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B and C Starter relay

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recapen(at)earthlink.net
Guest

Posted: Mon Mar 02, 2009 8:38 am Post subject: B and C Starter relay

Does anyone know how much current the B & C S702-1 starter relay draws at the "S" terminal when active?



I know that the two large terminals will carry what I need - I'm trying to determine if the 6A (at) 12VDC capable switch that I would like to use is sufficient or whether I need a relay to drive the starter relay.



Thanks,



Ralph Capen

frank.hinde(at)hp.com
Guest

Posted: Mon Mar 02, 2009 8:57 am Post subject: B and C Starter relay

I don't know for sure but I would not go with an intermediate relay in any case as you are adding parts count..I.e something else that can leave you stranded far away from home if it goes wrong.



If you need to (and I doubt that you will because this is a short term load) I would get a bigger switch.



Frank 



--

dale.r(at)cox.net
Guest

Posted: Mon Mar 02, 2009 9:43 am Post subject: B and C Starter relay

Ralph,



   Do you have access to an ohm meter (or DMM)? 

Measure the resistance of the relay coil (S-term to GND)

and divide 12v by the value you get and you will have

the amperes it draws.



Dale R.



Ralph E. Capen wrote:

 	  Quote: 	
		   



 Does anyone know how much current the B & C S702-1 starter relay draws at the "S" terminal when active?



 I know that the two large terminals will carry what I need - I'm trying to determine if the 6A (at) 12VDC capable switch that I would like to use is sufficient or whether I need a relay to drive the starter relay.

recapen(at)earthlink.net
Guest

Posted: Mon Mar 02, 2009 9:53 am Post subject: B and C Starter relay

Frank,



I like your answer........



Ralph



--

recapen(at)earthlink.net
Guest

Posted: Mon Mar 02, 2009 10:02 am Post subject: B and C Starter relay

B&C's website states "Coil resistance is 2.5 ohms."



12 divided by 2.5 equals 4.8 - I guess this is my first electrical engineering lesson?!



If this is correct, it does tell me that my switch is OK.....



--

frank.hinde(at)hp.com
Guest

Posted: Mon Mar 02, 2009 10:23 am Post subject: B and C Starter relay

Yup! 



--

AV8ORJWC

Joined: 13 Jul 2006
Posts: 1149
Location: Aurora, Oregon "Home of VANS"

Posted: Mon Mar 02, 2009 10:37 am Post subject: B and C Starter relay

A great rule of thumb is to size your switch so any surge current does not exceed 80% of its capacity.

  



  John Cox



 

  From: Ralph E. Capen

Sent: Mon 3/2/2009 10:00 AM

To: aeroelectric-list(at)matronics.com

Subject: Re: B and C Starter relay

 [quote]--> AeroElectric-List message posted by: "Ralph E. Capen" <recapen(at)earthlink.net>  B&C's website states "Coil resistance is 2.5 ohms."  12 divided by 2.5 equals 4.8 - I guess this is my first electrical engineering lesson?!  If this is correct, it does tell me that my switch is OK.....  --

nuckolls.bob(at)aeroelect
Guest

Posted: Mon Mar 02, 2009 3:32 pm Post subject: B and C Starter relay

At 10:35 AM 3/2/2009, you wrote:

 	  Quote: 	
		  

<recapen(at)earthlink.net>



Does anyone know how much current the B & C S702-1 starter relay 

draws at the "S" terminal when active?



I know that the two large terminals will carry what I need - I'm 

trying to determine if the 6A (at) 12VDC capable switch that I would 

like to use is sufficient or whether I need a relay to drive the starter relay.


	


  That switch will be fine. The contactor draws a lot more

  that a continuous duty battery contactor (typically 4A

  versus 1A) but the REAL concern for switch life has

  to do with the catch diode being installed on the coil.

  If B&C is buying the same part I used to sell as S702-1,

  the diode is built in. If you look on the bottom mounting

  plate, you should see some words speaking to "suppression"

  stamped in the metal.



  What kind of switch are you talking about? Does it have

  a nice "snap" action?

        Bob . . .



        ----------------------------------------)

        ( . . .  a long habit of not thinking   )

        ( a thing wrong, gives it a superficial )

        ( appearance of being right . . .       )

        (                                       )

        (                  -Thomas Paine 1776-  )

        ----------------------------------------

recapen(at)earthlink.net
Guest

Posted: Tue Mar 03, 2009 4:23 am Post subject: B and C Starter relay

It does have the "suppression" marks - good #1.

The switch has a real good push and release (momentary) action - I don't 

have the number here - but I am happy with the action.



---

nuckolls.bob(at)aeroelect
Guest

Posted: Tue Mar 03, 2009 11:17 am Post subject: B and C Starter relay

At 06:14 AM 3/3/2009, you wrote:

 	  Quote: 	
		  

<recapen(at)earthlink.net>



It does have the "suppression" marks - good #1.

The switch has a real good push and release (momentary) action - I 

don't have the number here - but I am happy with the action.


	


   You're good to go . . .



        Bob . . .



        ----------------------------------------)

        ( . . .  a long habit of not thinking   )

        ( a thing wrong, gives it a superficial )

        ( appearance of being right . . .       )

        (                                       )

        (                  -Thomas Paine 1776-  )

        ----------------------------------------

recapen(at)earthlink.net
Guest

Posted: Tue Mar 03, 2009 11:43 am Post subject: B and C Starter relay

Thanks!



--

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