Harsh Environment AC Prox switches

[OkiePC]

Any recommendations? The environment ranges from frozen and damp during production to hot and steamy during high pressure washdown, with some exposure to sanitizing chemicals.

We have problems with both our Mini and Micro style cordsets, and our ordinary selection of low end proximity switches.

The failure mode is usually corroded pins at the connectors and equally common is broken conductors inside the 22AWG (read cheap) cables we presently use. Those yellow PVC cords are all over the place and they are very stiff during production when the temp can get well below 0 C.

Solving the cable problem is well underway, but we may as well standardize on a superior prox switch too. Most of ours are 12mm 120VAC sensing stainless steel. There are a handful of DC prox switches too. Non of them are end shielded presently, and physical abuse is another common failure in addtion to the corrosion problem.

We try to pack them with di-electric grease, but some always seem to get missed and eventually that stuff goes away.

I am still waiting for more info on our sanitizer to determine what type of pin platings might be most compatible.

Price is always a consideration but I will insist we spend what it takes to match our environment. Our downtime is more expensive than the cost difference between what we have now and the top of the line stuff out there, but I don't want to waste money, just select the right stuff once.

So, what's the best AC prox switch on the market with a quick connector?

Thanks in advance,
Paul

 

[rsdoran]

Probably several companies but Sick http://www.sick.com/gus/en.html I know has sensors for washdown etc. environments and maybe the best prices...that may depend though.

 

[OkiePC]

Thanks Ron, checking them out now...

EDIT: We have M12 threaded and 20mm barrel diameter inductive type proxes...

 

[bwheat]

Try a "GO" switch made by Topworks. http://www.topworx.com/
I have used them in some harsh environments ranging from boiler fronts to 200 degree splashing water.

 

[panic mode]

Okie,

Just wondering why use 120VAC in moist environment?
Is this outdoors perhaps?

 

[BobB]

Omron have some new ones for wash down areas - I think most manufacturers are starting to do them now. If I remember correctly theu are described as IP69 or something similar.

I do not use them and only remember seeing them in some advertising blurb that was sent to me.

 

[BTalbot]

These are 2 wire AC rated at -12 deg.F to 248 deg.F 18mm barrel

http://www.turck-usa.com/illustrations/M4310410%20(sheet_1).pdf

the 12mm are only rated to 212 deg.F

http://www.turck-usa.com/illustrations/B1006_D87.pdf

forgot you wanted qick connect here's an 18mm don't think they have AC 12mm with QD in harsh duty, but I could be wrong.

http://www.turck-usa.com/illustrations/B1006_D105.pdf

 

[OkiePC]

Thank everybody and keep 'em coming!

I still haven't had a chance to go review all the various implementation. I think most of our problems are poor mounting and hurry up maintenance with the switches. That all results in exposing the switch faces to physical abuse.

The GO prox looks great except for it's bulk and lack of quick connectors...never saw those before, I will keep them in mind for other apps for sure.

I found a Cutler Hammer prox with a stainless face that is my 1st candidate so far.

TPC Wire and Cable is sending me a free sample to test our brittle corroded cable upgrade. They did wonders with cat track cabling and hi-flex problems at Goodyear. Don't know for sure about the temp extremes yet...

And keep the suggestions going...

Okie,

Just wondering why use 120VAC in moist environment?
Is this outdoors perhaps?

This company is very frugal and productive and they have evolved quite nicely and cheaply re-using SLC I/O cards when updating controls...that is the main reason I suspect. Most of these prox switches are SLC 1746-IA16 inputs.

I would prefer DC switches in the wet areas too, and will try to ensure that future upgrades include DC where applicable.

Thanks again, Paul

 

[George Graziano]

Does the connector have to be right at the sensor? Why not buy one with X feet long cables. That way the end is sealed. We also had fiber optic ones then the actual prox was in a safe environment.

George

 

[Steve Etter]

I saw These from Peppel-Fuchs and thought they looked really good for harsh applications. Price seemed reasonable, too.

Steve

 

[jjkisner]

I used to work in a meat packing plant we had wash downs every night. We found the using 110vac prox's worked the best 24vdc just a little water and they were done. We also found that using a quick disconnet prox didn't work well moisture and corrosion would get on the pins. We would order the prox with a long cable to reach panel and wire direct into panel. this took a little longer to wire but would last longer. Didn't really seem that one brand worked better than the other but we use alot of Turk and Banner. We started using switches from Automation Direct because of price. they seemed to work just fine.



We also packed our stuff in grease or silicon but found that it just held the water and moisture in. The best thing we found was to try to help the water get out by drilling holes in the enclosures.

As far as the cables we used a robotic cable from got from newark not sure of the part number but the cable was orange.

Hope this helps
John

 

[jdbrandt]

Old post, I know, but Brad-Woodhead has a new line of cordset/bulkhead fittings, rated IP69K, the elusive 'washdown' specification. SICK has the sensors, as previously reported.
Nobody mentioned TURCK Amphibian...are they still sold?

 

[Kev77]

Turck Proxes seem to work very well. I have some exposed to full steam streams on our refiners and no issues. They would get damaged so I got the full threaded barrels and the use the barrel to 1/2" sealtite connector that turck sells. The only hassle is not being able to see the LED.

Other then that I know Keyence has done some good dtuff for harsh areas.

Kevin

 

[BwsInNC]

We have problems with prox switches in the winter most often, from ice building up on the ends and actually contacting the moving part and gets pushed out of proximity. Fix = me going in on saturday mornings and adjusting prox switches all winter long }