Power Supply Size and Disconnect

[pyrodenis]

Hi All, ..my 1st Post.
This forum looks very helpful...it appears to be a great community.
I just received my BT48 w/ 2.2 HSD spindle. I'm an advanced DIY with long experience in construction management, including commercial/industrial.... wired my own house and a few woodworking shops.
I'm spending some time refreshing my understanding of power supplies, because my electrician is not experienced in tools/industrial and I have some wire I'd like to use.

First, 220v 60amp seems large for the spindle. The controller's 120v, 25a circuit aside, does that 60a include the steppers or something? What about 50a?

Second, although #6 stranded should be enough for that use, I have enough #4 to make 3 runs of the 40' distance (from a 150a sub-panel), and then buy the ground leg. Of course, this would require conduit, a pain, and my shop is in my home. Does the ground need to be #4 also?

Third, using the #4, should I just make it an 80a sub-panel, and take my 120v from there as well?

Fourth, If I decide not to fight the conduit w/ #4, since my shop is in my garage (for now), can I just use #6 NM multi-conductor and save the hassle?

Fifth, is the "fused disconnect" significantly different from a breaker? (Is this a "timed" issue for a motor lock-up or something?)

And now, for my first defiance of the 'keep it simple, stupid rule'..... is there software functionality that could start my dust system with the spindle?

thnx for any help ya'll can lend.

[beacon14]

Welcome, you will get a lot out of this forum and owning your ShopBot.

Be careful asking for electrical advice from strangers though, if you are not sure of what you are doing that is a dangerous area to take chances.

That said, my 2.2HP spindle is on a 30A 220V circuit. There is a separate circuit for the control box. Not sure how the Buddies are wired but 60A does seem like overkill.

If you go with the #4 you will be oversizing the wire, which is generally not a problem except as you realize the hassle of working with such thick wire. You would not need to oversize the ground to match the #4 wire if a smaller wire is all that is really required for the breaker size.

A fused disconnect would be a safety device for instances where the machine is not in sight of the breaker panel. You could pull the disconnect and not worry about someone turning the breaker on while you are working. Not many machines have or need one. In a commercial environment you need a lockable/taggable breaker or disconnect.

I'm not an electrician so this advice may be worth less than what you paid for it.

[Gary Campbell]

Denis...
The only safe route is to call or email ShopBot. They have the exact specs for your machine and will not steer you in the wrong direction.
Gary

[pfulghum]

2.2hp spindle 220V single phase.... PRT ALpha with Indexer...All on a 30A Dedicated Circuit (10ga wire) for 3+ years.. Never had a breaker pop.

[navigator7]

Denis,
I was asking Shopbot about that very thing today. I was told there is a ramp start controller in the control box.
10-20 years ago I don't recall seeing any single phase motors over 1 HP.
As I understand it, once a motor is spinning there is way less amp draw.

[pyrodenis]

This is a PRSAlpha..
Frank, at ShopBot Tech Support, says that if I'm talking about the branch protection breaker, the code requires me to multiply the highest load possible and multiply it by 1.5 ....
Any thoughts on the fuse v. breaker aspect?

[dana_swift]

Denis.. check with a local electrician who knows both the local ordinances, fire requirements, and the National Electrical Code.

My background is electrical engineering, and some of the advice I am hearing on this thread have me squirming.

On fuses and circuit breakers.. both of them come in multiple types. A "typical" circuit breaker will always trip immediately at 3x rating. The ability of the breaker to handle brief overloads during motor start up or lamp ignition, vary with the type.

More info on breakers:

http://en.wikipedia.org/wiki/Circuit_breaker

About the only suggestion I am willing to make is put the spindle on a separate circuit from the bot motion control. Then if the spindle (or some future upgrade) requires unique startup protection, that breaker can be changed independently.

If you are not absolutely sure what to use, call an electrician. Yes it is expensive.

Yes you can do it yourself, but only if you are willing to live with the possible consequences.

Looking forward to posts about the cool stuff you have made! Your fireworks combined with a shopbot made accessories sounds really cool! Fireworks associated with electrical overload is not the kind of post anybody wants to read about...

Keep us posted!

D

[wberminio]

Separate circuits will also isolate any electrical
"noise" that could interfere with the machine's operation.
Dana is right on.Use an electrician.
Maybe you could barter for his work.
That's what i did and it was worth it.

[pyrodenis]

thnx.
I'm not sure if I'll make anything for the fireworks business with the Bot.
It's more for me to transition back to furniture making, woodworking and sculpture, which was my previous life.
D