What this power supply does on the S7-1500 backplane
The 6ES7505-0RB00-0AB0 is the SIMATIC S7-1500 system power supply with buffer functionality, delivering 60 W to the backplane bus and permitting the CPU to retain RAM data retentively during a mains failure. It accepts three DC input voltages: 24 V DC (rated 3 A), 48 V DC (rated 1.5 A), or 60 V DC (rated 1.2 A), with a static permissible range of 19.2 V to 72 V DC and dynamic range extending to 18.5 V–75.5 V DC. Inrush current ≤ 8 A for ≤ 1 s. It includes reverse polarity protection, short-circuit protection, and isolation tested at 2 500 V DC. Power loss 12 W. Hold-up time is 20 ms, enough to bridge brief line dips. The unit is IP20 rated, protection class I with protective conductor. It integrates with TIA Portal from V14 SP1 onward, firmware version V1.0.0, HW functional status E01.