In this guide
Counterfeit and mislabelled automation parts exist, particularly for popular, expensive, hard-to-find modules. A fake controller can behave oddly, fail early, or in a safety circuit fail dangerously. The sensible response is to buy carefully, not to be paranoid.
Where the risk comes from
The risk rises when a part is discontinued, in short supply or priced well below the market. Anonymous online listings and unsolicited offers carry more risk than an established supplier with traceable sourcing.
Warning signs
- A price far below what other suppliers quote
- No clear information about where the part came from
- Packaging or labels that look unusual: poor print, inconsistent fonts, missing markings
- Serial numbers that are missing, duplicated or do not verify with the manufacturer
- A part that looks reworked, with scratches, mismatched screws or a different weight to a known good unit
- Reluctance to provide invoices, a warranty or a returns policy
Questions to ask a supplier
- Where do you source this part from?
- Is it new, surplus or refurbished? Say so in writing on the quote
- What warranty and returns terms apply?
- Can the serial number be verified?
- Will you provide a proper invoice and documentation?
- Who do I speak to if it does not work?
Before it goes in the machine
- Compare the label, finish and markings against a known good unit
- Check firmware or version information against what the system needs
- Bench-test where practical before installing, especially for safety parts
- Keep the packaging and paperwork
Safety-related parts
For safety relays, safety controllers and safety-rated sensors, buy only from sources you can trust fully and keep the paperwork. A part that merely works on the bench is not the same as a part certified for its safety function.
How we approach it
When you request a quote from us, ask about the source, condition and terms of the part, and put the same questions to any other supplier you use.