Selecting Siemens SITOP PSU100M 24 V DC Power Supply

David Krause2 min read
PLC HardwareSiemensTechnical Reference
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The Siemens SITOP PSU100M is a DIN-rail power supply for control systems requiring a nominal 24 V DC, 20 A output from a single-phase AC source. Its documented advantages are a 90 mm mounting width and an 85–275 V AC input range that covers 110 V AC and 230 V AC networks without manual input-range switching.

Electrical Ratings and Input Selection

Item Documented value Engineering decision
Input Single-phase, 85–275 V AC Accepts 110 V AC or 230 V AC without manual range switching.
Output voltage 24 V DC Match only loads designed for a 24 V DC supply.
Output current 20 A Keep the required load current within the stated output rating.
Mounting width 90 mm Reserve at least the documented device width on the DIN rail.

The available evidence does not state output-voltage tolerance, efficiency, inrush current, protection behavior, terminal capacity, or environmental derating. Verify those requirements in the applicable Siemens product documentation before final sizing.

DIN-Rail Space and Replacement Check

The 90 mm enclosure is stated to be 40% narrower than its predecessor. That comparison identifies a space-saving redesign, but the predecessor model is not specified. Do not infer drop-in replacement compatibility from width alone; confirm rail space, terminal arrangement, conductor routing, and clearance requirements for the exact installation.

Selection and Commissioning Procedure

  1. Confirm that the available source is single-phase AC and remains within 85–275 V AC.
  2. Confirm that every connected load accepts 24 V DC and that the combined required current does not exceed 20 A.
  3. Reserve 90 mm of DIN-rail width, then verify any additional clearance required by the applicable Siemens documentation.
  4. After installation, verify the AC source and DC output with suitable test equipment before energizing downstream loads.

No manual selection between 110 V AC and 230 V AC is required within the documented input range. The evidence does not provide wiring, torque, protection, or grounding specifications, so obtain those values before installation rather than estimating them.

Frequently Asked Questions

What is the Siemens SITOP PSU100M output rating?

The documented output is 24 V DC at 20 A.

Can the SITOP PSU100M run from both 110 V AC and 230 V AC?

Yes. Its documented single-phase input range is 85–275 V AC, allowing connection to 110 V AC or 230 V AC without manual input-range switching.

How much DIN-rail width does the SITOP PSU100M require?

The documented device width is 90 mm. Confirm any required side clearance separately because the evidence does not specify installation spacing.

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