Product Description:

The 3DO750.6 relay output module is part of the System 2005 Controllers series from B & R Automation. Mounted on the system backplane, it provides electromechanical isolation between the controller CPU and field loads, letting an industrial process drive solenoids, contactors, or indicator lamps directly through onboard relays. By converting low-level logic signals to mains-rated outputs, the module forms a standardized interface for step-wise actuation tasks in factory automation. This arrangement is useful where the control system must switch field-side circuits without exposing the CPU electronics to load voltage. It is intended for discrete switching duties rather than analog signal handling.

This unit offers 8 outputs arranged in two groups. Each channel carries up to 3 A continuously and may deliver 12 A starting current to inrush-prone loads, while the group limit is 8 A and the module limit is 16 A. Designers can protect each group with an 8 A time-lag fuse, and the two-group layout helps distribute loads across separate sections of the module. Nominal switching takes place at 230 VAC or 24 VDC, while the relays tolerate up to 250 VAC / 30 VDC. At lower loads, the contacts remain reliable down to 10 mA at 5 VDC, and the maximum switching frequency of 10 Hz keeps relay wear within the intended operating range.

Low contact resistance of 100 mΩ keeps conduction losses minor, and dielectric strength of 2000 VAC / 1 min between contact and coil separates the control and load circuits. Adjacent output groups are isolated up to 430 VAC, and the module has a switching capacity of 500 VA / 150 W for inductive or resistive loads. Isolation between adjacent groups also helps when separate load circuits share the same module but operate at different potentials. Typical energization takes just 4 ms, while de-energization is 6 ms typically and 8 ms maximum. These switching times support predictable response in sequential control tasks.