Power Supply for Extended-Range S7-400 Systems
The Siemens 6ES7405-0KR02-0AA1 is a PS 405 10A R XTR power supply for SIMATIC PCS 7 and S7-400 racks, accepting 24 V DC, 48 V DC, or 60 V DC input and delivering 5 V DC at up to 10 A to the backplane bus without requiring a base load. It occupies two slots in the rack and is designed for redundant use in extended temperature environments with conformal coating. Rated input current varies by voltage: 4 A at 24 V DC, 2 A at 48 V DC, and 1.6 A at 60 V DC. Typical active power input is 95 W with a power loss of 20 W. The unit includes short-circuit protection and an optional backup battery (2x lithium AA, 3.6 V / 2.2 Ah). The extended temperature variant is rated for 0 °C to 70 °C ambient with FM approval (Ta: 0 °C to 70 °C T4). Conformal coating protects against harsh environments per ISA-S71.04 severity levels G1, G2, G3. Equipment protection class I with protective conductor connection.
Backplane Power Delivery and Slot Requirements
This supply provides up to 10 A on the 5 V DC backplane bus and 1 A on the 24 V DC backplane bus, both idling-proof. The 5 V DC rail requires no base load, simplifying configuration when the rack is partially populated. The 10 A capacity supports a fully loaded S7-400 rack with multiple CPU, I/O, and communication modules. At 50 mm wide and 290 mm tall, it occupies two adjacent slots in the S7-400 rack. Depth is 217 mm. The electrical connection uses 3x 1.5 mm² solid or stranded wire with end sleeve, accepting external diameters from 3 mm to 9 mm. Mains buffering holds the output for 20 ms on voltage failure, meeting NAMUR recommendations. Inrush current is limited to 18 A with a 20 ms half-width pulse. Overvoltage category II applies.
Certifications and Compliance
For compliance documentation, the unit is designed to meet applicable CE, UKCA, and EAC requirements as part of the SIMATIC S7-400 XTR series. The conformal coating provides protection against corrosive gases and conductive dust per ISA-S71.04 severity levels G1, G2, G3.