"Brett A. Thomas" wrote in message
...
Ok, almost got it then, I think. Thank you, you've saved me many hours!

So, I get three or four button and contactor blocks, like this one:


http://web4.automationdirect.com/adc/Shopping/Catalog/Pushbuttons_-z-_Switches_-z-_Indicators/Eaton_Cutler-Hammer_22mm_(E22_Series)/Emergency_Stop_-z-_Mushroom_Pushbuttons_-a-_Stations/E22JLB2N8B

I then connect them to a 40 amp, 24 volt contactor, such as this 2 pole
model:

http://store.yahoo.com/waterheater/c2con40amp2p.html

I also connect one side of the contactor to a 30 amp/220 volt circuit on
my existing subpanel, and the other side to the input of the new subpanel.

Assuming all this is correct, I only have one question - does the
contactor step the 220 down to 24v for the buttons? Or do I need a
seperate transformer to do that? Something like this, maybe?


http://www.surpluscenter.com/item.as...tname=electric


A contactor is just a big relay and steps down nothing. You will need a 24V
source You will also need a N.O. momentary contact switch (probably a key
type) and a 24V relay to complete your system. Now I know that this sounds
confusing but let me explain where I'm coming from. With what you seem to
be describing, you are going to connect your contactor between the existing
sub panel and a new one that will be switched by it. This is cool and is
something I am considering as well. To control the contactor, it looks like
you are going to hook up its field coil to a 24V source with 3 or 4 push
button shut down switches in a loop configuration so that if any of the
buttons are pressed, the contactor will open and kill the power. While this
sounds good, there are a couple of problems. These push button switches are
momentary action type which means that they only work when held in position.
IOW, they will open (turn off) only for as long as you hold the switch. Now
this is where problem comes in. If your 24V source is getting power from
something that is not controlled by the contactor, the contactor will only
open (cut power) when one of the switches is being pressed and as soon as
you let it go, the power will be restored to the contactor and it will close
again and re-power the new box. This will not be of much help. If you
supply power to the 24V source comes from the contactor supplied side, you
will never have power to turn the contactor on. So what do you need to do??
You need to build a self energizing relay to control the contactor and that
is where the 24V relay comes in and you will need a momentary contact N.O.
switch to activate it.. I can email you a schematic if you need it



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