The Siemens 6ES7405-0DA02-0AA0 is the entry-level PS 405 DC-input power supply for the SIMATIC S7-400 PLC platform, delivering regulated 5 V DC and 24 V DC to the backplane bus for CPU, communication module, and I/O module operation.

Key Features

• Accepts 24/48/60 V DC input with a wide 19.2–72 V DC tolerance range
• Delivers 4 A at 5 V DC for backplane bus and 0.5 A at 24 V DC for auxiliary circuits
• Occupies a single slot at just 25 mm wide — maximizes rack space for I/O modules
• 20 ms mains buffering bridges short power interruptions without CPU reset
• Galvanic isolation between primary and secondary sides for signal integrity
• Short-circuit-proof and idling-proof 24 V output
• Supports optional backup battery (1× or 2× lithium AA, 3.6 V) for CPU data retention
• ATEX, IECEx, CE, UL, and UKCA certified for global deployment

Technical Data

Applications

The PS 405 is purpose-built for S7-400 PLC installations where DC mains power is available — typical in battery-backed industrial systems, DC-powered control cabinets, and transportation applications. The 4 A variant is sized for small to medium I/O configurations where minimizing rack space is a priority. For larger configurations, the 10 A (6ES7405-0KA02) and 20 A (6ES7405-0RA02) variants provide additional backplane power.