How to buy used PLC parts

Identify the complete replacement part

Copy every letter, digit, hyphen and suffix from the nameplate. Record any hardware series or firmware shown separately. A similar model number or matching housing is not enough to establish compatibility.

• CPU: check the installed project, program and data memory, supported I/O and network requirements.
• I/O: match input or output direction, signal range, relay or transistor type, polarity, isolation and terminal arrangement.
• HMI: check the full terminal version, project, display size, panel cutout and controller connection.
• Servo and rack parts: include the connected motor or controller, supply, cables, backplanes and accessories.

Use the manufacturer references linked from product specifications to check the exact configuration. Retain the machine project and parameter backup, and have any proposed substitution checked against the installation.

Choose an acceptable condition

Tell us which conditions are acceptable for your requirement. These are request options; a product page does not mean every condition is available.

New

Unused part in original or supplier-confirmed new condition. Packaging details are confirmed on the quote.

Never Used

Unused surplus part that may have open, missing, or aged packaging. Photos are shared when available.

Refurbished

Previously used part inspected or repaired by a supplier. Test scope and warranty terms must be stated on the quote.

Used

Pulled or secondary-market unit with visible use. Power-on or function test notes are shared when available.

For Parts / Repair

Not sold as working unless explicitly stated. Suitable only for repair, parts recovery, or evaluation.

Obsolete or discontinued describes the model's lifecycle. It does not establish the physical condition or test status of a particular unit. See the condition definitions when comparing offers.

Review photos and test information

Ask for actual unit and nameplate photos when available. Check the label, connectors, terminals and visible wear. For an HMI, include the display and touch-panel condition; for a module, confirm the terminal block or mating connector offered.

A catalog image identifies the product appearance. It does not show the condition or contents of the offered unit. A page with no image can still identify a model; request available photos with the quote.

Read the test scope. A power-on result describes a different check from communication, I/O or application testing. Specify which checks you require and confirm what evidence is available for the unit. Photos alone do not establish functional performance.

For operator terminals, use the used HMI panels buying guide to review communication, panel cutout, application backup and screen checks.

For cabinet power, compare input ranges, current derating, UPS storage and protection modules in the Siemens SITOP power supply buying guide.

Compare the written quote

Compare the complete offer: exact model and version, quantity, condition, included accessories, price, available test information, freight and dispatch timing. If the page has no price, send an enquiry for your required condition and quantity.

State the destination and the date the machine needs the part. Dispatch timing and arrival timing are different; the shipping arrangement and delivery estimate are confirmed for the quote.

Check the applicable warranty or DOA window, exclusions and evidence requirements before payment. Support depends on the quoted unit and test scope. For return handling, follow the written approval process in the existing policy.

Prepare your parts enquiry

Include the following details in the RFQ. Leave a requirement open when it is unknown and explain what information you can provide from the machine.

• Brand and complete model number; quantity for each model.
• Required hardware series, firmware, suffix and connected equipment.
• Acceptable condition and required accessories or terminal parts.
• Destination country, required date and any urgent downtime requirement.
• Required photos, test scope and other quote requirements.

Response hours: Mon–Sat, replies within 12–24h. Contact details and sourcing support are available on the contact page.