PNP proximity sensor hs no output

[rixtrix1]

Been messing with a high current DC PNP proximity sensor that doesn't seem to have any output and I need some diagnostic help. The wiring in the vehicle is a little sketchy and I don't have a vehicle wiring diagram as it's an older truck with an upfitted hydraulic bucket lift. The "boom up" light isn't working and the some of the wires to the switch were pinched in half before the truck came to me. Sensor is an Eaton E57-30JS10-H with 4 wires: red is+DC in, black is NC, green is NO, and white is common according to the Eaton webpage. Green is not connected, black goes to a light to tell when the boom is out of it's rest and red is 12V positive. There are leds in the sensor base to tell when power is on( green light ) and when close proximity is encountered(red). The diodes will change color when you hold the tip of a pocket screwdriver within 10mm of the sensor, but no power out to the light. The circuit to the indicator light on the dash is good as the light works when 12V is applied directly below the switch.

It seems to me that the sensor may have been shorted out when the wiring was pinched, but at $250, I'd like to be certain before I declare it dead. Any electrical wizards out there with more experience in this than me? TIA

 

[dogdog]

Not a pro or whatchamacallit
http://www.eatoncorp.com.au/ecm/idc...aveAs=0&Rendition=Primary&dDocName=PCT_361772

wouldn't you just put a dc voltage meter on the leads and test it with a 12V hooked up to red and neg to white ? confirming that you have at least 10V-50V on the input as the specification of that sensor ?

Black is NC that means it would have power when the sensor is not triggered and would not have power when the sensor is triggered, at least that is what N.C. normally means

Green N.O. is the opposite... will have power only when the sensor is triggered?

It's a sealed unit not sure what other testing you can do on that sensor, it's all electronic parts ?

 

[MattT]

Sounds like the short nuked it. Or maybe it died a while back and the previous owner never bothered to fix it.

Either way do you really need high current for the application? If all it's powering is a lamp you could maybe use a cheaper prox. Switch to an LED indicator and you could use this.

https://www.automationdirect.com/ad...ound_harsh_duty/basic_ip69k_(30mm)/pnt6-cp-3a

 

[Mr. T]

My vote is a fried transistor. It’s either switching or it’s not. If it’s not you’ll need a new one. I’d fix the wiring before you hook it up though, if you already haven’t.

The LED indicator (usually) only means that it’s telling the transistor to change states, not that the transistor actually did.

 

[rixtrix1]

Not a pro or whatchamacallit
http://www.eatoncorp.com.au/ecm/idc...aveAs=0&Rendition=Primary&dDocName=PCT_361772

wouldn't you just put a dc voltage meter on the leads and test it with a 12V hooked up to red and neg to white ? confirming that you have at least 10V-50V on the input as the specification of that sensor ?

Black is NC that means it would have power when the sensor is not triggered and would not have power when the sensor is triggered, at least that is what N.C. normally means

Green N.O. is the opposite... will have power only when the sensor is triggered?

It's a sealed unit not sure what other testing you can do on that sensor, it's all electronic parts ?

This is the first digital sensor I've run into out of our whole fleet, rest are magnetic. I have 13.2V at the red with the key on, White goes to ground ( after repairing wires) and indicator LEDs show sensor sensitivity, but no output on black. Green was disconnected probably when installed. Thank for your input, dogdog.

Sounds like the short nuked it. Or maybe it died a while back and the previous owner never bothered to fix it.

MattT, my thought, too. This came from another one of our locations in AZ as a spare to be re-issued in the PHX metro area.

Either way do you really need high current for the application? If all it's powering is a lamp you could maybe use a cheaper prox. Switch to an LED indicator and you could use this.

Since this is an aerial lift, it's federally regulated and parts cannot be substituted without manufacturer approval!

https://www.automationdirect.com/ad...ound_harsh_duty/basic_ip69k_(30mm)/pnt6-cp-3a

My vote is a fried transistor. It’s either switching or it’s not. If it’s not you’ll need a new one. I’d fix the wiring before you hook it up though, if you already haven’t.

The LED indicator (usually) only means that it’s telling the transistor to change states, not that the transistor actually did.

Thanks, Mr. T. As with most companies, budget is a concern especially with equipment as repair is a hard money situation, so I want to make sure the diagnosis is correct, before getting such an expensive part.
Nothing is shown in the factory wiring diagram as the led portion is probably proprietary.

I have my parts guy looking for a replacement locally The manufacturer has been absorbed by another and parts delivery is usually 3-6 weeks and no returns on electrical parts from them.

 

[MattT]

I have my parts guy looking for a replacement locally The manufacturer has been absorbed by another and parts delivery is usually 3-6 weeks and no returns on electrical parts from them.

Have your parts guy check local electrical supply houses. One of them should be a full line Eaton distributor. Probably take a week to a week and a half to get one on a stock delivery or next day if you want to throw money at it. Or you might get lucky and they'll have them on the shelf.

 

[dogdog]

This is the first digital sensor I've run into out of our whole fleet, rest are magnetic. I have 13.2V at the red with the key on, White goes to ground ( after repairing wires) and indicator LEDs show sensor sensitivity, but no output on black. Green was disconnected probably when installed. Thank for your input, dogdog.
...........

but here is the thing though....

Green is disconnected but it is listed as Normally Open, it usually means when the sensor is active, it would show 12V (or supply voltage) between the White wire (which is the Negative), That is if you are looking for it to lit something when sensor is active.... even though it is not connected to anything... it would still show voltage at that lead if sensor is triggered.... and would not show voltage if it is not...

the Black is N.C. , normally closed, means when sensor is not triggered, it would show supply voltage between the White wire (which is the Negative)... and would NOT show voltage when the sensor is triggered... and shows voltage when sensor is NOT triggered.


means black is NOT suppose to show voltage when the sensor is activated.



That is voltage between the white wire and black or white wire and green....



Just saying... just making sure, sometimes my brain is not on the same page....

if you tested that and didn't show any voltage in those scenario, then I would be looking to get it replaced.... not sure if maintenance on these things allows you to open it and mess with it... it is consider some sort of safety devices... last thing you wanted is talking to those people about something ....why you repair it..

 

[American Locomotive]

My advice: find out what else that proximity sensor connects to. If it is literally just foe that light, replace the indicator with an LED and get the $25 automation direct prox.

 

[MattT]

My advice: find out what else that proximity sensor connects to. If it is literally just foe that light, replace the indicator with an LED and get the $25 automation direct prox.

The OP has ruled that out as an option. Formatting buried it in a quoted post so don't feel bad about missing it. I had to look twice to notice it.

Since this is an aerial lift, it's federally regulated and parts cannot be substituted without manufacturer approval!

 

[rixtrix1]

dogdog, I did show some voltage in the scenarios, you described, but it was way below battery voltage and didn't have enough current to light the bulb. The bulb only lights, in testing, with battery voltage applied to the black wire. Perhaps the reason for using a high current (2-8a)sensor. Thanks again for your input. If there was a wiring diagram for the upfitted truck, testing would be easier to figure out, but it seems every employee at every upfitter does things differently than the others, so no 2 trucks are alike. Really love it when they wire the whole truck body with the same color wire!

Sent from my SM-J320V using Tapatalk

 

[dogdog]

I think the only other things you can do is verify this with a known load, sort of like a bench test (your own light bulb), away from truck's wiring... just in case something else is drawing more current that cause the voltage drops...... or put an amp meter on highest setting and verify the current draw maybe?... at least you have covered A-Z needed for this sensor and not get rimmed for not doing due diligent...etc etc etc..... sometimes if it is broke , you just have to replace it....if you wanted it back in service....

I have a wifi amp that have switching transistor blown, but that thing would heat up and eventually refuse to conduct... maybe look for sign of over heating at that sensor body? for these type of transistor circuits...

 

[American Locomotive]

The OP has ruled that out as an option. Formatting buried it in a quoted post so don't feel bad about missing it. I had to look twice to notice it.

I missed it because of thef formatting.

Still, if money is tight and the only thing this proximity sensor does is turn on an indicator bulb...would anyone know? Like what are you supposed to do if the part is NLA and the aerial lift company is out business? Throw the whole lift out? I'm not trying to advocate doing anything illegal, especially since my gut feeling is that the prox is likely used for something else as well.

 

[mm08822]

If the lift is regulated where no unapproved/authorized changes are permitted, you have your answer. Buy the same part #’d item. Google the part # and you will find plenty of sources. You are lucky the standard OEM part was not re-branded.

If the lift is needed, $250 for a part is nothing. Think of the rental costs otherwise or even just the loss of productivity.

Take pics, replace the part and log that the replacement was installed as original and operates the same. If it is not documented, it didn’t happen.

 

[nsula_country]

EZ Automation

https://www.ezautomation.net/ezvizprox/ezvizprox_menu.htm

https://www.ezautomation.net/ezvizprox/EZProx-specifications.pdf

I have actually used these at work before.

Just matchup barrel size, shielded or unshielded and output type. (30mm, NPN)

What bothers me is why it needs a 3.5A prox? The 30mm EZ Prox is 400mA. Is a valve coil going through this?

EDIT. The Eaton switch is designed for truck applications. Galco has it for $160.

CT

 

[rixtrix1]

Got a replacement and it doesn't need to be a high current model, according to company engineers. It was what was available when unit was manufactured, even if it was spec'd for a higher draw.

Thanks for everyone's insights!