When a safety relay or light curtain model is withdrawn, the exact part number often leads nowhere — the series may be discontinued or the code revised. The faster route is cross-referencing: capture the safety level and wiring that define the device and match them to a current alternative. This guide covers what to read and how to turn it into a replacement specification.
What defines interchangeability
A safety component is defined by the level it protects to and how it is wired. Capture these before looking for a substitute:
| Parameter | Why it matters |
|---|---|
| Safety level | PL / SIL the circuit is rated to |
| Input channels | Number of contacts or OSSD inputs |
| Output contacts | Relay or semiconductor outputs, NO/NC |
| Monitored functions | E-stop, door switch, light curtain or two-hand |
| Resolution | Light curtain beam spacing in mm |
| Protected height | The field the curtain must cover |
| Reset type | Manual or automatic restart |
A photo of the device with its code is usually enough for a specialist to propose a match.
Notes by component type
- Safety relays (PILZ PNOZ, myPNOZ): match the input channels and output contacts to the circuit.
- Light curtains (SICK C4000): match resolution, protected height and the OSSD wiring.
- Door switches and control components: match the contact logic and the guard position.
- Two-hand controls: confirm the simultaneity window and safety level.
How a cross-reference is built
- Record the original code and capture a photo of the device.
- Note the required safety level (PL/SIL).
- Match the input channels and output contacts.
- For curtains, confirm resolution and protected height.
- Wire and function-test the full safety circuit before production use.
Why use a sourcing specialist
A given safety duty is met by several manufacturers with equivalent specs — PILZ, OMRON and SICK cover safety relays and light curtains. A sourcing partner keeps multiple brands on file, checks the candidate against your code, supplies procurement documentation, and can often ship a stocked equivalent within a day or two instead of waiting on a long factory lead time.
Get a quote
If you have a safety part number — current or obsolete — send it with a photo. We return a cross-reference suggestion, price and lead time, typically within one business day.
- Browse the PILZ safety range we carry.
- Or go straight to the inquiry form.