8 relay outputs rated 5 A — what that means for your S7-300 rack
The 6ES7322-5HF00-0AB0 is an S7-300 SM 322 digital output module with 8 relay outputs, each rated 5 A for both resistive and inductive loads at 24 V DC and 230 V AC. The relay contacts are rated for 100,000 mechanical cycles at full load, which sets the service life expectation for solenoid or contactor switching duty. The module accepts both 24 V DC and 230 V AC on the same output channels — the permissible range spans 24 V DC to 120 V DC, and 24 V AC to 230 V AC. This mixed-voltage capability lets a single module drive a 24 V DC pilot light on one channel and a 230 V AC contactor coil on the next, simplifying panel wiring when the control voltage and the load voltage differ.
Sourcing reality — EOL hot, sourced to order
No official Siemens successor order code is on record for this module. If a form-fit-function replacement is needed, the closest candidate in the S7-300 relay output family is the 6ES7322-5HF00-0AB1 — verify the pinout and firmware compatibility against your specific rack configuration before substituting.
Panel fit and wiring constraints
The module occupies a single S7-300 slot at 40 mm wide, 125 mm tall, 120 mm deep — standard form factor for the SM 322 series. It requires a 40-pin front connector (ordered separately) for field wiring. The 40-pin connector carries all eight output channels plus the shared commons, so the wiring density is moderate; plan for at least 0.5 A per channel backplane current draw (100 mA from 5 V DC backplane bus, 160 mA from 24 V DC L+ supply). Short-circuit protection is not provided on the module — it must be supplied externally per channel or per group. The relay outputs are isolated between channels in groups of one, with 1500 V AC isolation tested between the channels and the backplane. Diagnostic alarms are parameterizable and report group errors via the red SF LED on the front panel.