Siemens 6ES7222-5HH50-0XB0 SIMATIC S7-1200 SM 1222 16x Relay 2A PLC I/O Module

The Siemens 6ES7222-5HH50-0XB0 SM 1222 is a SIMATIC S7-1200 digital output module with 16 relay outputs rated 2 A each, switched in two groups of 8. It runs from a 24 V DC backplane supply (20.4 to 28.8 V) and dissipates 4.2 W typical. IP20-rated, it mounts directly onto the S7-1200 backplane bus for machine control I/O expansion.

Technical Specifications

Certifications & Standards

• CE
• UL
• cULus
• RCM
• KC

Selection Notes

The 5HH50 variant uses electromechanical relay contacts, not transistor outputs, so it switches both AC loads (up to 200 W lamp load) and DC loads (up to 30 W) from the same module, which the transistor SM 1222 variants cannot do on the AC side. Short-circuit protection is not built in and must be added externally, since relay contacts cannot self-limit fault current the way a solid-state output can. The 16 outputs are grouped in two banks of 8 with channel isolation via the relays themselves, and mechanical life is rated for 10 million cycles unloaded versus 100,000 cycles at rated load, which sets the maintenance interval in high-cycle applications.

Applications

Relay-level digital output expansion on S7-1200 CPUs for switching contactors, solenoid valves, indicator lamps, and other AC or DC field loads within the 2 A / 250 V AC relay rating.