6ES5951-7LB21 - SIMATIC S5 power supply 951

SIMATIC S5 power supply 951 that converts the incoming AC supply into the 5 V DC rail used by the S5-115U/H system.

Documented system function

Rebuilt from individual evidence

System position

Documented characteristics

The source identifies this exact reference as a SIMATIC S5 power supply 951 for S5-115U/H without backup battery.

In the documented system, converts the incoming AC supply into the 5 V DC rail used by the S5-115U/H system.

The source documents 120/230 V AC input and 5 V DC, 3 A output.

Inferred system position: between the AC source and the S5-115U/H rack power rail.

Exact reference: 6ES5951-7LB21
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 the incoming AC supply into the 5 V DC rail used by the S5-115U/H system.
System position: Sits between the AC source and the S5-115U/H rack power rail.
Upstream / inputs: The AC installation provides the upstream electrical input.
Downstream / outputs: The power supply provides the downstream 5 V DC rail to the rack.
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 6ES5951-7LB21 as a SIMATIC S5 power supply 951 for S5-115U/H without backup battery.
Confidence: high
- www.jc-electronics.com — retrieved 2026-09-12; high confidence
The cited source describes 6ES5951-7LB21 as converts the incoming AC supply into the 5 V DC rail used by the S5-115U/H system.
Confidence: high
- www.jc-electronics.com — retrieved 2026-09-12; high confidence
The cited source documents 120/230 V AC input and 5 V DC, 3 A output.
Confidence: high
- www.jc-electronics.com — retrieved 2026-09-12; high confidence

Inferences

Inferred system position: between the AC source and the S5-115U/H rack power rail.
Confidence: medium
Rationale: The exact-reference identity and documented function establish where this component participates in the described control path.
- www.jc-electronics.com — retrieved 2026-09-12; high confidence

Unknowns

Unknown: the installed system configuration, wiring, firmware state, physical condition and replacement compatibility.
Confidence: low
Missing evidence: The individual web sources describe the product but do not establish a particular installation or unit condition.

System position diagram

The upstream system stage connects through the exact product to the downstream system stage. — The exact product participates in the system path described by the cited evidence.

View Mermaid source

flowchart LR; Upstream --> Component; Component --> Downstream

View diagram labels

Nodes: Upstream system stage; Exact product; Downstream system stage
Edges: Documented input or supply path; Documented output or control path

Next action

The captured evidence supports the documented identity and system role of 6ES5951-7LB21.

Unknown: confirm the installed rack, wiring, firmware, unit condition and replacement compatibility before use.

Request help with this reference

Provide the exact reference, machine context, and observed symptom so the next review can stay evidence-based.

Submission is unavailable until durable storage is verified.

Reference or description *Recovery mode *Country *RegionEmail *Phone

I’m unsure of the exact reference or route; keep my description for human qualification.

Add context only if useful

ManufacturerMachine or lineComponent typeUrgencyProduction impactQuantityAcceptable conditionNeed byPreferred contact

Technical context

What is known so far?

Optional updatesNotify me when the supplier price changesSubscribe to the ardkor.org newsletter

This may be safety-sensitive or emergency-related; hold it for human handling.Allow anonymous landing and source categories to be saved with this request for analytics. This is optional and separate from routing.

Recipient and data disclosure

Named recipient: Ardkor human-qualification queue (internal local preview). No partner delivery is enabled here.

Data retained for this review: reference, selected route, location, technical context, contact details, consent state, and any accepted private attachment.

Response expectation: none is promised. If external routing is enabled later, the partner name, disclosed fields, and response expectation must be shown and accepted again.

Withdrawal and deletion: use the private request controls from the receipt to withdraw further processing or request access/deletion. The request remains recorded until the relevant Ardkor systems and any recipient confirm completion.

External routing consent: I separately authorize Ardkor to use this request for human qualification in the named internal queue. No external partner is authorized by this checkbox.

Read the privacy information before sending. For corrections, access, or deletion help, use the contact page or email reference@ardkor.org; mailbox delivery and attendance have not been verified.

This routing state is separate from watch, marketing, payment, and analytics choices. If no capable service match is found, the request remains a human-qualification lead and is never presented as provider acceptance. Ardkor is not an emergency or safety service and submission does not guarantee availability, price, repair, sourcing, or response.