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This temperature monitor provides continuous thermal measurement for critical machinery protection. It accepts resistance temperature detectors and thermocouple inputs for accurate readings. The module fits directly into the Bently Nevada 3300 rack monitoring system.
Technical Specifications
| Parameter | Specification |
|---|---|
| Model Number | 3300/35 |
| Product Type | Temperature Monitor |
| Supply Voltage | 24 V DC ±10% |
| Power Consumption | 8 W (maximum) |
| Input Channels | 6 (RTD or thermocouple, independent) |
| RTD Type | 3-wire Pt100 (-50°C to +250°C) |
| Thermocouple Types | J (0°C to +750°C), K (0°C to +1200°C) |
| Resolution | 16-bit |
| Accuracy | ±0.2% of full scale (at 25°C) |
| Outputs | 6 x 4–20 mA (isolated, scalable) |
| Alarm Relays | 4 x Form C (SPDT, 2 A at 30 V DC) |
| Communication | 1 x RS-485 (Modbus RTU) |
| Cold Junction Compensation | Built-in, software-calibrated |
| LED Indicators | 6 (Power, OK per channel) |
| Mounting | Backplane (3300 rack) |
| Dimensions (W x H x D) | 26 mm x 223 mm x 175 mm |
| Weight | 0.45 kg |
Mechanical Construction and Rack Integration
This monitor module uses the standard 26 mm wide 3300 series form factor. It occupies one slot within the rack and connects via the backplane. The module weighs 0.45 kilograms and has a sturdy metal faceplate. All necessary connections and indicators are accessible from the front.
Power Supply and Electrical Requirements
The device requires a 24 V DC supply with a tolerance of ±10%. Maximum power consumption reaches 8 watts under normal operating conditions. Internal protection includes reverse polarity and overvoltage limiting. The module does not require external sensor excitation.
Input Channels and Sensor Compatibility
This module features six separate input channels for temperature sensors. Each channel accepts either a 3-wire Pt100 RTD or a thermocouple. The RTD input covers a range from -50°C to +250°C. The thermocouple inputs support J and K types for high-temperature applications. Users can configure each channel individually via software.
Measurement Performance and Accuracy
The system measures temperature with 16-bit resolution for detailed readings. Accuracy is ±0.2% of full scale at an ambient temperature of 25°C. The built-in cold junction compensation ensures accurate thermocouple measurements. This design guarantees reliable thermal data for critical machinery.
Output Signals and Alarm Functions
Six isolated 4–20 mA outputs provide continuous temperature data to external systems. Each output can be scaled independently to match specific application needs. Four form C relays supply alert and danger alarms. The relays are rated for 2 A at 30 V DC.
Communication Interface
An RS-485 serial port facilitates remote communication using the Modbus RTU protocol. This connection allows for configuration, monitoring, and data retrieval. Users can remotely access temperature values and alarm states. The module also logs peak readings for long-term trend analysis.
Diagnostics and Status Indication
Six front-panel LEDs immediately convey the module’s operational state. A green Power LED confirms that the supply voltage is present. Individual OK LEDs indicate proper sensor operation for each channel. A flashing LED signals a sensor fault or out-of-range condition.
Application Areas
This temperature monitor is suitable for a wide range of rotating machinery. Typical applications include turbines, compressors, pumps, and generators. It also monitors bearings, windings, and process fluids. The device operates effectively between -20°C and +65°C.