1proximity switch not turning off

[fubrain]

Hello,
One of my proximity switches wont turn off the other is fine is there a easy way to check the cable or the switch it self
THANKYOU!

[richards]

Get a bolt (1/2-inch diameter works great) and move it very close to the switch. The switch should light up. If it doesn't, then either the switch is defective or one of the wires is broken/disconnected. (I'm assuming that both the good switch and the non-working switch are wired to the same points on the control board.) If the bolt test works, then most likely, you'll have to re-align the sensor to your target or decrease the gap between the sensor and the target.

My prox. switches are basically factory sealed with heat-shrink tubing at all possible test points. I don't have any schematics for the switch, but I would think that you have one wire connected to VCC (+5vdc probably), one wire connected to ground, and a third wire acting as the output from the switch that probably floats near VCC until the switch is active, then it should be pulled low to almost 0VDC.

If the bolt test doesn't work, I would carefully check all connections from both prox. switches inside the control box. Make sure that none of the wires has come lose. If they're all firmly fastened, you'll have to decide if you want to slice into the cable near the switch to check continuity.

[alabama_davo]

I had a problem with the switch being too far away from the bolt and it would overrun etc. adjust the bolt closer and try it again...

[fubrain]

Thanks Guys,
The problem is that the light is on all the time No matter what i do any more ideas would be great! thankyou fubrain

[fleinbach]

Ross,

Did do you just install them or were they working for a while before the light stayed on?

[paco]

Hi Ross!

Have you checked it's circuit unpluged for continuity/non-continuity?... maybe it's not the switch... if it test good, check the rest of the wiring/connection...

Since you did'nt specified, I wonder, like Frank, if it was working properly "before"...

[richards]

Ross,
Are you talking about the light on the sensor or the light on the SB display? If one is on, then the other should be on also. Of course, if they're both on, the machine should think that it's hit a limit and stop.

If wired correctly and functioning correctly, the sensor should only light up when it is very close to metal (1.8mm or about 0.007 inch).

[beacon14]

1.8mm = .07" (not .007")

[richards]

David,
Thanks for catching the error. I'll send my abacus out for service first thing in the morning.

[fubrain]

Great help!,
Both proximity switches were working properly for about 1 1/2 years. THe light on 1 proximity switch wont shut off so i guess its on all the time? The other is fine. I dont want to buy a new one if not needed
Thankyou again