Description
1. Product Title
Schischek EXL-IRU-1 – ATEX Switching Module with Ex-i Circuit
2. Product Overview
The EXL-IRU-1 is a specialized explosion-proof switching module manufactured by Schischek (a brand under the Rotork group). Its primary function is to act as an intrinsically safe (Ex-i) interface between passive binary sensors located in hazardous areas and control systems in safe areas. In industrial environments such as chemical plants or oil rigs, standard electrical signals can trigger explosions; the EXL-IRU-1 solves this by limiting the energy sent to the field device, ensuring it remains below the ignition threshold. It typically processes signals from potential-free sensors (like thermostats, pressure switches, or humidity sensors) and provides a relay output to the DCS or PLC, making it a critical safety barrier for HVAC and process automation in volatile atmospheres.
3. Technical Specifications
- Brand: Schischek (Rotork)
- Model: EXL-IRU-1
- Warranty: One Year
- Condition: 100% New & Original
- Input Type: 1 Passive, potential-free binary ExSens sensor
- Output Type: 1 Potential-free relay contact (Safe Area)
- Supply Voltage: 24 VAC/DC
- Protection Class: ATEX certified for Zones 0, 1, 2, 20, 21, 22 (via Ex-i input)
- Installation: Module must be installed in a Safe Area
- Housing: IP20, Rail mounting according to DIN
- Features: Integrated time running relay; 2 status LEDs for switching position
4. Key Features & Benefits
- Intrinsically Safe (Ex-i) Circuit: The EXL-IRU-1 provides a galvanic separation that ensures no high-energy electrical fault can reach the hazardous zone, maintaining SIL-rated safety standards.
- Universal Compatibility: Designed to work seamlessly with the ExSens sensor series, allowing it to function as a thermostat, hygrostat, or differential pressure switch depending on the connected probe.
- Integrated Time Delay: Features an adjustable time relay, which is highly beneficial for fan belt protection or stabilizing signals from sensors in turbulent flow environments.
5. Application Scenarios
- HVAC in Hazardous Zones: Used in pharmaceutical or petrochemical labs to monitor room temperature and humidity via ExSens probes while keeping the switching logic in a safe control cabinet.
- Fan Belt Monitoring: Deployed in industrial ventilation systems to detect belt breakage or slippage using a binary speed sensor, preventing overheating in explosive gas atmospheres.
- Tank Level/Pressure Switching: Interfaces with potential-free limit switches on storage tanks to trigger high-level alarms or pump shutdowns.
6. Frequently Asked Questions (FAQ)
- Q: What is the primary function of the EXL-IRU-1?
- A: The EXL-IRU-1 is a switching amplifier that safely connects binary sensors from hazardous (Ex) areas to standard control equipment in safe areas.
- Q: Can the EXL-IRU-1 be installed directly in a Zone 1 area?
- A: No. The EXL-IRU-1 itself must be installed in a Safe Area (Non-Ex area), while its intrinsically safe input connects to sensors located in the hazardous zones.
- Q: Is the EXL-IRU-1 still in production?
- A: Note that the EXL-IRU-1 has been succeeded by newer models in some regions (such as the EXL-IR-9170). Always verify with technical support if you are performing a new installation or a like-for-like replacement.
