identifying relay pins

Printed From: the12volt.com
Forum Name: Relays
Forum Discription: Relay Diagrams, SPDT Relays, SPST Relays, DPDT Relays, Latching Relays, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=121395
Printed Date: May 09, 2025 at 11:03 AM

Topic: identifying relay pins

Posted By: juavos00
Subject: identifying relay pins
Date Posted: April 17, 2010 at 5:18 PM

First off sorry for the crappy paint drawing, but thats as good as I could do. Anyway I need help identifying the pins on this relay. (85,86,87,87a,30) Thanks

posted_image

Replies:

Posted By: t&t tech
Date Posted: April 17, 2010 at 5:27 PM

85- Negative side of relay coil*

86- Positive side of relay coil*

30- Common terminal of relay,

87a- Normally closed terminal (closed to pin 30 when relay is inactive, and open when active)

87- Normally open pin, (open when inactive, closed to pin 30 when relay is active)

*Applying power and ground to the respective termnal activates the relay!

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COMMIT YOUR WAY TO JEHOVAH AND HE WILL ACT IN YOUR BEHALF. PSALMS 37:5

Posted By: t&t tech
Date Posted: April 17, 2010 at 5:29 PM

In the diagram you have however

Pins 1 and 2 would be the coil

pin 3 is common, 4 is normally closed and 5 normally open!

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COMMIT YOUR WAY TO JEHOVAH AND HE WILL ACT IN YOUR BEHALF. PSALMS 37:5

Posted By: juavos00
Date Posted: April 17, 2010 at 5:30 PM

thanks for the reply, but that doesn't help me much. I know about what each pin does, but that is why I drew the picture with the numbers on them hoping someone would say.. 1 = 85 2 = 86, so forth and so on.

Also does it matter if the positive and negative are switched?

Posted By: juavos00
Date Posted: April 17, 2010 at 5:31 PM

sorry couldnt post before you answered my question..

But does the positive and negative matter?

Posted By: oldspark
Date Posted: April 17, 2010 at 7:30 PM

Not in this case - you relay uses a resistor across the coil (not a diode to quench the coil spark).

Posted By: i am an idiot
Date Posted: April 17, 2010 at 9:09 PM

1 = 85

2 = 86

3 = 30

4 =87A

5 = 87

Posted By: howie ll
Date Posted: April 18, 2010 at 12:21 PM

I think that relay is Italian, the convention is pin 1 (85 on the ISO listing) is normally the neg. side of the coil.

Posted By: t&t tech
Date Posted: April 18, 2010 at 3:25 PM

My bad! You should have explained yourself better!

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COMMIT YOUR WAY TO JEHOVAH AND HE WILL ACT IN YOUR BEHALF. PSALMS 37:5

Posted By: juavos00
Date Posted: April 18, 2010 at 8:03 PM

I have wired in my relay thanks to all of your help.. Mods can you please lock and/or delete this thread. Thanks