230VAC Contactor (24VDC Coil) wiring with 24VDC Proximity Sensor

[sham96]

Hello Everyone!

I am trying to figure out how to connect a 24VDC NPN Proximity Sensor to a 230VAC contactor with 24VDC coil. I need the contactor to turn ON/OFF with the sensor signal. I have followed the below wiring diagram but my attempts have been unsuccessful (The contactor does not switch ON/OFF with the sensor signal). Should i use a relay to amplify the sensor signal? Both sensor and contactor are in perfectly good working condition. Any help will be greatly appreciated!

 

[RedSnake]

What is the brand and ordering number of the proximity switch?

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

 

[che12345]

Dear Mr. sham96 (Automotive)(OP)30 Oct 21 04:01
"..1).I am trying to figure out how to connect a 24VDC NPN Proximity Sensor to a 230VAC contactor with 24VDC coil. I need the contactor to turn ON/OFF with the sensor signal. I have followed the below wiring diagram but my attempts have been unsuccessful (The contactor does not switch ON/OFF with the sensor signal).2) Should i use a relay to amplify the sensor signal? ..."
1. Check that your proximity sensor is a NPN type. The circuit you had wired is correct.
2. Check the sensor output current rating, could be around 200mA max? This output may be? is too low to switch on a "contactor". Attention: a small "AC switching contactor with 24Vdc coil may? required say >4-5W to pull-in. Yes, use a (relay) to [amplify the sensor signal] may? work.
3. Attention: chose a (24Vdc coil relay) with [coil pull-in current is =< than the output max of the sensor].
4. Please report back the result or if you are still facing difficulties. We all will learn some thing on how the problem is resolved.
Che Kuan Yau (Singapore)

 

[RedSnake]

If the contactor is a LCD..BL
The coil have a built-in interference protection bi-directional nail-limiting diode.
LAD4TBDL.

So your diagram looks like this, OBS since I do not know what proximity switch you are using this diagram is for a Omron E2A-@-@-C1.
If your proximity switch has a indication diod that can also make a difference for the function.

If it is mounted on the side you can take it out and try without.
I am not quite sure how this impacts the function of the proximity switch.

We normally never use NPN products and we never build things where we use the neutral for turning things ON/OFF.
Mostly switches are connected to inputs or relays.
And the contactors are on and off by outputs or the relay.

Best Regards A

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

 

[RedSnake]

2. Check the sensor output current rating, could be around 200mA max? This output may be? is too low to switch on a "contactor". Attention: a small "AC switching contactor with 24Vdc coil may? required say >4-5W to pull-in. Yes, use a (relay) to [amplify the sensor signal] may? work.

In the picture provided it says it is a low consumption coil.

And my assumption from the picture is that it is a LCD..BL and then it has a 2,4W coil that needs 100mA.

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

 

[che12345]

Dear Mr. sham96 (Automotive)(OP)30 Oct 21 04:01
1.Further to my post dated 30 Oct 21 09:00; I strongly suggest to try out by using a low cost (24Vdc "relay") with [coil pull-in current is =< than the output max. of the sensor].
2. There are many different brands of [24Vdc relay] rated 8/10A , 8-pin DPDT/SPST etc on the market. Their basic construction are the same, with a very small (iron-core) having a [hinged armature]. Their typical coil data: Vn= 24Vdc , min. operation voltage 0.85 Vn. Coil resistance 662 Ohm, rated current 36.3mA, power consumption 0.9W approx.
3. Your sensor output should be able to drive this "relay". The number of N.O/N.C and their voltage, current rating would depend on the load. If this relay works, then you may use it as an (interface relay) to operate a [much larger "contactor"], to suit the load.
4. Please report back the result or if you are still facing difficulties. We all will learn some thing on how the problem is resolved.
Che Kuan Yau (Singapore)

 

[LionelHutz]

I wouldn't connect those directly, I would use a small control relay with a low coil consumption.

 

[che12345]

Dear Mr.sham96
@ LionelHutz (Electrical)1 Nov 21 12:21
"...I wouldn't connect those directly, I would use a small control relay with a low coil consumption.".
My suggestion is to try it out with a low cost "relay" typical coil data: Vn= 24Vdc , min. operation voltage 0.85 Vn. Coil resistance 662 Ohm, rated current 36.3mA, power consumption 0.9W approx. The sensor output should be able to drive this "relay". Are you doubtful that the sensor is ABLE to drive a 36.3mA, 0.9W "relay" directly?. If that is the case, please advise a better "small control relay" that is "significantly" lower than 0.9W and yet has power contacts sufficient to switch a larger "contactor".
Che Kuan Yau (Singapore)