COMMUNITY FORUM

masterofnone1

07:58AM | 12/10/07
Member Since: 10/14/07
4 lifetime posts
Bvelectrical
I have a 60 amp Junction box with 13 breakers in it already with two slots still available it is a General electric box wired Hot with no "Main Breaker" The main breaker is in the buddy box I wired from my main house breaker box, so in reality I have two Buddy boxes off my main house breaker box. My question is

Can I wire a Double poll 30 amp Breaker off my general electric Box to Run a Heavy duty Machine that calls for / 230 Volts / 19 amps / 60 Hz / Single phase / to run? Or do I need to wire a 220 volt service? If someone knows the answer and would be so kind as to call me at (919) 681-5558 I am Clinton / I am being pushed to buy this machine or not, it is at a really good price but I do not want to buy something I cannot get wired with what service I have available.

Please help.

Billhart

05:03AM | 12/11/07
Member Since: 04/25/05
1918 lifetime posts
"I have a 60 amp Junction box with 13 breakers in it already with two slots still available it is a General electric box wired Hot with no "Main Breaker" The main breaker is in the buddy box I wired from my main house breaker box, so in reality I have two Buddy boxes off my main house breaker box."

First it is not a junction box, but rather a sub-panel.

And by the way you need to run 4 wires to a sub-panel (2 hots, neutral, and ground) and the neutral bus isolated from the ground bus. On some panels you can do that by just removing a strap. On other you also need to by a ground bus bar kit.

And you did not give any clues of the load on that sub-panel or what is is wired for.

But if you have 2 open slots next to each other then you can install a 2 pole breaker to supply the motor. If the slots are not next to each other then you can rearange the exisitng ones.

If you are questioning the 230 volt requirment the standard supply in the US is 120/240 volts, NOT 110/220.

However, the standard for rating motors is 230 volts. And yes is to works fine on 240 systems.

masterofnone1

05:44AM | 12/11/07
Member Since: 10/14/07
4 lifetime posts
Thank you. I will do as you sugested to my "Subpannel" :o)

TimBonham

10:02AM | 12/11/07
Member Since: 01/09/07
197 lifetime posts
"Can I wire a Double poll 30 amp Breaker off my general electric Box to Run a Heavy duty Machine that calls for / 230 Volts / 19 amps / 60 Hz / Single phase / to run?"

If your motor only needs 19A, I would use a 20A double-pole breaker rather than a 30A one. You can use smaller (cheaper) wires to the motor that way. And if this is a single use circuit just for that motor, there is no need (and it's not a good idea) to provide that much excess capacity. If it shorts out, you want the breaker to blow sooner rather than later.

Billhart

11:29AM | 12/11/07
Member Since: 04/25/05
1918 lifetime posts
Look at the section of code on Motor circuits.

The circuit wiring needs to be rated at least 125% of the operating current.

The motor, it'self is protected by either internal overload protection or protection in the starter.

For a dedicated circuit the circuit overload protection can be much higher than the breaker can be much larger that "normal". I don't have time to look it up, but depending on the typie of overload device it can be 175 or 225% of normal operating current.

Common breakers have a 2 modes for triming. One is a time inverse heating element and bi-metalic trip. The other is a magnetic trip. For "shorts" the magnetic trip will be what protects the wiring and it is near instaneous.

CH and SQ D both show this in the breaker curves.

If this is not a dedicated circuit the 125% rule still holds, but the breaker is limited to the nominal size based on the wire size.

For home workshop these rules are often ignored and it works out OK. Except for air compressors most home workshop motors start with limited load so the starting current and time is fairly low.

They are used on a relatively low duty cycle.

And wiring with modern insulation can care more current than the size of the breaker allows for the #14, 12, 10 sizes.
Click_to_reply_button
Inspiration_banner

INSPIRATION GALLERY



Post a reply as Anonymous

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

Reply_choose_button

captcha
type the code from the image

Anonymous

Post_new_button or Login_button
Register

Few projects are more fun than upcycling a vintage piece in a surprising way. Outfitted with a sink and a delicately tiled... Built on a rocky island in the Drina River, near the town of Bajina Basta, Serbia, this wooden house was cobbled together ... Large steel-framed windows flood the interior of this remodeled Michigan barn with daylight. The owners hired Northworks A... Edging formed with upside-down wine bottles is a refreshing change. Cleverly and artistically involving recycled materials... A Washington State couple called on BC&J Architects to transform their 400-square-foot boathouse into a hub for family bea... Similar to the elevated utensil concept, hanging your pots and pans from a ceiling-mounted rack keeps them nearby and easy... For windows, doors, and mirrors that could use a little definition, the Naples Etched Glass Border adds a decorative flora... The thyme growing between these stepping stones adds a heady fragrance to strolls along this lush, low-maintenance garden ... Decoupage is an easy way to add any paper design to your switch plate, whether it is wallpaper, scrapbook paper, book page... Twine lanterns add pops of crafty—but sophisticated—flair to any outdoor setting. Wrap glue-soaked twine around a balloon ... When securely fastened to a tree or the ceiling of a porch, a pallet and some cushioning make the ideal place to lounge. V... Reluctant to throw away any of those unidentified keys in your junk drawer? Hang them from a few chains attached to a simp... A stripped-down model, sans screened porch, starts out at $79,000. Add the porch, a heated floor for the bath, and all the... Salvaged boards in varying widths and colors make up the dramatic accent wall in this attic space. The high-gloss white of... This garden shed has been decked out to the nines. Designer Orla Kiely created the intimate home for a flower trade show, ...
Follow_banner_a
Newsletter_icon Google_plus Facebook Twitter Pinterest Youtube Rss_icon
 
webapp1