220 V table saws and ground

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Substituting a standard 130V bulb for a standard 120V one probably does *NOT* pay for itself -- *IF* you need the same light output as the 120V bulb gives.
Running a bulb at lower than the 'rated' voltage, _does_ extend the life of the bulb, *BUT* the quantity of light output (the 'lumens') goes down even _faster_ than the savings in electricity. Thus the 'cost per lumen' of the eletricity is _higher_ usuwing the 130V bulb at 120v, vs the 120v bulb.
It is also a fact that the cost of electricity over the life of the bulb swamps the cost of the bulb itself.
That said, there are "much more efficient" technologies for lighting than 'incandescent', e.g. 'halogen'. These technologies have a _much_ higher lumen output _per_watt_of_power_consumed_ than conventional incandescents. Thus, you can get the same _light_ output, for far less power consumed. Amortized over the rated life of the bulb, the power savings _greatly_ exceed the cost of the 'high-priced' bulb required to achieve the savings.o
Running the _same_ technology (incandescent) in a down-graded form (130V bulb at 120V) does *not* achieve these savings. In fact, because the bulb is being operated in a 'less than optimum' (relative to _design_ criteria) manner, the cost _per_lumen_output_ is higher than the optimal operation.
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Since there's been a lot of great thought posted here about voltage, resistance, light output and longevity, I thought I'd go ahead and give a general explanation of electricity for those of you all who don't really understand it fully. It's a repeat of a post to another newsgroup, but of equal relevance here. <Grin>
Electricity explained I think its time for me to explain about 220 current and why it is so different from 110 volt service. First of all, it's twice as big. Secondly, it'll shock you more. Outside of that, 220 is really two 110 volt lines coming to your house from different parts of the globe. The up and down 110 comes from the northern hemisphere, and the down and up version comes from below the equator. Without trying to get technical, it all boils down to the direction water flows when it goes down the drain. On the top of the earth, it goes clockwise, while on the bottom of the earth it goes counter clockwise. Since most electricity is made from hydro dams, the clockwise flow gives you an up and down sine wave, while the counterclockwise version gives you a down and up sine wave. Between the two, you have 220 volts, while either individual side only gives you 110 volts. This is particularly important to know when buying power tools- which side of the globe did they come from? If you get an Australian saw, for instance, it will turn backwards if connected to a US generated 110 volt source. Sure, you can buy backwards blades for it, but that is an unnecessary burden. Other appliances, like toasters cannot be converted from Australian electricity to American electricity, with horrible results. I knew one person who bought an Australian toaster by mistake and it froze the slices of bread she put in it. If you wire your shop with 220 and accidentally get two US-generated 110 volt lines run in by accident, you can get 220 by using a trick I learned from an old electrician. Just put each source into its own fuse box and then turn one of the boxes upside down. That'll invert one of the two up and down sine waves to down and up, giving you 220. DO NOT just turn the box sideways, since that'll give you 165 volts and you'll be limited to just using Canadian tools with it.
--
Nonny

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Nonny wrote:

ROTFL! ... should be in the Anti-FAQ.
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Nonny wrote:

:-0
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wrote in message

Robert, You know that's a bunch of bull. If you have an Australian saw and it runs backwards all you have to do is to mount the blade backwards. Sheesh.
Max
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One minor detail -- *I* didn't write _that_ bull. Nonny did. He left in the "Robert Bonomi.. wrote", while taking out everything I'd said in my posting.
That said, when _I_ am in Australia, I just mount the saw to the ceiling, and everything runs in the proper direction for me.
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wrote in

That's ridiculous, you'd get sawdust in your hair. <grin> Sorry for not clearing out the attribution properly.
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Nonny

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By using 130V bulbs on 120 V, he's paying *MORE*PER*LUMEN* for the electricity to operate them, vs a 120V rated bulb.
Generally people thing of a light bulb as 'a light bulb', with little regard to how much light it puts out. This leads to ill-informed decisions about the cost-effectiveness of various alternatives.
The _first_ thing one has to do, is figure out how much _light_ is needed and/or desirable, then look for the 'least cost' way of getting that amount of light. Higher wattage bulbs produce more light output _per_watt_ than low wattage ones. Thus, a few higher wattage bulbs will produce more light than an equivalent wattage of low-wattage bulbs.
The true 'cost of ownership' of light bulbs depends on the cost of the bulb, the frequency with which it has to be replaced, the 'cost' (labor, etc) in performing the replacement, _and_ the 'operating cost' (the electricity to drive it).
The cost of the electricity -- over the lifetime of the bulb -- generally swamps the cost of the bulb itself.
The frequency of replacement determines how much of a factor the 'cost of replacement' is. Depending on circumstances, this can be a 'small change' item, or it can be far more than the bulb _and_ the electricity to run it.
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They are called 'swinging transformers' - like swinging chokes.
The contact sets make before break - creating a shorted turn(s) that causes a little change in state. If the contacts get pitted, then all sorts of great voltage spiking occurs. That is when you call the power company and state that when the a.m. stoves turn on or afternoon heat forced air on - and it goes crazy - they know what to look for. In their load station yard.
We had one get so bad that by the time I returned from overseas it had almost eaten itself up. I put a drantz (IIRC) meter on it to measure the spikes and gave the tape to the power company. A new transformer was hauled in. It had eaten most of the sliding contact off and made it non-repairable.
Some smaller co-ops up the voltage so when a brown out occurs it isn't out of spec - just below normal.
Martin
CW wrote:

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Funny, in the business we always called them tap changers, as did the power companies that we dealt with (nation wide in the U.S.and parts of Canada). When dealing with the manufacturers, they called them tap changers too. Glad you straitened that out. We must have been wrong all these years. I'll have to let them know.
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Loss of one hot at the breaker panel can also be entertaining, although generally not as destructive. I've had that happen once or twice, mainly at a house with an older distribution panel that used individual cartridge fuses for the main rather than a ganged circuit breaker. Have one wear out or go pop or whatever, and suddenly you have one phase powered normally, and one phase powered through any 220V things that happen to be on--mainly the water heater, in my case. Small loads worked fine on that leg, but anything that drew any current would cause the voltage to go down dramatically. The microwave clock, for instance, ran fine, until actual cooking was attempted....

It depends where you're talking about checking. There is one point in the system, typically at the main disconnect (the main breaker box), where neutral and ground are bonded together, and at that point the neutral buss is the ground buss and vice-versa.
For separate outbuildings, I think (but I'm not sure about this, not being an electrician) the usual practice is to have a separate ground rod and bond that to the neutral bus at the outbuilding's main panel, omitting a separate safety ground wire between the buildings. In other words, the outbuilding is wired as though it were an isolated installation, not as a subpanel in the main building. In this case, for the main panel in the outbuilding, neutral and ground would again share the same bus bar(s). Any difference in ground potential between the house ground and the outbuilding ground would, of course, result in a current flow over the neutral wire; the assumption, I guess, is that there shouldn't be a large potential difference and hence not too great of a current flow.
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Andrew Erickson

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Andrew Erickson wrote: ...

At the box that has the breaker for the circuit in question, obviously...
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Do any of you electricians recall the OLD way of wiring a double pole switch from the knob and tube days. Yup, fellows, there actually is an alternate way to wire a DP circuit.
Nonny
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Nonny

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Nonny wrote:

http://www.homeimprovementweb.com/information/how-to/three-way-switch.htm
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On Tue, 8 Dec 2009 14:08:38 -0800, the infamous "Nonny"

I had K&T in my old 1939 house in Vista, CA. When I rmodeled the front bathroom, the tubafores behind that 1/4" plywood all measured exactly 2" by 4", in roughsawn redwood, too.
I hated wiring anything extra into that home...
-- To know what you prefer instead of humbly saying Amen to what the world tells you you ought to prefer, is to have kept your soul alive. -- Robert Louis Stevenson
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My Dad bought an older home and built a detached 2-car garage around 1950 or so. I vaguely remember when the garage was being built and watching the electrician wire it for a single light and one plug, controlled from a switch both at the house and at the garage/
As a teen, later on, I bought a little booket at Sears, called, "How to wire a house," which I thought was an incredible insight into the secrets of wiring. However, something never made sense to me until later on, when I was wiring homes myself as a means to continue college. There were only two wires running between the house and garage. It finally dawned on me why in the summer, the light wasn't as bright and why it would dim so much when I'd plug a drill or small saw into the duplex receptacle.
I investigated and for the first time, noticed the bare wire running from the old switch down to a rod driven into the ground. That was the light leg and when it was summer in MO, it was usually dry. The electrician had saved probably $2 in wire, back then, deciding instead to use the earth as a ground/neutral.
--
Nonny

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Code... hmmmmm. Naw there was no ground at all in the box that I spliced into. ;~) The dryer and shop share the same circuit. If I ever move I will yank the external addition.
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Leon wrote: ...

I bet there is...(a ground that is)... :)
If it's 3-wire dryer outlet the "neutral" will actually be on the ground connection conductor...so when you tied your third to it it is also ground. I'd wager that's what you'd find if you were to check the circuit connections in the panel.
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You are probably right.
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Neutral is connected to an earth ground at the service panel but the neutral and ground wires play different roles in the circuits once you leave the main panel. The neutral carries current. It s nominally the return path, but because we use AC, the current flows in both directions at different times. The ground should never carry current in normal situations. It is there for protection.
In a three wire 220v set up, you have two hot wires and a ground. The two hot lines are in opposite phase, giving the 220v volts.
If you are re-wiring a tool to run on 220, you should also change the plug to one rate for 220. They have a different prong pattern so you can't easily plug them into the wrong circuit.
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