All,

Spent some time trolling the archives and Google, and couldn't really
find what I was looking for. I suspect in part it's because I'm
suffering from a Language Gap - there's a specific term for what I'm
looking for, and I don't know what it is.

So, I apologize in advance if this has been talked to death before, but
I can't find it, if it is.

First of all, my knee has recovered enough from surgery in the past week
that I've been spending my free time in the new shop (18' 6" x 19' fully
detached garage) emptying all the boxes that don't belong there,
emptying the boxes that do belong there into the hideous cabinetry out
there, running boxes to recycling, giving things to Goodwill, etc. Very
exciting! I expect to be able to set the tablesaw back up by this
weekend! February of last year was the last time I made sawdust.

The walls and ceiling in the shop are exposed studs (16" centers) right
now. I'm planning on putting drywall up on the ceiling and plywood on
the walls. But that's not what I want to talk about (THAT is easy to
find in the archives) - before I can do that, I have to get some wiring
done. To get the wiring done, I have to make some key decisions.

I'm a bit of a safety freak, and I have two small children (4 & 2).
Short term I want to keep them out of the shop entirely without
supervision, and the lock on the garage door will do well with that.
Long term, I want to let them in the shop, but not let them do anything
really dangerous without supervision (i.e., anything involving power
tools). I'm also interested in emergency power cutoffs, mostly for my
own use. Right now the garage is fed by a 240v 40 amp circuit that
terminates in a sub panel in the garage. I recognize I may need more in
the future, but it's enough for now.

Without any thought whatsoever to the practicality or cost, the two big
things I want a

A lockout box. I want to be able to leave lights and battery chargers
on, but throw a switch, put a lock on it, and have no power tools operate.

Several Big Red Buttons. I want to be able to hit a quick disconnect
from one of several places in the shop, and have it kill the power to
all the power tools (but not the lights or the battery chargers). Part
of my problem is that I do not know what the industry Term of Art is for
these buttons.

Of course, we don't live in a world where practicality and cost aren't
concerns, so if any requirement I list above is too much work or too
much expense, I'm willing to rethink. If it's gonna cost me $2000, I
can lose the emergency cutoffs and just put a lock on the subpanel I
have and be done with it.

So, here are my questions, and thanks in advance for anyone with the
knowledge to answer, the inclination to help and the patience to read
through my long-winded explanation:

1) What are Big Red Buttons called?

2) How do they work? Can I wire three circuits through one without
needing a second subpanel?

3) What are the lockout box things called? Googling for "lockout box"
gives me a bunch of storage boxes to store my lockout/tagout keys in. I
think maybe a "safety switch" is what I want, something like this:
http://www.builderdepot.com/browse.i...odstoreid=2245

4) How do *they* work? Can I wire three circuits through one without
needing a second subpanel?

5) If you held a gun to my head and said "Do it right now with what you
know," I'd drop the emergency cutoff switches for now, install a new
subpanel on a 30A breaker, and put a "safety switch" between the two of
them. Is this, in fact, the best plan, or am I artificially limiting
myself by my lack of knowledge?

6) Stupid question - I have this kooky idea to hook up a 50 ampish
inline AC ammeter prior to the first subpanel. Is this stupid, or just
geeky? I think it'd be pretty cool to always know how much juice I'm
pulling.

Thanks in advance...

-BAT

On Thu, 09 Dec 2004 11:40:38 -0800, Brett A. Thomas wrote:
All,

Spent some time trolling the archives and Google, and couldn't really
find what I was looking for.

Just so you know, the word "trolling" in Usenet terms has a pretty
specific meaning, something along the lines of "posting controversial
messages to stir up people and prolong a useless discussion", which
I don't think is what you're really doing.


Without any thought whatsoever to the practicality or cost, the two big
things I want a
A lockout box. I want to be able to leave lights and battery chargers
on, but throw a switch, put a lock on it, and have no power tools operate.

The easiest way to do this would be to have the big power tools on a
sub-panel, and the outlets on the main panel. Master-switch the whole
sub-panel on and off.

Several Big Red Buttons. I want to be able to hit a quick disconnect
from one of several places in the shop, and have it kill the power to
all the power tools (but not the lights or the battery chargers).

Yup.

Part
of my problem is that I do not know what the industry Term of Art is for
these buttons.

"Emergency Stop" is what most/all of them seem to be marked with.

Of course, we don't live in a world where practicality and cost aren't
concerns, so if any requirement I list above is too much work or too
much expense, I'm willing to rethink. If it's gonna cost me $2000, I
can lose the emergency cutoffs and just put a lock on the subpanel I
have and be done with it.

I can't see the e-stop switches adding much cost, even if you run conduit
from them back to the contactor (we call 'em relays). It's easy but
time-consuming work, so it's worth considering doing yourself if you
can get an Electrician to do the design and advise you.

So, here are my questions, and thanks in advance for anyone with the
knowledge to answer, the inclination to help and the patience to read
through my long-winded explanation:

1) What are Big Red Buttons called?

See above.

2) How do they work? Can I wire three circuits through one without
needing a second subpanel?

Put 'em before the subpanel with all the switched stuff, and let them
control the relay for the whole subpanel.

5) If you held a gun to my head and said "Do it right now with what you
know," I'd drop the emergency cutoff switches for now, install a new
subpanel on a 30A breaker, and put a "safety switch" between the two of
them. Is this, in fact, the best plan, or am I artificially limiting
myself by my lack of knowledge?

No, you're doing it right, the big red buttons juust control that subpanel.

6) Stupid question - I have this kooky idea to hook up a 50 ampish
inline AC ammeter prior to the first subpanel. Is this stupid, or just
geeky? I think it'd be pretty cool to always know how much juice I'm
pulling.

It's geeky. I'd do it, and wish I had thought of it. Let us know how
that goes, I may just retrofit my shop.

Dave Hinz

Dave Hinz wrote:
On Thu, 09 Dec 2004 11:40:38 -0800, Brett A. Thomas wrote:
I can't see the e-stop switches adding much cost, even if you run conduit
from them back to the contactor (we call 'em relays). It's easy but
time-consuming work, so it's worth considering doing yourself if you
can get an Electrician to do the design and advise you.

Dave,

Thanks for the info so far, this has helped a lot.

I'm planning on doing it myself, which is part of why I'm really trying
to understand the components.

So, it sounds like what I want is an "emergency stop" button, but the
key thing I needed to know is that it's connected to a "contactor." I
get a big red button, say, one of these beauties:

http://www.recycledgoods.com/Product...roductID=12196

And hook it to a "contact block," which then runs (24 V?) back to a
relay at the subpanel which causes the shutoff. Is that correct, and,
are there any other special terms that would be helpful in searching for
suppliers?

Thanks again. Oh, and for those searching Usenet archives in the futu

Big Red Button = Emergency Stop button hooked to a contact block or
contactor. You might also be looking for a relay, emergency switch or a
switch.

If someone had done that ten years ago I wouldn't be bugging you folks,
now.

-BAT

Sorry to follow up to my own follow up, but I think I've figured out more.

It looks like I hook up a button/contact block. I like the look of 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

That's an "N.C." which I presume stands for "Normally closed." So, when
you push it, it opens a circuit (briefly? Until it's pulled back out or
released some other way?)

That circuit is then hooked up to - what? A relay, I guess, but is
there a special name for it? Or do I just get a 30A relay someplace?
And what voltage (and AC or DC) do I run the contact blocks at?

If I figure it out on my own, I'll followup here...

-BAT

On Thu, 09 Dec 2004 13:02:20 -0800, Brett A. Thomas wrote:
Sorry to follow up to my own follow up, but I think I've figured out more.

OK!

That's an "N.C." which I presume stands for "Normally closed." So, when
you push it, it opens a circuit (briefly? Until it's pulled back out or
released some other way?)

As long as you hold it, which is long enough to trip the relay and/or
breaker your 24v is controlling.

That circuit is then hooked up to - what? A relay, I guess, but is
there a special name for it? Or do I just get a 30A relay someplace?
And what voltage (and AC or DC) do I run the contact blocks at?

The control circuit is usually 24v (AC - it'd be spelled 24V if it was DC).

I'd switch the whole subpanel rather than a bunch of individual breakers,
it's cheaper that way. Current capacity of the contacter (relay) should be
more than the total current of the breakers it's feeding.

Many buttons to control one relay, which switches off many breakers in
the entire subpanel all at once. Simplest, most cost-effective
way to do what you want to do, I think.

Dave Hinz

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

Thanks again!

-BAT

Dave, if he switched the whole subpanel then how would he still have lights?
He'd have to have a separate sub panel for the lights and batteries and
whatever else he didn't want switched. I think that was an original
requirement....not sure if it changed.

I'd switch the whole subpanel rather than a bunch of individual breakers,
it's cheaper that way. Current capacity of the contacter (relay) should
be
more than the total current of the breakers it's feeding.

Dave Hinz

Sounds like a lot of locks, when the best solution might be a lock on the
garage/shop door. Kids don't need to be playing unsupervised in a garage
even if it only houses the family car.

--
********
Bill Pounds
http://www.billpounds.com


"Brett A. Thomas" wrote in message
...
All,

Spent some time trolling the archives and Google, and couldn't really
find what I was looking for. I suspect in part it's because I'm
suffering from a Language Gap - there's a specific term for what I'm
looking for, and I don't know what it is.

So, I apologize in advance if this has been talked to death before, but
I can't find it, if it is.

First of all, my knee has recovered enough from surgery in the past week
that I've been spending my free time in the new shop (18' 6" x 19' fully
detached garage) emptying all the boxes that don't belong there,
emptying the boxes that do belong there into the hideous cabinetry out
there, running boxes to recycling, giving things to Goodwill, etc. Very
exciting! I expect to be able to set the tablesaw back up by this
weekend! February of last year was the last time I made sawdust.

The walls and ceiling in the shop are exposed studs (16" centers) right
now. I'm planning on putting drywall up on the ceiling and plywood on
the walls. But that's not what I want to talk about (THAT is easy to
find in the archives) - before I can do that, I have to get some wiring
done. To get the wiring done, I have to make some key decisions.

I'm a bit of a safety freak, and I have two small children (4 & 2).
Short term I want to keep them out of the shop entirely without
supervision, and the lock on the garage door will do well with that.
Long term, I want to let them in the shop, but not let them do anything
really dangerous without supervision (i.e., anything involving power
tools). I'm also interested in emergency power cutoffs, mostly for my
own use. Right now the garage is fed by a 240v 40 amp circuit that
terminates in a sub panel in the garage. I recognize I may need more in
the future, but it's enough for now.

Without any thought whatsoever to the practicality or cost, the two big
things I want a

A lockout box. I want to be able to leave lights and battery chargers
on, but throw a switch, put a lock on it, and have no power tools operate.

Several Big Red Buttons. I want to be able to hit a quick disconnect
from one of several places in the shop, and have it kill the power to
all the power tools (but not the lights or the battery chargers). Part
of my problem is that I do not know what the industry Term of Art is for
these buttons.

Of course, we don't live in a world where practicality and cost aren't
concerns, so if any requirement I list above is too much work or too
much expense, I'm willing to rethink. If it's gonna cost me $2000, I
can lose the emergency cutoffs and just put a lock on the subpanel I
have and be done with it.

So, here are my questions, and thanks in advance for anyone with the
knowledge to answer, the inclination to help and the patience to read
through my long-winded explanation:

1) What are Big Red Buttons called?

2) How do they work? Can I wire three circuits through one without
needing a second subpanel?

3) What are the lockout box things called? Googling for "lockout box"
gives me a bunch of storage boxes to store my lockout/tagout keys in. I
think maybe a "safety switch" is what I want, something like this:

http://www.builderdepot.com/browse.i...odstoreid=2245

4) How do *they* work? Can I wire three circuits through one without
needing a second subpanel?

5) If you held a gun to my head and said "Do it right now with what you
know," I'd drop the emergency cutoff switches for now, install a new
subpanel on a 30A breaker, and put a "safety switch" between the two of
them. Is this, in fact, the best plan, or am I artificially limiting
myself by my lack of knowledge?

6) Stupid question - I have this kooky idea to hook up a 50 ampish
inline AC ammeter prior to the first subpanel. Is this stupid, or just
geeky? I think it'd be pretty cool to always know how much juice I'm
pulling.

Thanks in advance...

-BAT

Brett A. Thomas wrote:
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

Thanks again!

-BAT


You might want to consider some start buttons to turn it all back on.
They make pushbutton stations that have large "panic" buttons for the
stop button and also include a start. Also, check your codes as to what
gauge wire is going to need to feed your subpanel. See if they will
allow your particular setup.

I have some of those definite purpose contactors and didn't really know
a use for them. Now you have me thinking. I'm not plannning what you're
planning. But, the noggin is smoking. As I've never used one and don't
know their proper wiring, I do have this question. Can several
pushbutton stations operate the same contactor or would there need to
be a series of contactors? I've only wired magnetic starters and one
per machine. I haven't tried to feed a subpanel with them.

I look forward to seeing how this thread progresses when some of the
electrician types get home from work.
Eric T. in MN

ps. Brett, where are you located?

Brett A. Thomas wrote:
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

Thanks again!

-BAT


You might want to consider some start buttons to turn it all back on.
They make pushbutton stations that have large "panic" buttons for the
stop button and also include a start. Also, check your codes as to what
gauge wire is going to need to feed your subpanel. See if they will
allow your particular setup.

I have some of those definite purpose contactors and didn't really know
a use for them. Now you have me thinking. I'm not plannning what you're
planning. But, the noggin is smoking. As I've never used one and don't
know their proper wiring, I do have this question. Can several
pushbutton stations operate the same contactor or would there need to
be a series of contactors? I've only wired magnetic starters and one
per machine. I haven't tried to feed a subpanel with them.

I look forward to seeing how this thread progresses when some of the
electrician types get home from work.
Eric T. in MN

ps. Brett, where are you located?

Pounds on Wood wrote:
Sounds like a lot of locks, when the best solution might be a lock on the
garage/shop door. Kids don't need to be playing unsupervised in a garage
even if it only houses the family car.

Well, in the short term that's the plan - when they're this age, they
never need to be out there.

I know when I was, say 12, I spent a lot of time relatively unsupervised
in the garage. I don't think they should have to get me to get a
(neander) saw. My *hope* is that, when they're that age, I won't have
to worry about them around power tools, either - I know when I was 12
you couldn't've paid me enough to turn on my Grandfather's radial arm
saw, I thought it was terrifying (even though I'd worked on it with
him). But we won't know for sure until we get there, and there are
always kids' friends who may be over and less intelligent than my own
genius progeny . Whatever the exact age, I expect that there will be
a point when I'm willing to trust them to use neander tools but not
power tools.

-BAT

robdingnagian1 wrote:
You might want to consider some start buttons to turn it all back on.
They make pushbutton stations that have large "panic" buttons for the
stop button and also include a start. Also, check your codes as to what
gauge wire is going to need to feed your subpanel. See if they will
allow your particular setup.

Yes, that's actually one of my questions - exactly how do I turn this
back on? And, obviously, I'll need to include my building inspector in
all this. But I need to be able to talk vaguely intelligently about
what I'm going to do, first.

As to the question, I think of two basic possibilities:

Either, as you suggest, there needs to be a "turn it all back on" switch
that resets the relay somehow, or, the way this is *supposed* to be
wired is so that, when the relay closes, it causes a dead short and
trips the breaker on the original subpanel, and when the power cuts the
relay opens automatically. I have no opinion about whether that's a
good idea, or if it works, but, if it's not, I'm expecting to get flamed
right about now.

All the threads I've seen previously on this subject have tended to the
"tell an electrician you want emergency stops" type of answers, but it
doesn't seem to me this should really be rocket science, and I hope we
can figure it out and document it for everyone else.

ps. Brett, where are you located?

I'm in San Carlos, CA.

-BAT

Ron Short wrote:
Dave, if he switched the whole subpanel then how would he still have lights?
He'd have to have a separate sub panel for the lights and batteries and
whatever else he didn't want switched. I think that was an original
requirement....not sure if it changed.

One of my original questions was "do I need a second subpanel?" and it
seems like the answer is "yes."

-BAT

Brett A. Thomas wrote:

All,

Spent some time trolling the archives and Google, and couldn't really
find what I was looking for. I suspect in part it's because I'm
suffering from a Language Gap - there's a specific term for what I'm
looking for, and I don't know what it is.

So, I apologize in advance if this has been talked to death before,
but I can't find it, if it is.

First of all, my knee has recovered enough from surgery in the past
week that I've been spending my free time in the new shop (18' 6" x
19' fully detached garage) emptying all the boxes that don't belong
there, emptying the boxes that do belong there into the hideous
cabinetry out there, running boxes to recycling, giving things to
Goodwill, etc. Very exciting! I expect to be able to set the
tablesaw back up by this weekend! February of last year was the last
time I made sawdust.

The walls and ceiling in the shop are exposed studs (16" centers)
right now. I'm planning on putting drywall up on the ceiling and
plywood on the walls. But that's not what I want to talk about (THAT
is easy to find in the archives) - before I can do that, I have to get
some wiring done. To get the wiring done, I have to make some key
decisions.

I'm a bit of a safety freak, and I have two small children (4 & 2).
Short term I want to keep them out of the shop entirely without
supervision, and the lock on the garage door will do well with that.
Long term, I want to let them in the shop, but not let them do
anything really dangerous without supervision (i.e., anything
involving power tools). I'm also interested in emergency power
cutoffs, mostly for my own use. Right now the garage is fed by a 240v
40 amp circuit that terminates in a sub panel in the garage. I
recognize I may need more in the future, but it's enough for now.

Without any thought whatsoever to the practicality or cost, the two
big things I want a

A lockout box. I want to be able to leave lights and battery chargers
on, but throw a switch, put a lock on it, and have no power tools
operate.

Several Big Red Buttons. I want to be able to hit a quick disconnect
from one of several places in the shop, and have it kill the power to
all the power tools (but not the lights or the battery chargers).
Part of my problem is that I do not know what the industry Term of Art
is for these buttons.

Of course, we don't live in a world where practicality and cost aren't
concerns, so if any requirement I list above is too much work or too
much expense, I'm willing to rethink. If it's gonna cost me $2000, I
can lose the emergency cutoffs and just put a lock on the subpanel I
have and be done with it.

So, here are my questions, and thanks in advance for anyone with the
knowledge to answer, the inclination to help and the patience to read
through my long-winded explanation:

1) What are Big Red Buttons called?

2) How do they work? Can I wire three circuits through one without
needing a second subpanel?

3) What are the lockout box things called? Googling for "lockout
box" gives me a bunch of storage boxes to store my lockout/tagout keys
in. I think maybe a "safety switch" is what I want, something like
this:
http://www.builderdepot.com/browse.i...odstoreid=2245


4) How do *they* work? Can I wire three circuits through one without
needing a second subpanel?

5) If you held a gun to my head and said "Do it right now with what
you know," I'd drop the emergency cutoff switches for now, install a
new subpanel on a 30A breaker, and put a "safety switch" between the
two of them. Is this, in fact, the best plan, or am I artificially
limiting myself by my lack of knowledge?

6) Stupid question - I have this kooky idea to hook up a 50 ampish
inline AC ammeter prior to the first subpanel. Is this stupid, or
just geeky? I think it'd be pretty cool to always know how much juice
I'm pulling.

Thanks in advance...

-BAT

We called the big red buttons safety switches. They are normally
closed and wired in series to operate a contactor (relay) which would
control the power to the whole shop.

The simplest way would be to have a small subpanel to control the lights
and battery chargers you want left on and the main panel for the tools
would be fed through the contactor. Drop out the contactor with one of
the safety switches and you kill the power to the main panel. A quick
search on motor starters will find one that will do what you want for
under $200

The safety switch you noted above will do what you want manually but if
you want to use push button safety switchs you will need an enclosed
motor starter to kill the power to the main panel.

Rick

I work for a large temperature controls company and we use the contactors
you are discussing all of the time. What you are trying to do is set up an
electrical circuit where you have multiple switches wired all in series. The
voltage used to power the contactor is supplied by a transformer. It steps
the voltage down from 120 VAC to 24 VAC. One side of the transformer (the
common) is wired to the common side of the transformer, the other is wired
through the normally closed switches, one after another, to the other side
of the contactor coil. If any one switch is hit, the circuit will open
preventing the contractor from being powered, killing the power to your
power tools.

Depending on your local codes, you can mount a 24VAC transformer at the
circuit breaker panel and route the wires through the wall to the switches,
without conduit. The 24VAC transformer should be sized to handle the
contactor while not exceeding a rating of 100VA (about 4 amps). That will
meet the requirements for class 2 wiring, and can normally be run with
thermostat wire. A 40VA, 24 VAC transformer will more than do the job for
you assuming a typical 30 or 40 amp contactor.

"robdingnagian1" wrote in message
oups.com...

Brett A. Thomas wrote:
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

Thanks again!

-BAT


You might want to consider some start buttons to turn it all back on.
They make pushbutton stations that have large "panic" buttons for the
stop button and also include a start. Also, check your codes as to what
gauge wire is going to need to feed your subpanel. See if they will
allow your particular setup.

I have some of those definite purpose contactors and didn't really know
a use for them. Now you have me thinking. I'm not plannning what you're
planning. But, the noggin is smoking. As I've never used one and don't
know their proper wiring, I do have this question. Can several
pushbutton stations operate the same contactor or would there need to
be a series of contactors? I've only wired magnetic starters and one
per machine. I haven't tried to feed a subpanel with them.

I look forward to seeing how this thread progresses when some of the
electrician types get home from work.
Eric T. in MN

ps. Brett, where are you located?

"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



--
If at first you don't succeed, you're not cut out for skydiving

One option is to put Solid State Relays in the feeds to your machines. These
take a very low current to activate (3 - 30vdc at several milliamps each) A
small wall wart can run a bunch of them. You can even run these off of CMOS
chips. Then you can selectively turn on machines as your kids get old enough to
use them. My grandfather did that with me (just with verbal warning) and I
still have 10 fingers.

"TBone" wrote in message
. com...

"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


Just get a good contactor ( about nema #2) and you can put an aux N.O.
contact block on it to perform the "latch" function

William....



--
If at first you don't succeed, you're not cut out for skydiving

"Brett A. Thomas" wrote in message
...
Pounds on Wood wrote:
Sounds like a lot of locks, when the best solution might be a lock on
the
garage/shop door. Kids don't need to be playing unsupervised in a
garage
even if it only houses the family car.

Well, in the short term that's the plan - when they're this age, they
never need to be out there.

I know when I was, say 12, I spent a lot of time relatively unsupervised
in the garage. I don't think they should have to get me to get a
(neander) saw. My *hope* is that, when they're that age, I won't have
to worry about them around power tools, either - I know when I was 12
you couldn't've paid me enough to turn on my Grandfather's radial arm
saw, I thought it was terrifying (even though I'd worked on it with
him). But we won't know for sure until we get there, and there are
always kids' friends who may be over and less intelligent than my own
genius progeny . Whatever the exact age, I expect that there will be
a point when I'm willing to trust them to use neander tools but not
power tools.

-BAT

Good LUCK! When I was about 10 years old my father want to keep me from
running the table saw so he installed a fused switch on it with a paddle
lock on the switch lever.... Thought it was all safe.... Wrong answer:-)
it did not lock the fuse cover, so I just unplugged it ( did not want a
nasty shock:-) and jumpered around the fuse and switch and then plugged it
in to turn it on and unplugged it for off.... BTW I still have all my
fingers!

William.....