Ground Activated Switch...

On that PET blow molding machine I'm working on, I'm looking for sources of a special type of switch. It senses a 'path to ground' at its tip.

The existing system consists of a remotely mounted sensor (they call it a 'touch switch') that connects to what they call an 'amplifier' This 'amplifier' (which looks like a contactor) provides a set of contacts that close when the sensor tip contacts a grounded surface. The remote head has a micrometer adjustment to precisely set the height of the contact tip. I'll try to snap a picture of one tomorrow to aid in the description. For the time being, here's a picture of the 'amplifier'. Sorry 'bout the lousy photo. This is just cropped out of a larger picture...
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Of course, these are no longer available, but were manufactured by Yasukawa Electric Corporation. The sensing head is a part number PNC-03, and the amplifier is a part number PNCS-01BT. A Google search for items even 'close' to these gave no results...

I'm looking for a 'modern day' replacement for these sensors. If anyone knows of something like this, or at least the correct 'term' for this type of sensor, I'd really appreciate it... :nodi:

I really doubt I can use a proximity switch in this application, as the switching differential would be too great. BTW, these are used for 'flash detection' on the mold if anyone's familiar with blow molding...

beerchug

-Eric

tanks, and tankers

I seem to remember something like this in a spec a few
years ago, related to the connection of a pipe to a
truck. 'Is is grounded' was the question.

As I recall, Crouse Hinds, or someone in that general
business, makes a 'grounded wire detector'.

Perhaps you could use something from Entrelec/SSAC/ABB...
they have a real interesting collection of electrical
properties devices in the new catalog....

Eric

I am not sure if this is what you are after, but have a look at This link

Click on technical data and have a look at the PDF file under ST Grounded Probe switch.

taken from the PDF file from the above link
The switch is actuated when a conductive path between probe terminal and ground (1M ohm or less) is established

Click to expand...

Might be what you are looking for!

Paul

P.S also posted at Ron's site! :site: &

We use a touch switch similiar to what you describe.
Its made by Telemecanique - R.B. Denison
Its called a "Tuch Switch" (no typo)
110VAC with a 'NO' switch leg or load wire out.

Here's the Picture as Promised...

Thanks. I think everyone's talking about roughly the same item. A limit switch style housing with a stud on top to connect a wire. This is basically how this switch I'm looking for operates, and I may wind up using what you guys suggest.

One problem is that I'll still have to make a 'probe'...

I was at the customer today (actually, every day this week!), so I snapped a picture of the switch in question. Notice the micrometer adjustment for the probe. The contact tip is spring-loaded as well. This switch is really IDEAL for this application, so I'm hoping to find something very similar.
[attachment]
The replacement parts section of the manual had the manufacturer's name spelled wrong. It's Yaskawa, not Yasukawa. Still no luck searching with Google though... banghead

Any more ideas???...

beerchug

-Eric

P.S. The item Paul suggested can be seen without downloading the 46MB file by clicking HERE...

Eric:

Why don't you call Yaskawa at 1-800-YASKAWA? They are in Waukegan,IL - right north of Chicago and their support group is pretty good. As a matter of fact, a close friend of mine works there so they must be very good.

On the other hand, Yaskawa seems not to care much about advertising their products on the Web or publishing much information about them (beats me why, their stuff is usually very top-notch).

Anyway, give them a call. Someone may be there even on weekend.

Ground-activated probes are being widely used as a method to verify the proper position of a terminal strip in connector insertion machines. It is simple and effective: just wire it to an NPN input of a PLC. Your unit, however, seems to be way more precise...

Thanks Ladder. The customer HAS been in contact with Yaskawa. As you can probably guess, this switch has been obsolete for some time. Yaskawa have been able to locate replacements in the past, but it seems the well has finally dried up. Yaskawa IS working on a new model to replace this unit, but supposedly it will be a few months before it will be released...

Just investigating other options for this customer. I couldn't believe Yaskawa is the ONLY company that manufaturers this type of switch, but from the responses so far, it seems they ARE...

beerchug

-Eric