRIUS 3RS2 Temperature Monitoring Relays Suppliers,Exporters in India

ARP IMPEX is a supplier and exporter of Siemens SIRIUS 3RS2 Temperature Monitoring Relays in India. We handle requirements for motors, transformers, bearings, industrial ovens, process equipment, HVAC systems, control panels and replacement of older Siemens 3RS1 relays.

The Siemens 3RS2 range monitors temperature through an external resistance sensor, thermocouple or compatible temperature transmitter. When the measured temperature rises above or falls below the set limit, the relay changes the state of its output contacts. The contact can stop a machine, switch a heater or cooling fan, operate an alarm or send a signal to the control system.

These relays are useful where temperature provides a better indication of equipment condition than current or voltage. A motor bearing, transformer winding, gearbox oil circuit or cooling system may begin overheating even though the electrical load still appears normal.

The 3RS2 family includes simple analogue relays for one temperature limit, digital relays with a display and two adjustable limits, and IO-Link versions for transmitting measured values and diagnostic information to a higher-level controller. Siemens also offers a sensor expansion module for applications requiring additional resistance sensors or a 4–20 mA temperature input.

For Siemens SIRIUS 3RS2 Temperature Monitoring Relay price and availability, share the complete Siemens article number, required quantity and destination country.

Siemens 3RS2 Product Range

Siemens 3RS25 Analogue Temperature Monitoring Relays

The Siemens 3RS25 range is suited to straightforward temperature monitoring where one sensor and one adjustable limit are sufficient.

Settings are made from the front of the device using rotary and slide controls. Depending on the selected model, the user can set the trip temperature, sensor type, measuring range, hysteresis and whether the relay should operate when the temperature exceeds or falls below the set limit.

The analogue range supports Pt100 resistance sensors and Type J or Type K thermocouples, depending on the exact part number. It can also work as a simple two-position temperature controller for switching heating or cooling equipment.

Typical requirements include:

• Siemens 3RS2500 temperature monitoring relays
• Pt100 temperature relays for control panels
• Type J thermocouple monitoring relays
• Type K thermocouple monitoring relays
• Overtemperature and undertemperature relays
• Simple heating and cooling control relays
• Siemens 3RS26 Digital Temperature Monitoring Relays

The Siemens 3RS26 provides a front display and a wider choice of sensors, limits and operating modes. It can monitor temperature above a set point, below a set point or within a defined operating window.

Two limit values can be used for separate warning and shutdown stages. For example, the first output may operate an alarm when a bearing starts becoming hot, while the second output stops the machine if the temperature continues to rise.

The 3RS26 supports common resistance sensors and thermocouples, including Pt100, Pt1000, KTY83, KTY84, selected NTC sensors and thermocouple Types J, K, T, E, N, S, R and B. Manual, automatic and remote reset options are available according to the settings and operating mode.

The display changes its background indication according to the operating condition, giving the panel operator a quick view of normal operation, warning or fault status.

Siemens 3RS28 Temperature Monitoring Relays with IO-Link

The Siemens 3RS28 range combines digital temperature monitoring with IO-Link communication.

The relay can continue monitoring and operating its local output contacts independently while also sending temperature values, warnings and diagnostic information to the PLC or higher-level control system.

Parameters can be adjusted remotely, and the controller can store the device settings for faster replacement of an identical relay.

This range is useful for:

• Automated production lines
• Machines connected to a PLC
• Predictive maintenance systems
• Remote temperature monitoring
• Centralised plant diagnostics
• Control panels requiring IO-Link devices
• Projects requiring easier parameter backup and device replacement

The Siemens 3RS2800 range uses a 24 V DC supply and is available with screw or spring-type terminal options, depending on the full article number.

Siemens 3RS29 Sensor Expansion Module

The 3RS29 expansion module is fitted next to an applicable 3RS26 or 3RS28 digital relay.

It adds:

• Two resistance-temperature sensor inputs
• One additional relay output for sensor status
• One 4–20 mA analogue temperature input

A digital relay normally monitors one sensor. With the expansion module, it can monitor up to three resistance sensors. Communication between the basic relay and expansion module takes place through an infrared interface, so no separate communication wiring is needed between the two devices.

This arrangement is useful for three-phase motors, transformers and machines where temperature must be checked at several points.

Technical Specifications

The 3RS2 is a product family, so the exact values depend on the selected Siemens article number.

• Brand: Siemens
• Product range: SIRIUS
• Series: 3RS2
• Product type: Temperature monitoring relay
• Measured media: Solid, liquid and gaseous media
• Main versions: Analogue, digital and digital with IO-Link
• Analogue series: 3RS25
• Digital series: 3RS26
• IO-Link series: 3RS28
• Sensor expansion module: 3RS29
• Monitoring: Temperature overshoot, undershoot or window monitoring
• Analogue sensor options: Pt100 and Type J or K thermocouples
• Digital resistance sensors: Pt100, Pt1000, KTY83, KTY84 and selected NTC sensors
• Digital thermocouples: Types J, K, T, E, N, S, R and B
• Analogue input: 4–20 mA through an applicable 3RS29 expansion module
• Number of sensors: One as standard; up to three resistance sensors with expansion
• Adjustable limits: One on analogue models and two on digital models
• Trip delay: Adjustable on digital versions
• Reset: Automatic, manual or remote on applicable digital versions
• Display: LCD on 3RS26 and 3RS28 versions
• Communication: IO-Link on 3RS28 models
• Output contacts: Depend on the complete part number
• Supply voltage: 24–240 V AC/DC on applicable models; 24 V DC on IO-Link versions
• Enclosure width: 22.5 mm
• Enclosure depth: Approximately 90 mm
• Connection options: Screw or spring-type push-in terminals
• Mounting: Standard DIN rail
• Standards and approvals: Depend on the selected model and application

The 3RS2 digital relays allow adjustable hysteresis and configurable on-delay and trip-delay times. The exact measuring range depends on the connected sensor; for example, Siemens specifies a range of –50°C to +750°C for Pt100 inputs on the digital models.

Features

• Monitors temperature directly through an external sensor
• Suitable for solids, liquids and gases
• Provides a warning or shuts down when a limit is crossed
• Can monitor both rising and falling temperatures
• Window monitoring keeps the temperature within an approved range
• Separate warning and trip limits on digital versions
• Supports resistance sensors and thermocouples
• Optional 4–20 mA temperature-transmitter input
• Monitors sensor wiring for short circuit and wire break on applicable models
• Digital display provides the measured value and operating status
• A colour-changing display helps identify warnings and faults
• Adjustable hysteresis prevents frequent output switching near the limit
• Adjustable delay helps avoid operation during brief temperature changes
• Manual, automatic and remote reset options
• IO-Link versions transmit measurements and diagnostics to the controller
• Parameter backup simplifies the replacement of IO-Link devices
• Sensor expansion allows monitoring at up to three points
• Compact 22.5 mm width saves control-panel space
• Screw and push-in terminal versions are available
• Can operate as a temperature monitor or a simple heating/cooling controller
• Suitable for new control panels and 3RS1 replacement projects

Siemens offers selected 3RS2 configurations for safety-related monitoring up to SIL 1/PL c and for industrial furnace, burner and ATEX-related applications. The correct certification, sensor arrangement and accessory requirements must be verified against the complete article number; ATEX-related monitoring through a 4–20 mA input requires the applicable 3RS29 expansion arrangement.

Applications

Siemens SIRIUS 3RS2 Temperature Monitoring Relays are used for:

• Electric motor temperature monitoring
• Motor winding temperature protection
• Motor bearing temperature monitoring
• Large three-phase motor monitoring
• Transformer winding temperature monitoring
• Transformer oil temperature monitoring
• Gearbox and transmission oil monitoring
• Pump-bearing temperature monitoring
• Compressor temperature monitoring
• Industrial fan and blower monitoring
• Machine-tool temperature supervision
• Process tank temperature monitoring
• Cooling-water temperature monitoring
• Refrigeration and chiller systems
• Control-cabinet temperature monitoring
• Industrial oven and furnace monitoring
• Burner temperature supervision
• Exhaust-gas temperature monitoring
• HVAC and ventilation systems
• Frost protection systems
• Heat pumps
• Solar collectors
• Hot-water systems
• Packaging machines
• Electroplating plants
• Marine and shipbuilding applications
• Railway equipment
• Industrial control and automation panels

Siemens identifies control cabinets, motors, bearings, gear oil, coolants, HVAC systems, solar collectors, heat pumps, hot-water systems, rail and shipbuilding among the applications for this range.

3RS2 for Motor and Transformer Temperature Monitoring

The 3RS2 does not measure motor current like an overload relay. It monitors the temperature measured by the connected sensor.

For a motor, sensors may be installed near the windings or bearings. The relay can issue an early warning when the temperature begins rising and stop the motor at a higher limit.

For a transformer, separate sensors can monitor windings, oil or bearing temperatures. An applicable 3RS26 or 3RS28 relay with a 3RS29 expansion module can monitor up to three resistance sensors, making it useful where several temperature points must be checked through one relay.

The correct sensor type and temperature range should follow the equipment manufacturer’s recommendation.

Siemens 3RS1 Replacement with 3RS2

The Siemens SIRIUS 3RS2 family replaced the earlier 3RS1 temperature monitoring relay range. However, a new 3RS2 model should not be selected only by comparing the first digits of the two series.

A replacement assessment should check:

• Existing 3RS1 article number
• Connected sensor type
• Temperature measuring range
• Number of warnings and trip limits
• Supply voltage
• Output contact arrangement
• Overshoot or undershoot monitoring
• Reset requirement
• Screw or spring-type terminals
• Required safety or ATEX approval
• Available panel space

The 3RS2 has a narrower 22.5 mm housing and may provide functions that were previously spread across several 3RS1 variants. Panel wiring and terminal positions should still be checked before replacement.

Selecting the Correct Siemens 3RS2 Relay

A request for “Siemens 3RS2 Temperature Relay” does not identify a complete product.

For an accurate quotation, share:

• Complete Siemens article number
• Required quantity
• Destination country
• Sensor type
• Required temperature range
• Supply voltage
• Required output contacts
• Analogue, digital or IO-Link requirement

For replacement requirements, also send a clear photograph of the existing relay label and front terminal markings.

If the article number is unavailable, confirm whether the relay will monitor a Pt100 sensor, thermocouple, NTC/KTY sensor or 4–20 mA temperature transmitter.

Siemens SIRIUS 3RS2 Temperature Monitoring Relay Supplier and Exporter in India

ARP IMPEX supplies Siemens SIRIUS 3RS2 Temperature Monitoring Relays for panel builders, machine manufacturers, industrial plants, EPC contractors, maintenance companies and export buyers.

We handle enquiries for:

• Siemens 3RS25 analogue temperature relays
• Siemens 3RS26 digital temperature relays
• Siemens 3RS28 IO-Link temperature relays
• Siemens 3RS29 sensor expansion modules
• Pt100 temperature monitoring relays
• Thermocouple monitoring relays
• Motor and bearing temperature relays
• Transformer temperature monitoring relays
• Industrial furnace temperature relays
• Siemens 3RS1 replacement requirements
• Temperature relays with warning and trip outputs
• IO-Link temperature monitoring devices

The Siemens 3RS2 price depends on the complete part number, sensor input, temperature range, supply voltage, output arrangement, terminal type and IO-Link requirement.

Send the complete Siemens part number, required quantity and destination country for price, availability and export quotation.