Electrical help: 20 amp vs 30 amp

"Neutral" can be a very confusing term.

Rather than neutral, think of it as an "above ground return".

It can be a current carrying conductor and should be treated as such.

"Earth Ground", usually the green wire in the electrical world, is a totally different issue.

HTH

Lew

Reply to
Lew Hodgett
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If you're confused by the term "neutral", hire an electrician.

Using the word "ground" to describe the center tap of a transformer is misleading. It is the neutral tap of a multi-tap transformer. It is grounded at some point, but it is not ground, nor is it a "return".

Reply to
DJ Delorie

Could probably find one of my students.

Go back and reread the post. After that go back and enroll again in EE101, the power option.

Lew

Reply to
Lew Hodgett

I think you are thinking that the circuit breaker protects the item powered by the circuit. This is not the case. The breaker or fuse protects the wire from being overloaded, not the device. Quite common to plug a 60 watt lamp into a 20 amp circuit. If the lamp developed a short to ground it would hit 20 amps in a big hurry.

On a saw, if you were trying to cut through some nasty gnarly sappy wood with a dull blade mounted backwards the thermal cutout would pop to protect the windings on the motor long before it would pop the breaker.

Reply to
Roger Shoaf

Or the guys who wired my house :-P

Sorry, already have an EE degree. I even know how to make transformers from scratch.

Reply to
DJ Delorie

Reply to
neal.don

I'd just like to thank everyone again. The saw now has power.

I left the 30 amp breaker. Bought a single outlet rated 20 amps/240 v and a matching plug. It is dedicated to the saw (nothing else can/will be plugged into it).

It's a bitch working with that 10 g wire though.

The 1023 SL is just humming right along! I haven't put a blade in it yet - still fiddling with the wings & fence. I want to try to get everything as perfect as I can from the get-go.

Lou

Reply to
loutent

You also should not post in electrical threads. The amount of current draw in a circuit has ABSOLUTELY NOTHING to do with whether a circuit "needs" a neurtral or not.

Neutrals are a part of a 120V circuit. They are not an electrically necessary part of a 240V circuit.

A "case ground", as you and no one else would put it, has been a requirement for a long time, but as a safety item; it is not electrically necessary.

- - LRod

Master Woodbutcher and seasoned termite

Shamelessly whoring my website since 1999

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Reply to
LRod

I always thought you made transformers from copper and iron :-)

Reply to
Roy Smith

You buy enough copper you'll need plenty of scratch.

- - LRod

Master Woodbutcher and seasoned termite

Shamelessly whoring my website since 1999

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Reply to
LRod

Man, if the OP thinks he had confilicting advice last time, what is he going to think now?

Reply to
Lawrence Wasserman

A 20 amp two pole breaker is worth about 15 bucks. Although I agree in principle that the system will run fine on the 30 amp circuit, I wonder whether your warranty would still hold if something happened. The internal wiring and switches on their machine will not be of adequate gauge for 30 amps of current, so if a wiring fault occurs in the saw, the risks may be higher. Sure, Grizz should have designed the system to internally trip with excess current. Also, the resistance and design of the motor should automatically limit the amperage of the circuit. However, suppose that you started a fire caused by excessive current, and your house burned down. Would Grizz be expected to pay? In the owner's manual they say that they want a 20 amp circuit, period. I suspect they don't say 'minimum 20 amp circuit'. So their lawyers could argue that you made a mistake. If you blow the motor and Grizz find out that 30 amps were running through the wires, they might find cause to contest your claim. Changing the breaker is a one-minute job, and you can then say that you followed the owner's manual to the letter. You can always change the breaker back to 30 amp later, if you wired it as a 30 amp circuit. Cheap insurance.

Dave

"loutent" wrote in message news:090120051434165364% snipped-for-privacy@no.net...

Reply to
Dave

Oh, Dave - A BIG Thank You!

After reading your post and realizing the risks I've been taking with all those 60 watt lamps and 1/10th watt alarm clocks plugged into those humongous 15 and 20 amp circuits, I've rushed breathessly around the house and unplugged them all! Gawd only knows the risks we all take on a regular basis by plugging under-utilizing dangerous equipment into over rated outlets!!!

Thanks again for saving me from disaster with my insurance company!

In eternal debt to you,

- Doug

Reply to
Doug Winterburn

Dear Doug,

Thankyou for your facetious comment, which I anticipated from someone. Those appliances are all rated to be plugged into 15/20 amp 110v AC outlets. So of course the manufacturers design those appliances with that point in mind, and with appropriate safeguards to protect consumers based on that maximum amperage the appliance could be subject to. However this table saw is designed to be plugged into a 20 amp circuit. Sure, I think it will work fine on a 30 amp circuit, provided there is no short circuit or higher than anticipated draw. I do wonder why Grizz didn't just say that it will work fine with 30 or even 50 amp breakers. But it didn't, maybe for reasons of liability.... Therefore this analogy that you are making is not an accurate comparison.

Dave

Reply to
Dave

Dear Dave,

Breakers are designed to protect the wiring to the load, not the load. All modern motors (load) have thermal breakers integrated to protect the motor.

Your friend,

- Doug

Reply to
Doug Winterburn

As I said before:

Please. You should refrain from offering electrical advice. I'm sorry if that hurts your feelings, but your reply does not reflect the slightest bit of reality with regard to electrical theory, engineering, or legal requirements.

- - LRod

Master Woodbutcher and seasoned termite

Shamelessly whoring my website since 1999

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Reply to
LRod

...A bunch of stuff...

Dave, you're way off here. Breakers are sized for the ampacity of the circuit wiring. As long as the load on the circuit is within the rating, it's just fine and will do it's job as designed. There's no protection for the device itself (in this case the saw) implied by the breaker, simply the protection from overcurrent so that the household wiring does not overheat.

Reply to
Duane Bozarth

The Grizzly saw hookup originally asked about is a 3 wire hookup to the electrical switch. Hot-Hot-Neutral. If the wire has a white jacket on it, it is a neutral. Ground wires are bare.

Beyond that, if you open up your main service panel to your house, there SHOULD be a little green screw run through one edge of the NEUTRAL bar that connects to the back of the service panel, which in turn is connected to the GROUND bar in the service panel. That said in the main service panel there is a completed circuit between neutral and ground in a 4 wire hookup. In sub-panels, the "green screw" is removed and the 4 wires (hot-hot-neutral-ground) are run separately to the main service panel. It's just a formality done so that an electrician can tell it is a sub panel, since back at the main panel the ground and neutral are combined...see above. This is according to current NEC code.

So, the whole neutral or ground argument is mute...they connect together back at the panel. Therefore, if it's got a white jacket, call it neutral, if it's bare, call it a ground.

Kev>>

Reply to
Kevin Matthews

Just a formality? Like Dave, above, you should not be giving electrical advice.

While you may have actually looked at the code, you _clearly_ didn't understand it.

You couldn't be more wrong.

scott

Reply to
Scott Lurndal

...

The word you were looking for is moot. It's too bad you chose to not be mute.

Reply to
Duane Bozarth

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