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24V relay for controlling AC motor using NI 6514

I want to control 3 AC motors (230V) using NI 6514 DAQ card.

 

As far as i could get, the only possibility of controlling it (ON/ OFF it) is using a relay to enable and disable the connection.

I have searched for a 24V relay to control the motor, but not find any.

 

Kindly suggest me a relay for this rating and also let me know whether the above idea will work or not.

 

Thank you in advance.

Regards
Grugh Mike

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Message 1 of 9
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Where did you search for  a relay? In a one minute search on an electronics distributor's web site I found 12 relays with 24 VDC control and 240 VAC contacts.  None were motor start contactors, but it was not difficult to find things which met the criteria you specified.

 

You could easily drive any standard solid state relay from the 6514 and then use the output of the SSR to control any suitable motor contactor.

 

If you want a recommendation on specific relays, you need to specify at least the current or power and the number of phases in your motor.

 

Lynn

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Will the one mentioned in the link below serve the purpose ?

 

http://singapore.rs-online.com/web/p/electromechanical-relays/0351617/

 

thanks

Regards
Grugh Mike

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Grugh Mike,

 

You have not indicated how much current the motor requires.  Does the motor need to start under load? What if the motor stalls?

 

The relay you linked will probably work for very small motors but it is not designed to provide the safety features that a motor contactor would.

 

Lynn

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Most of your 24Vdc motor contactors will have small contact current rating (8-12A).  As Johnsold has said, it's hard to spec a relay not knowing anything about your motor or the conditions in which the relay will be used.  The following site offers much larger contactors but with higher coil operating voltages.  You could use a standard 24Vdc relay to drive the contactor.

 

http://www.automationdirect.com/adc/Overview/Catalog/Motor_Controls/Contactors_-z-_Starters_-z-_Over...

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Reese, (former CLAD, future CLD)

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Some call me the gangster of love.
Some people call me MoReese!
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I will get back to you once i get the motor specification.

 

Contactor serves the same purpose as relay but for a high ampere range.

Can a contactor be made open or close using a 24V DC source ?

 

Thank you in advance.

Regards
Grugh Mike

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@Grugh Mike wrote:

 

Can a contactor be made open or close using a 24V DC source ?

 

Thank you in advance.



Yes.  In fact the URL above for this 24V contactor shows different contact configurations with both NO and NC contacts.

-----------------------------------------------------------------------------------------
Reese, (former CLAD, future CLD)

Some people call me the Space Cowboy!
Some call me the gangster of love.
Some people call me MoReese!
...I'm right here baby, right here, right here, right here at home
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Dear Reese

 

But where have they mentioned in the manual that it can be triggerted using a 24 V DC source ?

 

Thank you.

Regards
Grugh Mike

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Well, the one in the initial link is a 120Vac coil.

This link:

http://www.automationdirect.com/adc/Shopping/Catalog/Motor_Controls/Fuji_Contactors_-z-_Overloads/9_...

 

Gives you a much broader choice with both AC and DC coils.  The only issue will be what your contact current needs to be.

-----------------------------------------------------------------------------------------
Reese, (former CLAD, future CLD)

Some people call me the Space Cowboy!
Some call me the gangster of love.
Some people call me MoReese!
...I'm right here baby, right here, right here, right here at home
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