8 relay outputs for legacy S7-300 racks
The 6ES7322-1HF01-0AA0 is an 8-channel relay output module for the SIMATIC S7-300 family, rated 24 V DC coil supply and 2 A per channel on resistive load. Each relay switches up to 2 A on inductive loads at 230 V AC or 24 V DC, making it suitable for driving contactors, solenoid valves, and small motor starters in existing S7-300 installations.
Contact ratings and mechanical endurance
Each relay is rated for 300 000 mechanical cycles at 24 V DC / 2 A, 200 000 cycles at 120 V AC, and 100 000 cycles at 230 V AC. The minimum load current for a reliable '1' signal is 5 mA — below that, the relay may not wet the contacts. Thermal continuous current per channel is 3 A, so the 2 A rated load stays within the continuous derating envelope.
Width is 40 mm, depth 120 mm, height 125 mm — occupies one S7-300 slot. Requires a 20-pin front connector (ordered separately). Isolation between channels and the backplane bus is via optocoupler, tested at 1 500 V AC. No diagnostic alarms, no wire-break or short-circuit detection — this is a basic relay module, so fault finding relies on the downstream device's own feedback.