Allen-Bradley 1794-OW8 FLEX I/O 8 Relay Output Module

General Specifications

• Outputs per Module:
  • 1 group of 8 Form A (normally open) isolated electromechanical relays.
• Module Location:
  • Mounts on the following Terminal Base Units:
    • 1794-TB2, 1794-TB3, 1794-TB3S, 1794-TBN, 1794-TBNF.
  • For 1794-TBNF, use 3.0 A, 250V AC slow-blow fuses (Littelfuse part number 239003).
• Off-State Leakage Current:
  • Maximum 1.0 mA at 240V AC through the snubber circuit.
• Minimum Contact Load:
  • 100 µA at 100 mV DC.
• Flexbus Current:
  • 5V DC, 35 mA.

Power and Voltage Specifications

• Supply Voltage:
  • 24V DC, 125 mA (1794-OW8).
  • 19.2…31.2V DC, 125 mA (1794-OW8XT).
• Relay Contact Ratings:
  • 250V AC, 2 A, Resistive, 50/60 Hz.
  • 120/240V AC, Pilot Duty, 50/60 Hz:
    • 1800V A Make, 180V A Break.
  • 5…30V DC, 2 A, Resistive.
  • Pilot Duty Rating: R150, 28V A (not to exceed 1 A below 28V DC).

Performance Specifications

• Output Signal Delay:
  • OFF to ON: Max 10 ms.
  • ON to OFF: Max 10 ms.
• Initial Contact Resistance:
  • Max 30 mΩ.
• Switching Frequency:
  • Max 1 operation every 3 seconds (0.3 Hz at rated load).
• Bounce Time:
  • Mean 1.2 ms.
• Expected Contact Life:
  • Minimum 100,000 operations at rated loads.

Thermal and Power Characteristics

• Thermal Dissipation:
  • Max 18.8 BTU/hr.
• Power Dissipation:
  • Max 5.5 W.

Isolation and Safety

• Isolation Voltage:
  • 250V (continuous), Basic Insulation between:
    • Relay to relay, relay to backplane, and relay to power.
  • 50V (continuous), Basic Insulation between power and backplane.
  • Type-tested isolation:
    • 1500V AC for 60 s (relay-to-relay).
    • 3250V DC for 60 s (relay-to-backplane and relay-to-power).
    • 720V DC for 60 s (power-to-backplane).
• Fusing:
  • Recommended 3.0 A, 250V AC slow-blow fuses (Littelfuse part number 239003).

Indicators and Physical Characteristics

• Status Indicators:
  • 8 yellow LED indicators for output status.
• Keyswitch Position:
  • 9.
• Terminal Screw Torque:
  • Determined by the installed terminal base.
• Dimensions (HxWxD):
  • Approx 94 x 94 x 69 mm (3.7 x 3.7 x 2.7 in.), with module installed.
• Enclosure:
  • None (open-style).
• Wiring Category:
  • Refer to Industrial Automation Wiring and Grounding Guidelines for routing conductor details.