Ab With Banner Eyes

[rowens]

I will try to get some resistors.
yes the wye transformer is grounded.It is not a floating system

 

[rowens]

I installed the resistors this morning and replaced the eyes that the contacts had welded. so far so good. Such a simple solution to what I had thought was a complex problem.

Thanks for the help.

I never would have thought that an output would be afecting my inputs like that. I have learnt something new so I have a feeling of accomplishment for today.

 

[nettogrisen]

ground at both ends

I'm not sure, but can't gounding the cable in both ends cause a potential difference and make even more noice?

 

[rowens]

I'm not sure, but can't gounding the cable in both ends cause a potential difference and make even more noice?

I may be wrong, but it is my understanding that the ground (Green or Green/White) wire be tied to ground at both ends but the shield around the cable tied to ground on one end only.

This is the way we installed our system. Is this wrong?

 

[nettogrisen]

Maybe i wrote that wrong, sorry for adding confusion to your project.
Your ground wire should be connected at both ends, but the shield only at one end, so your grounding should be correctly installed

 

[milldrone]

After reviewing my post that was in question. I can see how I did not clearly state what I meant.

Rowens had the correct way posted in post #19

Sorry for the confusion

 

[rowens]

It is my understanding that the shield is the part that takes out the noise not the ground. That is why we ground only one end of it. The actual ground wire is inside the shield along with the conductors to act as a safety wire if something shorts out. It will take the rush of potentially dangerous current along a predetermined path back to the panel so that a fuse or breaker can open the circuit but not leave a conduit or motor to act like an electric fence waiting on someone to touch it.
That is why it is suggested to use a VFD cable instead of individual wires to a motor connected to a drive.

 

[rowens]

The resistors did not correct my problem. I lost two more photoeyes yesterday.

The Banner rep for my area came to see me and recommended a different eye. The one I was using (SMA915LVAG) was not even in the new catalog.We had several of these on the shelf-never opened.

I have a sample to try. It is a QS30VR3LP. The wiring is the same. The voltage is more universal and the paperwork does not mention about having to add anything else to the circuits.

I installed it this morming to test but the system will not restart until Monday.

 

[OkiePC]

Your original P/N is for a polarized retroreflective 90-130VAC wit h SPDT relay output.

I was confused when the discussion turned to surge suppression and output transient control.

You just unluckily got sold a bad batch of photocells...something that has never happened to me with Banner products, but has happened with some other lesser brands.

If the photocells only drive input points on a PLC card and nothing else, there is no way they should have welded the 5 amp relay contacts unless there was some intermittent short or an electrical condition that overloaded the internal relays, perhaps during checkout, and was later corrected. Isn't the input impedence of a typical PLC input card something like 10k ohms? Not nearly enough current to weld a 5amp relay closed. In that type of application, the relay photocells should last years and years. Solid state eyes will last virtually forever in that application. Most modern solid state eyes will work with most modern AC input cards without "false triggering". Avoiding that problem might be the reason a relay type eye was selected.

The new part number is also a relay type, but one of the newest Banner lines. Those little QS series eyes are fantastic in my limited experience. You will like them much better anyway.

Paul

 

[allscott]

Something is fishy here

Your original P/N is for a polarized retroreflective 90-130VAC wit h SPDT relay output.

I was confused when the discussion turned to surge suppression and output transient control.

You just unluckily got sold a bad batch of photocells...something that has never happened to me with Banner products, but has happened with some other lesser brands.

If the photocells only drive input points on a PLC card and nothing else, there is no way they should have welded the 5 amp relay contacts unless there was some intermittent short or an electrical condition that overloaded the internal relays, perhaps during checkout, and was later corrected. Isn't the input impedence of a typical PLC input card something like 10k ohms? Not nearly enough current to weld a 5amp relay closed. In that type of application, the relay photocells should last years and years. Solid state eyes will last virtually forever in that application. Most modern solid state eyes will work with most modern AC input cards without "false triggering". Avoiding that problem might be the reason a relay type eye was selected.

The new part number is also a relay type, but one of the newest Banner lines. Those little QS series eyes are fantastic in my limited experience. You will like them much better anyway.

Paul

I read this whole thread again because something just doesn't add up here. OkiePC might very well be right about a batch of bad eyes but that would be surprising because I've never had one banner product be bad out of the box let alone a whole bunch of them. Also by the OP's description is that these worked for awhile before failing??

Rowens never did tell us if he disconnected one of the eyes and measured between the hot and swith leg on the contacts with a meter to see if they were actually welded shut or whether the internal circuity was energizing the relay.

A shot in the dark but is it possible that something in the environment is actually damaging the photocell within the eye? Is there any welding going on in the vicinity? I've wrecked eyes doing that before.

Check to make sure your neutral is really neutral. Hopefully it is grounded.

Having said that I agree with Okie, the QS series are really nice. I littered the last place I worked at with them. Simply changing the eyes might make whatever the heck your problem is go away.

Let us know how you make out.