Wiring of a 12V 4PDT Relay

Consider the pins to be in four rows of three - these are your four poles, and the sets of three will be a common (Com) pin, one which is normally-closed (NC) and one normally-open (NO).

The pins 13 and 14 on your new relay are the coil and correspond to 4 and 12 on the original one. The other pins on the original are:

NC NO Com

When the relay is energized, the common contact switches over and connects to the normally-open. So you may be able to tell which are the common, NO and NC by looking (if it's a clear case) or by testing (multimeter and battery). Check resistance or continuity between pins to confirm which pin is which before and after energizing the coil. If the relay is marked with a polarity for the coil then connect up the battery in that direction otherwise either way is fine.

If you still have doubts post the pinout and we'll give you a direct pin-for-pin chart.

Cheers.

Ken

Thanks for the quick response. I am still a little confused.

The relay I have looks like this

5 6 7 8

13 14

The case is clear and I can see that 1-9, 2-10, 3-11, 4-12 are normally closed. When power is applied across the coil (13&14), 1-5, 2-6, 3-7,

A pin-for-pin chart would be great because I can't figure out how to match up what was written above to my relay.

Thanks for your patience.

Sam

Thanks for the quick response. I am still a little confused.

The relay I have looks like this

5 6 7 8

13 14

The case is clear and I can see that 1-9, 2-10, 3-11, 4-12 are normally closed. When power is applied across the coil (13&14), 1-5, 2-6, 3-7,

A pin-for-pin chart would be great because I can't figure out how to match up what was written above to my relay.

Thanks for your patience.

Sam

Hi Sam. Good sleuthing. :-)

Old relay New relay

Someone better than me might figure it out but I don't see how that first relay can be 4PDT, but I admit to being half asleep still. Anyway, there's a suitable pin-for-pin table for you.

Cheers.

Ken

Based on your instruction book...

Try writing a "truth table" that goes like this:

WHEN POWER IS NOT APPLIED TO COIL

Blue wire is not connected to anything Red wire is connected to green wire etc

WHEN POWER IS APPLIED TO COIL

Blue Wire is connected to yellow wire Red wire is connected to black wire

etc

Then try looking at your relay and seeing how it should be wired to match the table.

I have 30 of these 4pdt relays, they are very versatile and useful in all areas of life. I made some toy railroad control out of one, opening and closing a gate when train approaches.

- 9

I hope you can read the ascii art, does this help ?

-- Regards ......... Rheilly Phoull

Compare your new relay to the old relay to see if they are physically the same. My bet is that they are.

If they are not, we'll need a schematic of the existing wiring to see what goes where.

Normally on a 4PDT relay, the pins are grouped like this, in order left to right: NC (Normally Closed), NO (Normally Open), COM (Common)

13 14 Coil

See the picture at the bottom of:

Ed

Thank you all for your helpful answers. I was able to successfully follow the schematic and the buzzer system is working. Could not have done it without your help.

Sam