240V disconnect with 120V lathe

Hi all,
I have a 240V fused disconnect that I would like to use on a 120V lathe. The disconnect has holders for two cartridge fuses, one each for the 2 hots of your normal 240V circuit. If I used it for my 120V lathe I could either run hot AND the neutral thru separate fuses (which I wonder whether is a good idea) OR I could just run the hot thru a fuse and leave the neutral continuous. What would be best? Consider also I get a lot of lightning. I thought maybe running neutral thru the fuse would be extra protection if lightning came up thru the neutral. (I'm running the equipment ground continuous of course, not fused.)
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On 1/29/2012 12:27 PM, snipped-for-privacy@hotmail.com wrote: ...

...
The neutral may _not_ be fused by NEC so the question re: lightning is moot (besides not being useful anyway).
--
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As others have said, do not fuse the neutral. Its connection is never broken by anything that does not disconnect the hot wire also.
Run the hot wire through the fuze and connect the neutral direct without going through a switch on the disconnect.
If worried about lightning, put a plug on it and unplug when not in use.
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On Sun, 29 Jan 2012 15:06:01 -0500, "Ralph Mowery"

Here I was ASSuming the 240 disconect was already connected -
If it is just a 240 disconnect sitting on the shelf and he wants to use it as a disconnect for 120, it is a totally different situation. Use one side (L1 or L2) and neutral and leave the opposite line connection disconnected.
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Heh,fuse the neutral,and if the neutral fuse fails but not the hot fuse,then your powered device becomes HOT,with NO indication of it. Touch it and any ground,and you fry.
--
Jim Yanik
jyanik
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On Sun, 29 Jan 2012 10:27:52 -0800 (PST), snipped-for-privacy@hotmail.com wrote:

Common practice is to wire a 220 cord to dual gang (square) utility box and connect 2 duplex 115 outlets in the box, on connected to each "line" and sharing the neutral. Gives you what the guys on the list call an "edison circuit" or what we up here in Canada call a "split".
Plug the 220 appliance cord into the 220 plug and "Bob's your uncle".
Same can be done hard-wired, of course - but the plug-in adapter does not require a permit or inspection and is legal for you to do in ANY jurisdiction. If the cartrige fuses are overfusing the downsteam wiring, install a fuse or breaker in the "pigtail", using a bigger box.
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On 1/29/2012 10:27 AM, snipped-for-privacy@hotmail.com wrote:

Change out the motor for a 240 unit or get a step-down transformer with suitable capacity.
Paul
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On Sun, 29 Jan 2012 11:51:10 -0800, Paul Drahn

Boy, THAT is a waste of effort and resources on an American 240/120 circuit.
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wrote:

It never ceases to amaze me how some people can not read for comprehension.........
To the OP, yes you can use this box without any problems, but only use one fuse and only swtich the hot lead (should be the black wire). The neutral (white wire) is continuous. Just wirenut the two white wires in that box. The green ground wire is also continuous, but really should be grounded to the box. There should be a ground screw in there to use, and put both green wires to that screw (or pigtain a short piece of wire from the box, and use a wirenut on all 3 wires).
Be sure to check the current (Amps) of the motor and use a suitable gauge wire, and fuse accordingly. (Of course the wall outlet also needs a breaker suitable to handle the lathe). If this is a common home lathe, a 15A circuit should do the job, which would mean #14 gauge wire for the power cord (or larger, which would mean a #12 wire) [The smaller the number, the thicker the wire].
Fuses rarely do any good to stop lightning. Lightning rarely comes in the neutral, since the neutral on the pole is connected to ground rods. A lighting supressor would be more helpful. These can be purchased to be wired into a breaker panel, and thus could be used on your tool, but I'd put it right into your breaker panel for the whole home instead.
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On 1/29/2012 1:27 PM, snipped-for-privacy@hotmail.com wrote:

Assuming you're using this disconnect because you have it laying around, just fuse the hot leg.
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The only mistake I made in the original post is, I will attach the equipment ground to the ground lugs on the disconnect box.
Yes, this is a box I have kicking around. Lessons learned: do NOT fuse neutral, fuses don't mitigate lightning.
My original problem was, the lathe does not have an on/off switch, just a plug. I dislike leaving it plugged in all the time because of lightning, and I want a more convenient way to switch it on. Thought this was the proper way to do it, except with a 120V disconnect, which is harder to find. Maybe this is just a waste of effort like one of the posters said. How about just wiring the lathe on a residential 20A wall switch?
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On Jan 30, 10:43am, snipped-for-privacy@hotmail.com wrote:

The motor is 2hp BTW.
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On Mon, 30 Jan 2012 07:44:36 -0800 (PST), snipped-for-privacy@hotmail.com wrote:

A 2HP 120 volt motor should REALLY be on a 20 amp circuit.
What kind of plug is on it? How big is this lathe? Wood lathe or scre-cutting/machinist lathe?
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On 1/30/2012 9:44 AM, snipped-for-privacy@hotmail.com wrote:

It would be pretty likely a 2 hp motor would be dual-voltage.
2 hp @120V would possibly be drawing 22-25 A which is marginal at best on 20 A circuit.
I'd suggest the better thing is to
a) Convert it to 240 V (halving the current draw), and
b) Add a switch to the device itself.
As for the lightning concern, the likelihood of it being the target of anything bad is quite low in comparison to things like electronics, a fridge in restart mode at the time, etc., etc., etc., ... A plain ol' 'lectric motor on its own is pretty robust.
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Whoa! You're intending to switch it with a disconnect?
We did that in the plant where I worked, long story, had to do with zero energy state regulations. Big mistake. Disconnects are NOT designed for that kind of service and they will fail, sometimes spectacularly.
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wrote:

It is done a LOT. Not for high currect stuff, but up to 30 amps if it is a snap action disconnect. A straight old knife switch is not so good for that application.
My lathe has a drum reversing switch with center off, as well as a normal toggle style switch.
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In homedepot it's less than 5$ so connect hot to disconnect and netral and ground do not. Later on when you switch to 240v solar panels connect L2 to that cheap box. :)))
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