The VIPER SEU-31-i Safety Relay Expansion Module (Part Number: 280007) manufactured by IDEM Safety Switches Ltd (United Kingdom) is an advanced contact multiplication unit with enhanced diagnostics, designed to expand the output capacity of master safety relays. Directly connected to any VIPER SCR base safety relay (such as SCR-21-i, SCR-31-i, SCR-73-i, SCR-31P-i, SCR-31-42TD-i), it allows engineers to de-energize multiple high-power actuators simultaneously while upholding the highest functional safety ratings up to Category 4 / PLe (ISO 13849-1) and SIL 3 (IEC 62061).

PRODUCT OVERVIEW & SPECIFICATIONS (PART NO: 280007):
- Part Number: 280007
- Model: VIPER SEU-31-i
- Termination: Fixed Screw Terminals.
- Contact Configuration: 3 Normally Open (N/O) safety output circuits and 1 Normally Closed (N/C) feedback monitoring circuit.

KEY HIGHLIGHTS:
- Seamless Cascading Capability: Multiple SEU-31-i expansion modules can be daisy-chained to a single SCR master safety relay to fulfill complex multi-zone plant shutdown requirements.
- External Device Monitoring (EDM): The N/C monitoring circuit integrates directly into the feedback loop of the master relay, ensuring immediate detection of welded contacts before permitting machine restart.
- Front-Panel LED Diagnostics: Features clear visual LED status indicators for Power and individual relay channel health (K1, K2).
- Space-Saving 22.5 mm Footprint: Ultra-slim DIN-rail enclosure engineered for high-density control cabinets, snapping directly onto standard 35 mm DIN rails.

• Manufacturer: IDEM Safety Switches Ltd
• Origin: United Kingdom
• Part Number: 280007
• Model: VIPER SEU-31-i
• Device Category: Safety Relay Output Expansion Module
• Master Relay Compatibility: All IDEM VIPER SCR Series Base Relays (SCR-21-i, SCR-31-i, SCR-73-i, SCR-31P-i, SCR-31-42TD-i)
• Operating Supply Voltage: 24V AC/DC (+/- 10%, 50/60 Hz)
• Power Consumption: Approx. 1.8 W / 2 VA
• Contact Configuration:
  - Safety Contacts: 3 x N/O (Normally Open - gold-plated silver alloy, force-guided)
  - Auxiliary Feedback Contact: 1 x N/C (Normally Closed)
• Switching Capacity:
  - AC Voltage / Current: 250V AC / 6A (Max. 1500 VA)
  - DC Voltage / Current: 24V DC / 6A (Max. 144 W)
• Response Time (Release): Less than 20 ms
• Achievable Safety Ratings (In combination with master SCR relay):
  - ISO 13849-1: Category 4, PLe
  - IEC 62061: SIL CL 3
  - MTTFd: > 100 years
  - Diagnostic Coverage (DC): 99% (High)
• Termination: Fixed Screw Terminals (Conductor size: 0.2 – 2.5 mm²)
• Mounting Style: Standard 35 mm DIN Rail (EN 60715)
• Dimensions: Width 22.5 mm x Height 99 mm x Depth 114 mm
• Protection Degree: IP40 (Enclosure housing) / IP20 (Terminal blocks)
• Ambient Operating Temperature: -20°C to +55°C
• Typical Applications: Expanding safety output circuits to isolate multiple motor starters, variable frequency drives (VFDs), safety servo drives, and pneumatic/hydraulic dump valves on presses, packaging machines, and automated robotic assembly lines.