Got A New Bandsaw

[DC Ross]

So I finally bit the bullet and got a brand-spankin' new Grizzly G0457 bandsaw. The only problem is that I'm an idiot. It comes prewired for 220V operation and can be rewired for 110V, so I figured "Great, I'll just rewire it, plug it in and go", not realizing that it'll be pulling 20A @ 110V. The instructions specify that it requires a 25A circuit and a 5-30 or an L5-30 outlet. Even if I could find either of these outlets, they wouldn't do me much good, since I only have (over-loaded) 15-20A circuits.

So... I'm thinking about installing a subpanel in the garage / shop, which is about 20 feet from the main panel. I have 2 open breaker recepticles in my main panel, so that shouldn't be an issue.

Has anyone done this themselves? Any words of advice? Anything else I should be planning for?

[MescaBug]

Advice? Turn off the breakers before doing any modifications

Just kiddin'. Seriously. A friend of mine had the same problem. He bought a planer, or drum sander I don't remember. Wired it for 110V, but needed 25A to run it. Problem is that the lines coming in the house were 15A only. I didn't talked to him for a while, so I don't know if he did got the machine to work...

I have very limited knowledge about electric components, but make sure you can get enough amps from the main line.

[fryovanni]

Do you happen to have a dedicated circuit feeding an outlet in your garage(sometimes we would install these for freezers)? You may be able to convert a dedicated circuit to 220v., but you HAVE to be ABSOLUTELY sure it is a dedicated circuit that only feeds that one device and is connected to nothing else. Your best bet is going to be to bring in a 220v. circuit (current will be less, voltage drop will be lower, and this is really important when starting a motor(this is why they are wired for 220). If your running a new circuit make it 220. If the full load amps at 110 are 20, you should size your breaker to accomodate the inrush current (a 40 amp breaker would be more appropriate). Depending on the distance the circuit needs to run from your panel to the equipment, you should oversize the conductors so you won't have voltage drop problems, and at 110 volts you can't go very far before you have 3% voltage drop. At startup the motor will draw a lot more current(higher current and all else equal *size of conductors & length of conductor= higher voltage drop), if the voltage drops below the motors tolerance it will simply not be able to start turning.

Peace,Rich

[Quarter]

If you are going to bring in a new circuit, definitely go 220.

Unless you have some experience, I'd strongly recommend getting a qualified electrician to help.

[MescaBug]

Make sure the wiring for the new circuit is big enough for 25A. If not, you will have a nice fireworks in your walls, and that means a call to your insurance company.

And make sure your main breaker can accomodate the extra amps drained by the new circuit.

Example: If you have 6 15A breakers, your panel is probably rated at 100A. Maybe a little more. 6X15A + 25A = 115A. Busted.

[Prostheta]

Heh. So if you're going to use your hellaciously powerful new bandsaw, turn off the TV, the music, all your amps, the freezer and more importantly the LIGHTS.

[fryovanni]

It is a good idea to look at your panel and consider the new load you are placing on it. The actual load that this motor adds to the panel is less than what many people would plug into a wall receptacles without hesitation (say a couple space heaters or turning on your microwave and a toaster at the same time). A house panel should have a main device that would protect the panel from drawing more power than it can handle(old breakers that may not function properly, panels with loose connections and so forth are of course a potential problem with or without this added load). It is worth thinking about your service and equipment. If you have an older service often times there can be neglect or sizing based on demands that are not up to todays usage, it is not a bad idea to have an electrician check out the service.

As far as the calculation

Example: If you have 6 15A breakers, your panel is probably rated at 100A. Maybe a little more. 6X15A + 25A = 115A. Busted

. That is not how the load for panels would be calculated. Branch circuit breakers often have more capacity(if you add them up) than the main breaker. The branch breakers are sized to protect the branch circuit wiring, and possibly dedicated equipment that is served. The load applied to a panel is calculated by connected load, allowances per. square foot of space, and these loads are adjusted based on diversity factors.

Sizing on a motor circuit like this is unique to other types of loads in that the breaker is not sized to carry the FLA (running amps of the motor), but is allowed to be adjusted higher to accomodate the inrush current so the motor can start. The conductors that feed that motor circuit are sized to the FLA of the motor, with consideration for voltage drop(as should be the case with any circuit). If a load is to be considered continuous (runs 3 hours or more) than the load should be figured at 125% (breaker still being sized based on FLA inceased to a max of 250% for inverse time breakers or 175% for dual element time delay fuses).

Peace,Rich

[MescaBug]

Thanks for the clarifying. This is not what I was told, and this is not how I wired my shop... But it works, so I assume everything's under control

Edited January 30, 2008 by MescaBug

[fryovanni]

Thanks for the clarifying. This is not what I was told, and this is not how I wired my shop... But it works, so I assume everything's under control

If you wired a shop (note; I was refering to a house-residential loading) the way you summerize the load calcs are a bit different. Dedicated loads for a shop(specific equipment) are going to be calculated differently than a residence (diversity factors are different). There is nothing that really makes it clear as to whether all the equipment will be utalized at the same time. If it is run for more than 3 hours it is added to the load at 125% of its value otherwise it is 100%, you would take heating and cooling compair loads and since only one will operate at a time you take the larger of the two, take your lighting load at 125% since it will be on for more than 3 hours typically, non-specific general receptacles would be taken at 180 volt amps each, and what have you to generate the demanded load on that panel (which is what you size to). Most of the breakers used are not rated to carry the full rated load continously(3hrs+), so you have to limit loading to 80% of the rated load(no more than 16 amps on a 20 amp breaker for instance). Anywhoo.... I am really typing too much here, and am not really trying to explain the calcs fully, just that a shop is calculated differently than a residence. NEC Article 220 gives service and branch circuit calculation information, NEC Article 430 deals with motors. Since most home owners have the legal right to do electrical work on their property, The NEC(as well as any state or local code amendments) is a good book to have when you want to do some research.

Peace,Rich

[Woodenspoke]

Thanks for the clarifying. This is not what I was told, and this is not how I wired my shop... But it works, so I assume everything's under control

If you wired a shop (note; I was refering to a house-residential loading) the way you summerize the load calcs are a bit different. Dedicated loads for a shop(specific equipment) are going to be calculated differently than a residence (diversity factors are different). There is nothing that really makes it clear as to whether all the equipment will be utalized at the same time. If it is run for more than 3 hours it is added to the load at 125% of its value otherwise it is 100%, you would take heating and cooling compair loads and since only one will operate at a time you take the larger of the two, take your lighting load at 125% since it will be on for more than 3 hours typically, non-specific general receptacles would be taken at 180 volt amps each, and what have you to generate the demanded load on that panel (which is what you size to). Most of the breakers used are not rated to carry the full rated load continously(3hrs+), so you have to limit loading to 80% of the rated load(no more than 16 amps on a 20 amp breaker for instance). Anywhoo.... I am really typing too much here, and am not really trying to explain the calcs fully, just that a shop is calculated differently than a residence. NEC Article 220 gives service and branch circuit calculation information, NEC Article 430 deals with motors. Since most home owners have the legal right to do electrical work on their property, The NEC(as well as any state or local code amendments) is a good book to have when you want to do some research.

Peace,Rich

My eye balls just popped, sorry rich most home owners just add the wiring they need with out looking at code but if you are not intending to sell your home or have the inspector in then "what happens in the shop stays in the shop".

If you have no space on your panel and you have no fear with putting in a 220v circuit in then do this, Purchase two split breakers at what ever amps you want 15 or 20 and move 4 single lines onto these two split breakers. This opens two slots to add a dedicated 220V breaker to the panel. You don't want a 220 volt connector that does not have the breakers attached so both trip together. Now some places don't allow split breakers but your home depot probably sells them any way. For 220v remember you need two side by side slots in the panel you cant just spit a single slot (2 phase=2 slots). If your outside line capacity is 200 amps you should be fine, no one turns everything on in there home at one time. Just make sure you do have 2 phase coming into your home first, any 220v breaker in your box is a yes. Each state and within each state township the rules change no matter what the national code is. If you move take it out. Remember to buy the right breakers for your box.

The other thing is to just change the plugs out for a standard 110 outlet and change the breaker on that line to 20 amps and cross your fingers.

Edited January 31, 2008 by Woodenspoke

[fryovanni]

My eye balls just popped, sorry rich most home owners just add the wiring they need with out looking at code but if you are not intending to sell your home or have the inspector in then "what happens in the shop stays in the shop".

Hahaha, Sorry WoodenSpoke. I know most people don't permit something like this. I was going to just make a couple suggestions about the circuit itself, but no idea why I let myself babble about load calcs (bad habit of mine, get off the subject and yap). You would think after doing Electrical work for about 20 years it would be the last thing I would want to talk about. To tell you the truth I have even run an SO cord off my disconnect for my AC(20 amp 240v Ckt) to power up tools (temp. not permenant), I just made sure to not turn both on at the same time.

Peace,Rich

[MiKro]

So I finally bit the bullet and got a brand-spankin' new Grizzly G0457 bandsaw. The only problem is that I'm an idiot. It comes prewired for 220V operation and can be rewired for 110V, so I figured "Great, I'll just rewire it, plug it in and go", not realizing that it'll be pulling 20A @ 110V. The instructions specify that it requires a 25A circuit and a 5-30 or an L5-30 outlet. Even if I could find either of these outlets, they wouldn't do me much good, since I only have (over-loaded) 15-20A circuits.

So... I'm thinking about installing a subpanel in the garage / shop, which is about 20 feet from the main panel. I have 2 open breaker recepticles in my main panel, so that shouldn't be an issue.

Has anyone done this themselves? Any words of advice? Anything else I should be planning for?

First off if you are not sure then have professional do it. I own a Construction and Remodelling company and very aware of electrical needs but I will not put myself at liability advising you HOW to take this on and anyone here that does is acting FOOLISHLY in todays litigious society.

AGAIN I cannot over emphasize the need for a professional if you are not sure what to do, if not ,then at least talk with your City electrical engineer. They will help you make the right decision if you ask.

YOU may want to ask this question at a different forum. I would suggest the Breaktime forum at

link

Just some friendly advice from someone that cares about your health and safety

Mike

Edited January 31, 2008 by MiKro

[Woodenspoke]

]

First off if you are not sure then have professional do it. I own a Construction and Remodelling company and very aware of electrical needs but I will not put myself at liability advising you HOW to take this on and anyone here that does is acting FOOLISHLY in todays litigious society.

AGAIN I cannot over emphasize the need for a professional if you are not sure what to do, if not ,then at least talk with your City electrical engineer. They will help you make the right decision if you ask.

YOU may want to ask this question at a different forum. I would suggest the Breaktime forum at

link

Just some friendly advice from someone that cares about your health and safety

Mike

I'm not a rocket scientist but I have tinkered with wiring as non professional. I think as long as you follow the existing wiring in the house (I am going to assume it is a newer home with Romex plastic sheathed wire). you should be OK. But if you have any doubts then do not do it as Mike said. But on the other hand all the poor people who have to use pine for body wood is an indication money is an issue with most forum members.

But even a regular Joe can go as far as doing their own work legally if you wish to have the township accept plans and inspect your work. I for one have had to go this route. In a large in ground pool installation the pool electrical guy saw the soil conditions and bailed on me. It was bad enough to have to rent a small back hoe. A local guy wanted 10 X's as much. The rewire was done to the highest degree because I did it myself. Included 2 breaker panels and lots of in-ground outdoor pipe. Needless to say everything passed and I saved money over the original contractor and I got twice the bang for the same buck. I now have a half empty sub panel in my basement. He also saw the whole box on his inspection and didn't comment on all the additional shop wiring I put in long before the pool. Anyone want to buy a 1 1/4" pipe bender LoL.

Again your results may vary depending on your experiences. I happen to have been a contractor at various points in my life so I was not clueless. It certainly is easier than building a guitar. You can also buy a book?