The Siemens 6ES7405-0RA02-0AA0 is the highest-power PS 405 DC-input supply for the SIMATIC S7-400 PLC platform, delivering 20 A at 5 V DC and 1 A at 24 V DC to the backplane bus. With 168 W typical power draw from a 24/48/60 V DC source, it is designed for large-scale S7-400 configurations with extensive I/O and communication modules.

Key Features

• Accepts 24/48/60 V DC input with a wide 19.2–72 V DC tolerance range
• Delivers 20 A at 5 V DC for backplane bus and 1 A at 24 V DC for auxiliary circuits
• Occupies two slots at 50 mm wide — compact for the power capacity delivered
• 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 20 A variant powers the largest S7-400 PLC configurations — multi-rack systems with dozens of I/O modules, multiple communication processors, and high-speed signal modules in process automation plants, power stations, and large manufacturing lines where DC mains power is the available source. For AC/DC universal input at the same power level, the 6ES7407-0RA02 provides the 20 A rating with 120/230 V input flexibility.