The Allen-Bradley 1794-OW8K module is a FLEX I/O 8-relay output module. It is designed to work with the terminal bus supply system and terminal base units inside an Allen-Bradley FLEX I/O distributed system configuration. The 1794-OW8K module is a hazardous location-approved module, and it complies with the ISA/ANSI-71.040 1985 Class G3 environment standards for noxious gas immunity. It is an 8-channel relay output module with normally-open Form A isolated electromechanical relays. This FLEX I/O module is installed on 1 of the following terminal base units, the 1794-TB3, 1794-TB3S, 1794-TB3, 1794-TBN, or the 1794-TBNF terminal base. When any of these terminal bases are used, it should have its keyswitch positioned to Position 9 to accept the 1794-OW8K module. The module is 24 Volts DC/125 mA supplied over the FlexBus module, and it is grounded with a DIN rail. All electromechanical relays are 250 Volts AC, 2 Amps, 50 to 60 Hertz rated or 5 to 30 Volts DC, 2 Amps rated.

The Allen-Bradley 1794-OW8K module can be inserted or removed under power due to its electromechanical design that does not include direct wiring. This feature saves installation and restarting time for the whole system. The module, as part of the FLEX I/O distributed I/O system, can exchange data and instructions with controllers over the DeviceNet, EtherNet, ControlNet, or Universal Remote I/O protocols. The maximum output signal delay (defined as the time from an output state change in the module’s memory to the time of the physical relay energization by the module) is 10 milliseconds. The switching frequency of the 1794-OW8K module is around 0.3 Hertz (1 operation in 3 seconds). Output fusing is strongly recommended with 3 Amps, 250 Volts AC rated slow-blow fuses.