Subject: Should I work a kill switch into my shop wiring?

From: John Halbur <[email-masked]>
Date: 28 Mar 1997 06:32:50 GMT

I have been waffling over whether or not to put a kill switch (or switches) on the 
outlets for tools (don't want to kill the lights!) in my new backyard workshop.  I 
am about to start running the wiring in the shop.  I was thinking to put a bank of 
20 amp double pole switches near the door with each switch killing one or two branch 
circuits.  This obviously adds a bit to the cost of the wiring job and everyone I 
talk to about this (none of them are woodworkers) look at me like I'm looney for 
even thinking about it.  Are kill switches really overkill?

Also, is there a better way to switch off the branch circuits that isn't too 
expensive?  I had thought to use a multi-pole contactor, but the $200+ cost made me 
change my mind.

John Halbur

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From: Dave Druckerman <[email-masked]>
Date: Fri, 28 Mar 1997 02:58:57 -0800

> expensive?  I had thought to use a multi-pole contactor, but the $200+ cost made me

John,

I believe that this really boils down to who is going to be using and/or
having access to your shop.  If it's just yourself, then I see no real
benefit to having kill switches.  If, on the other hand, there will be
some neophytes working out there with you, then it's probably a
reasonable peace-of-mind addition.  

I still remember high school shop had kill switches that shut off all of
the outlets and all of the stationary power tools at once.  Big red
mushroom push buttons on each wall, with a seperate key locked reset. 
Instructor used to push it five minutes before the end of each class to
make sure that all of us little sh#*s (his phrase, not mine) would clean
up rather than run out.  Don't think I ever knew where the relays were,
but they made one heck of a sound when they kicked out.  (Oh, what I
wouldn't give for that 20" Delta variable speed industrial bandsaw and
16" jointer now...what a waste to put into a high school shop!)  

Anyways, if you are serious about the kill switches, you really should
have one (or multiple in series) button that kills everything.  Last
thing you want in an emergency is to be guessing which switch to throw. 
It seems to me that would defeat your purpose.  If you want to go that
route, you're getting into some significantly higher expense.  Would
require contactors (relays) on each circuit.  This typically requires an
industrial level electrician.

My two cents.

Dave Druckerman

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From: [email-masked] (Tom Gauldin)
Date: Fri, 28 Mar 1997 16:47:56 GMT

Dave Druckerman <[email-masked]> wrote:

>> outlets for tools (don't want to kill the lights!) in my new backyard workshop.  

I sense that you're wiring your shop by extending a 100 amp or so line to the
shop and feeding a distribution panel that would serve the needs of your
tools.  Here's a suggestion, then,

You might consider feeding two adjoining panels.  One would be for the lights
and would not have its own main circuit breaker.  Beside it would be a second
panel that would have a 100 amp main breaker disconnecting all other breakers
in the panel.  When you left the shop for the day, you could just flip off the
main on that panel, which would kill all the circuits you intended to have
dead.  At the same time,  you'd have the flexibility of deciding whether NEW
circuits would go to the "continuously on" panel or the one that you would
kill each night.  

Tom
Tom Gauldin           Here's to the land of the longleaf pine,
Raleigh NC             The Summerland,where the sun doth shine.
fax 919-676-1404   Where the weak grow strong,and the strong grow great,
                               Here's to Downhome,the Old North State.

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From: [email-masked]
Date: Fri, 28 Mar 1997 22:24:17 GMT

It all depend on how much you value your and others safety!
I have Panic style switches on everything. I have 2 separate panels
for equipment. 1for 120volt and 1for 220volt. Every outlet,plug etc.
is on its own breaker. Yes it is over kill but I am very happy with
it. And realistically if you are building YOUR shop for the long haul
it works out to virtually zero cost in the long run.
Best,dave f..
"Common sense is so...uncommon."FLW
remove X to reply..

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From: [email-masked] (Joe Stockton)
Date: 29 Mar 1997 01:32:13 GMT

>> I have been waffling over whether or not to put a kill switch (or
switches) on the  outlets for tools (don't want to kill the lights!) in
my new backyard workshop.  I  am about to start running the wiring in
the shop.  I was thinking to put a bank of  20 amp double pole switches
near the door with each switch killing one or two branch  circuits. 
This obviously adds a bit to the cost of the wiring job and everyone I 
talk to about this (none of them are woodworkers) look at me like I'm
looney for  even thinking about it.  Are kill switches really overkill?
<<

There overkill until you need to turn everything off quickly or easily
due to an accident, machine problem, etc. Then they're priceless!

>> Also, is there a better way to switch off the branch circuits that
isn't too  expensive?  I had thought to use a multi-pole contactor, but
the $200+ cost made me  change my mind. <<

The inexpensive way is to put all machines on a subpanel and connect the
kill switch to short across the subpanel main breaker. Using a
momentary, normally open (NO) switches with a large red mushroom head
with a couple of them mounted in convenient locations in the shop. When
one of the buttons is pressed, the breaker is shorted, quickly overload
and trips. Obviously, the lights _must_ be feed from a circuit that is
not in the subpanel.

This is a little additional work especially if you can not easily have
the subpanel and separate light circuit. Fortunately for me, this won't
be a problem in the shop I'm setting up in my basement so I will be
installing kill switches.

Call me paranoid but I still have all my appendages as well as most my
hearing (lost at an earlier, more foolish age) and vision (lost to
inherieted severe near sightedness). And I'm trying to keep it that way.

--

--\  Joe Stockton
---> [email-masked]
--/  Lawrenceville GA USA

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From: [email-masked] (Michael Rainville)
Date: Sat, 29 Mar 1997 19:56:53 GMT

What you do how you do it depends on your purpose for wanting to
"kill" the power. If you want to simply be sure that someone doesn't
come along and accidently turn on a machine, keep them unplugged. 

I'm not sure if you are planning a subpanel but I would suggest it for
many reasons. For my peace of mind in my old shop I simply flipped off
the circuit breakers when I closed up at night. Thus I could be sure
something hot wasn't left on or some wire wouldn't catch in some
sawdust. In the warm months I shut off the main breaker, in the colder
months, I shut off all circuit breakers except for the furnace.

I am sure there are those that will say this is not a proper use of
the breakers but it didn't cost anything extra except for two that I
replaced over a 12 year period.  

Some people thought I was a little overboard, I'm not a safety nut
either, but the fire dept was pleased when they had to come one night
and didn't have to worry about hot wires.

Mike Rainville

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From: [email-masked]
Date: Sun, 30 Mar 1997 21:28:41 -0800

I put a three pole 30 amp contactor in my panel and turn it on with my
light switch.
I picked contactor up for free,I think cost is about 30 bucks. NEVER tie
wires to the main breaker and short it out you could shut the
neighborhood down breakers are not made to be shorted that way. They
make a shunt trip breaker you could use but it is costly.
I would use one or two 3 pole contactors or a 60 amp and a sub panel.

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From: Larry Gutkowski <[email-masked]>
Date: Mon, 31 Mar 1997 14:04:49 -0800

I recently had a 60 amp panel run from my main. I waffled as to whether
I would install a "master" swtich to the subpanel. In the end, that's
what I did, and I am _extremely_ glad I did. My motive was not for a
"kill" switch as much as for a "lock-out" switch. My shop is actually my
garage that my young boys have access to. I don't let them play around
my tools especially when I am working. But every once in a while, I'll
have to run into the house (e.g., bathroom) for a moment. I have _great_
peace of mind knowing I can kill the power to _every_ tool with one
switch. I can (and do) also lock the switch (5.5 feet off the ground) to
prevent kids from turning it on. My garage lights are on a separate
circuit off the main panel.

The only problem I have is for my rechargeable tools. If I cut the power
to all of the outlets, not much charging is going to happen. As such I
like the suggestion below by Tom Gauldin.

The next thing I would like to do is install some sort of glowing pilot
light that tells me when the subpanel is energized. I can certainly tell
right now by observing the position of the switch handle. But a light
would catch my attention more. There have been times where I've gone out
to the garage and noticed I forgot to flip the switch off (my tools were
put away and unplugged of course).

Larry