6ES5955-3NC42 - SIMATIC S5 PS955 power supply 18 A DC
SIMATIC S5 PS955 power supply 18 A DC that converts 24 V DC input into regulated S5 rack supply rails.
Documented system function
Rebuilt from individual evidence
System position
Documented characteristics
The source identifies this exact reference as a SIMATIC S5 PS 955 power supply module for S5-135U/-155U and EU 183U/185U.
In the documented system, converts 24 V DC input into regulated S5 rack supply rails.
The source documents 24 V DC input and 5 V DC/18 A output.
Inferred system position: between the external 24 V DC source and the S5-135U/155U rack rails.
- Exact reference
- 6ES5955-3NC42
- Category
- PLC / CPU
- Evidence checked
- 2026-09-12
System role
This section explains what the product does and where it acts in the surrounding system.
- Function
- converts 24 V DC input into regulated S5 rack supply rails.
- System position
- Sits between the external 24 V DC source and the S5-135U/155U rack rails.
- Upstream / inputs
- The external 24 V DC installation provides the upstream power input.
- Downstream / outputs
- The PS955 provides regulated DC rails to downstream S5 modules.
- Limitations
- Unknown: the installed system configuration, wiring, firmware state, physical condition and replacement compatibility.
Evidence ledger
Facts, inferences, and unknowns are kept separate.
Facts
The cited source identifies 6ES5955-3NC42 as a SIMATIC S5 PS 955 power supply module for S5-135U/-155U and EU 183U/185U.
- www.classicautomation.com — retrieved 2026-09-12; high confidence
- cache.industry.siemens.com — retrieved 2026-09-12; high confidence
The cited source describes 6ES5955-3NC42 as converts 24 V DC input into regulated S5 rack supply rails.
- www.classicautomation.com — retrieved 2026-09-12; high confidence
- cache.industry.siemens.com — retrieved 2026-09-12; high confidence
The cited source documents 24 V DC input and 5 V DC/18 A output.
- www.classicautomation.com — retrieved 2026-09-12; high confidence
- cache.industry.siemens.com — retrieved 2026-09-12; high confidence
Inferences
Inferred system position: between the external 24 V DC source and the S5-135U/155U rack rails.
- www.classicautomation.com — retrieved 2026-09-12; high confidence
- cache.industry.siemens.com — retrieved 2026-09-12; high confidence
Unknowns
Unknown: the installed system configuration, wiring, firmware state, physical condition and replacement compatibility.
System position diagram
View Mermaid source
flowchart LR; Upstream --> Component; Component --> DownstreamView diagram labels
- Nodes
- Upstream system stage; Exact product; Downstream system stage
- Edges
- Documented input or supply path; Documented output or control path
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