ON/OFF Switch questions

So, its time to make the last few decisions and purchases to implement Phase I of my eHERMS build.

I'm currently trying to figure out a master power/emergency shut off switch setup.

I'll have 50amp 240 comming in and 15amp 120 comming in. I'd like a single switch to turn on off and act as an emergency kill switch as well.

I'm assuming I'll need a relay setup... but I'm confused a bit how all that will work. Anyone have any advice?

I'de just use a small breaker box, and circut breakers.

You may just want to go with something mechanical. Though a relay is fairly reliable there are time where they can fail. A manual disconnect switch might be better. A knife blade switch or air conditioner disconnect.

50a is huge. You might have a tough time finding something cheap. Check ebay for industrial stop/emergency switches. They are pricey but you might get a deal.

I am not taking my own advice. I have two SSR's on my 240v One for the PWM and one to a switch on my panel as a "Power Off/emergency" switch. On my 120v I am using a 20a mechanical relay to do the same.

Edit: When I was looking at emergency switches. They had different backs you could get. You could get a switch that would turn the 120v and the 240v off at the same time. Not sure how much that would cost though.

I just put two toggle switches on mine. One kills the 120V and the other kills the control voltage to the contactor for my heating element. You could also do this with one 2-pole toggle switch. This, however does not kill the power to my control panel...

If you want to kill all power to the controller, you could run all hot legs through a 3-pole switch of some sort rated for at least 50A. Maybe a used 60A 3-pole safety switch?

Disconnect You can and should also add the remote handle in this case. Doesn't help you with the seperate 120v however. You can divide 120v out of it, if your incoming power is enough for both loads.

I've got my spa disconnect panel that I Can use as a big kill.... but I still want to be able to have a quick, no thought, emergency shutoff.

Here is a safety switch. Look for non-fusible and I am sure you will find something cheaper.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=110429151483&rvr_id=&crlp=1_263602_263622&UA=WXI8&GUID=df26163f1230a0437213dc63ffe19be2&itemid=110429151483&ff4=263602_263622

We covered this pretty extensively toward's then end of Ohio-Ed's Electrical question thread.
https://www.homebrewtalk.com/f51/electric-question-153310/
50A contactors are available from auberins for $14.

CodeRage said:

We covered this pretty extensively toward's then end of Ohio-Ed's Electrical question thread.
https://www.homebrewtalk.com/f51/electric-question-153310/
50A contactors are available from auberins for $14.

Click to expand...

Ahh... there has been more since I last read that thread....