CO relay?

[Svart]

What is a CO relay?

I thought i read it in a post on here but searching seems to be messed up as I keep getting the same 270 matches no matter what I type in.. :shock:

I am used to reading DPDT-NC etc..

Does CO mean constant open or something?

I am buying some for the G9.

EDIT: I found a thread with the relays in them, apparently CO means "change over" so it would be DPDT..

But I still cannot find if it should be NO or NC on the primary contacts.. I can get both.

 

[Svart]

Oh and before someone tells me to go ohm out the PCB to find the answer..

I'm at work and can't do that right now.. :?

But I can order stuff online!

 

[TomWaterman]

Change over. :thumb:
If you D/L a PDF spec sheet it will be clear in the drawings.

Tom

 

[Svart]

oh I understand the relays it's what the PCB needs, should the main leads be NO or NC?

 

[Swedish Chef]

NO= Normally Open
NC= Normally Closed!
:thumb:

sc

 

[NewYorkDave]

My knee-jerk reaction was to say "central office" until I remembered otherwise. :wink:

Hey, C.O.s did use a heckuva lot of relays at one time. The noise could be deafening.

 

[Svart]

thanks Chef, but I know that they mean! :green:

i was wondering what type of relay should i use for the G9.

i can get both DPDT-NC and DPDT-NO meaning that the unpowered relay can either be contacting the common pin and either one of the other pins depending on what I buy..

 

[Guest]

Depends what you want it to do

If you have to push in to make somethign happen - get a NO
ie the circuit is not normally in

example of this would be the Q button on the Calrec.
Push to make it happen - ie get a NO

(I hope)

 

[PRR]

> both DPDT-NC and DPDT-NO

I don't understand. NC and NO only make sense on single-throw switches.

 

[CJ]

Yes, if its a form C relay, you get two for the price of one. And usually a spare set of three terminals on the other side. Good for LED indication.

Here is (from bottom to top) a single NO/NC, a double NO/NC, and a double NO/NC with an extra set of terminals.
5 bucks to the first geek who can tell me what that extra set of terminals controls.

 

[Svart]

why CJ that is a latching coil relay and has a second coil.

PRR,

the same concept applies to DPDT relays as SPDT. lets take the Zettler relays CJ has in his picture for example:

pins 1 and 16 are coil
pins 3,14 are common
5,12 are NC
7,10 are NO

for this manufacturer I believe that this is the only config. For others they give the option of having the pins that are usually NO between manufacturers to be NC and the NCs to be NOs so it would read like this:

1,16 coil
3,14 common
5,12 NO
7,10 NC

depending on what I buy I could have the reverse actuation of what I want in the unit..

that's what I am trying to figure out.

 

[CJ]

svart wins 5 dollar

 

[Svart]

I have some 35A 600v power contactors here at work.. :shock:

I had a load of around 5A@150VDC going though one of these a long time ago.. I was put on the job of figuring out why they were burning out. maybe it was the HUGE arcing on make AND break.. I got an arc to jump 1" from the contact to the case of the box upon breaking the contact during motor regen.. burned a nice hole in 16ga. :green:

Oh and in case you wondered.. huge flywheel diodes and snubber networks turned that arc into a tiny little spark.. just enough to clean the contacts.

been working fine ever since.

 

[CJ]

Where is that post with the PG and E arc in Nevada somewhere?
Sub station lightening.

Contactors are a pain. We have one here to test GFI's for false tripping.
Keeping a 5 ma ground fault from tripping when it is next to a contactor can be tough. Used some conductive spray coating on the plastic case but the jerk's forgot to ground it!
Oh well. Warm fuzzy feeling for the customer more than anything.
Maybe someone could use this stuff on a project or something: