03:16PM | 10/19/09
Member Since: 10/18/09
3 lifetime posts
Im confused with the formula-

Watts / volts = amps

Im running a wire from my one room to fuse box. Its going to be #10/2 wire on a 30 amp breaker. The equipment can be powered by 120v or 240v by simply changing the powercord, which has 3 prongs for the 240v. My equipment is 3000 watts and im almost possitive its 33 amps total. The equipment will run for about 8 hrs a day. My question is with the formula. Since im going with a 240v will it bring the total amps to 12.5 instead of the 33amps. 3000w/240v = 12.5amps. and then my 240v 30 amp breaker will be fine or do i have to go with 240v 8/2 gauge wire 40 amp breaker. thank you so much for your time and input.


07:54AM | 10/20/09
Member Since: 03/31/05
265 lifetime posts
And you would have to do more than just change the power cord.

3000W/240V=12.5A is correct. If it will run for more than 3 hours, then you apply a 1.25 factor bringing the amperage to 15.6. This could be wired using 12ga and a 20A breaker.


09:33AM | 10/20/09
Member Since: 07/22/04
630 lifetime posts
doesn't that make a difference also?


03:39AM | 10/21/09
Member Since: 10/18/09
3 lifetime posts
Thanks for the quick response. The distance from the room to fuse box is approx 50 ft of wire. I bought 10/2 gauge wire and a double 30amp breaker. The equipment is 3 1000 watt Quantum ballast(H.I.D Lighting). The equipment if im not mistaken will run for 8hrs a day. And with these ballasts there is a optional cord for 120v and 240v im going with the 240v both plugs are included for either 120v or 240v. Im still getting told that i have to run 10/2 and others are saying 10/3. I just want to make sure i install the right gauge wire so my electrician can just hook it up at box. I will return the breaker and 10/2 wire if need be.


06:29AM | 10/21/09
Member Since: 03/31/05
265 lifetime posts
If these are straight 240V lights (and they should be) you need 10/2 with ground not 10/3.

I'm almost afraid to ask what you might be doing with that kind of lighting in a residential setting.

Of course, if it is not residential, then you should not be doing any wiring there unless you are licensed, and if you were, you wouldn't be here.


03:16AM | 10/22/09
Member Since: 10/18/09
3 lifetime posts
im just gonna go on the safe side and go with 8/2 with ground black wire white wire and bare ground on 40 amp breaker 240v. thanks for all your responses and hopefully this keeps my wife busy for a few hrs a day.


Post a reply as Anonymous

Photo must be in JPG, GIF or PNG format and less than 5MB.



Post_new_button or Login_button

To test the boundaries of small-footprint living, interior designer Jessica Helgerson moved her family to a 540-square-foo... Filling an underutilized area beneath the stairs is a smart way to save space. Doing so with a stash of wood, however, is ... The Audubon Society inspired wallpaper in this Adirondack-styled mudroom will get you in the outdoor mood. Grab your coat ... Chalkboard paint opens up endless possibilities for customizing your dresser time and time again. Use chalk to label the c... A fireplace in the bathroom creates the ultimate setting for relaxation. Homeowners often choose electric or gas over wood... This roomy boot tray made from punched metal stands up to all the elements. Station it in your mudroom or at your back doo... There’s nothing like a new set of cabinet hardware to refresh a room. The possibilities are endless: Go modern, rustic, or... FLOR tiles are an affordable way to customize a carpeted floor covering for any space. Make anything from runners to wall-... Chalkboard paint features prominently in this elegant yet unpretentious headboard design. Add a new message daily to reflec... Salvaged boards in varying widths and colors make up the dramatic accent wall in this attic space. The high-gloss white of... The indecisive homeowner need not fret over choosing one (or even two) cabinet colors. The kitchen cabinets in this artist... Incorporate nature into your lighting scheme by securing a dead tree in a concrete mold and draping your pendant lamp from... Simple and striking, a couple of pieces of "lovingly used" furniture creates a special kind of charm. A weathered chair fo... First dress up your metal shelves with a coat of paint in an accent color that complements your kitchen decor. Then arrang... Dark wood shelving and a matching upholstered bench keep this closet sleek and refined. The large window brightens the sub...
Newsletter_icon Flipboard-glossy Facebook Twitter Pinterest Youtube Rss_icon