Hello,

I need to find a replacement for this retro reflective photo sensor.

The sensor controls the height of a tray - when the paper stack gets too high, it lowers the tray by a defined amount.

It has a reflector on the other side approximately 65 cm away. It's AC powered as you can see in the label. I think it's basically an AC relay that switches on/off the motor contactor for the tray?

Is there a drop in replacement for this? I cannot find even a used one online and some similar-age, used ones are being scalped for over 300 euro from what I see on ebay.

I do not usually have to deal with equipment/sensors like this, also I am not a service/industrial engineer, so my apologies in advance if this is the wrong forum for this type of question.

 

These are the extra rugged types of Sick and 300 euro's is quite a normal price for them.
It is indeed AC powered and most often they switch with a switchover relay contact, but it can also be there it is acting as a NPN/PNP proximity sensor.
But my take with most Sicks is that they most often have a relay contact. You should be able to verify this using the schematic of the control cabinet where this Sick sensor is connected to.

I also repaired many of those by just using a hammer and give it some gentle ticks while the internal relay under power. Are you also 100% sure that the mirror is aligned well. It sends a beam to a reflector and the beam is detected by the Sick. Often these sensors get hit by something causing a misalignment, then you have a quick fix.

You can also replace the internal relay, a few guys in one of our factories were able to do that.

Anyway, these extra rugged Sick relays are still available in many types and configurations. Contact your local Sick supplier for advice and help:
https://www.sick.com/nl/en/catalog/...oelectric-sensors/w26/c/g433551?tab=selection

 

Hi,
Yes — it looks like a simple retro‑reflective photo sensor used to detect the paper stack height. These sensors typically act as a switch input to your controller or relay that drives the tray motor.

A direct drop‑in replacement might be hard to find for older part numbers, but you can replace it with any modern retro‑reflective (with reflector) photoelectric sensor that meets these criteria:
-AC‑powered (mains supply) or a compatible supply voltage
-Retro‑reflective type with a reflector
-Sensing range ≥ 65 cm
-Output type compatible with your controller/contactor (e.g., relay output or PNP/NPN plus interface relays if needed)

Common brands like Omron, Keyence, Pepperl+Fuchs, Sick, Panasonic make suitable replacements. Just match the supply voltage, sensing distance, and output type — you don’t need the exact original model.
If your control logic expects a simple ON/OFF signal, you can even use a modern DC photo sensor with an interface relay to mimic the original behavior.

 

Hey guys, thanks for all the replies.

My best guess is that the IR source on that thing has burned out... it has a little LED indicator on the top of the unit that is ON when there is no obstruction and is OFF when it detects one. And it behaves the same way as if there was a high enough paper stack - it continuously commands the motor to move the tray downwards when set to AUTO. I tried playing with the reflective mirror but nothing changed.

The annoying thing is that you can't command the tray to lift upwards (since it thinks that there's lots of paper on it and it can't go higher) and you have to open the electronics panel and override it using the motor contactor.

Also there's no wiring diagram anywhere on the machine, so I am SOL on that front. There's no need for rugged sensor or anything fancy like that, it's a simple manually operated 50 year old paper collator and this sensor just operates the paper tray which poses no risk to the operator, so even if something did go wrong with it, the worst that would happen is mild frustration...

The local industrial supply shop in my area doesn't really specialize in sensors like that, so no luck there either. I was wondering if a cheap OMRON E3JK-R4M1 knock-off that goes around for 15-20 euro would work.

There's only 5 wires on it right? L+N for powering the sensor itself and 3 contacts for the relay (NC, COM, NO) if I'm not mistaken?

My biggest worry really is that because there's no wiring diagram anywhere to be found in the cabinet and the color coding on the wires is completely random is not to mess something up and fry the obscure control board that this machine uses...