Used SawStop


Mark J

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  • 2 weeks later...

That looks great, but I gotta ask; didn't you have a real electrician install the receptacles? If so, why would he have labeled them 220V? Any real electrician knows that is not a thing & hasn't been in the time just about anyone on this forum has been alive. Sorry, pet peeve of mine.

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@drzaius, why is it such a peeve? I work in an industrial facility, dealing with AC power distribution, at (rated) voltage levels of 161kv, 33 kv, 4160 v, 480 v, 240 v and 120 v. 

None of them ever MEASURE at the rated level.  Although the incoming line measures 167 kv (not 161), system impedance and load results in a wall socket voltage closer to 110 v (or less) than 120 v.  Chances are good that Mark's receptacles actually measure closer to 220 than 240.

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You do all realize that was a table saw joke, right?  So we'll pause now for gales of uproarious laughter... ha....  OK, and with that we can return to our regularly scheduled serious conversation.

So no, the electrician didn't print the labels, that was my idea.   We'll have to wait for drzaius for conformation, but maybe this will help:).

20190604_104448.thumb.jpg.bc94906fcf77c30352550e8e89c765b8.jpg

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6 hours ago, wtnhighlander said:

@drzaius, why is it such a peeve? I work in an industrial facility, dealing with AC power distribution, at (rated) voltage levels of 161kv, 33 kv, 4160 v, 480 v, 240 v and 120 v. 

None of them ever MEASURE at the rated level.  Although the incoming line measures 167 kv (not 161), system impedance and load results in a wall socket voltage closer to 110 v (or less) than 120 v.  Chances are good that Mark's receptacles actually measure closer to 220 than 240.

Systems should be referred to by their nominal voltages, not by some number that was used around the time electricity was invented. Residential is usually 120/240V, or 120/208V if multi-family that uses a 3 phase main service. Commercial & light industrial  is 277/480V, 347/600V (Canada) & the high voltages that you mentioned. At least with the medium voltage systems, those are the target that you shoot for when designing & installing a system & they are the voltages that the utility delivers, +/- whatever tolerance they use.

I don't know of anywhere in Canada/US that uses 220V.

Not sure about the NEC, but CEC requires the voltage, under full load, at the point of use to be within 5% of the voltage at the service, so I'd be concerned if the voltage was closer to 220V than 240V. My experience is that the vast majority of cases, the utility actually delivers voltage that is a few volts above nominal.

All that being said, this is not going bring about the end of the world.

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I used to say "240", but so many others would call it "220" that I thought I had it wrong.  Now here I am vindicated!  

 

1 hour ago, Minnesota Steve said:

Well I'm glad it worked out!

I was curious to see how you eventually moved it.   I need/want to move my Sawstop PCS and Powermatic PM54a down into the basement, and am planning to do some disassembly to make it easier.

I have to say there is a lot to be said for hiring movers.  Pretty typically around here they have a three hour minimum so it can be expensive, but if you have more than one item it get's better.  The stair climber worked, but for the problem with the steepness of the stairs.  If you go the stair climber route consider leaving the cast iron top on the saw.  Our problem was that the center of gravity  was too low.  Although the unit would have been a hundred pounds heavier with the top on, the COG would have been higher. 

Then there's the door where Carol Marol is standing,  hire someone else to worry about it. 

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My understanding is that 110/220 was the standard "back in the day" but was at some point raised to 120/240 as standard. Also that if a modern item says it is rated for 110v or 115v, it means that it was tested to operate normally at the lower than standard voltage (potentially seen if using very long extension cords or very old wiring).

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59 minutes ago, Mark J said:

I used to say "240", but so many others would call it "220" that I thought I had it wrong.  Now here I am vindicated!

And there ain't no such thing as 110 either :)

I feel like we're making the world a better place here, 1 post at a time.

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32 minutes ago, JohnG said:

My understanding is that 110/220 was the standard "back in the day" but was at some point raised to 120/240 as standard. Also that if a modern item says it is rated for 110v or 115v, it means that it was tested to operate normally at the lower than standard voltage (potentially seen if using very long extension cords or very old wiring).

I think you're right, but that was so long ago that even the salty old journeymen that I apprenticed (40+ years ago) under didn't call it 110 or 220

Just to be clear, what I'm referring to here are system voltages. Lest things be too cut & dried, motor ratings can be all over the map. Most commonly they will have a 115V or 230V label rating, but a 230V motor is engineered to run on voltages from 208V to 240V. Although it is not uncommon for manufacturers of European motors to insist a boost transformer be installed when running one of their 230V motors on a 208V system

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Voltage was standardized nationwide in the 1930's. Before then, it varied depending on who was generating it, but Edison first chose 110v for his light bulb.  The oldest electrician I ever knew was a boy then, but he always called it 110/220.  I worked for him in Summers before I was old enough for a drivers license.  I never understood why it was always called 110/220, but everyone I knew growing up called it that.

Google found this excellent explanation-copied and pasted:

Steve Nations, Mechanical Engineer, Home Inspector
Updated May 25 2017 · Author has 222 answers and 295.5k answer views
 

In the U.S.: we use 120/240.

The first power systems were 110 volts. Edison chose that as a good compromise voltage to make his light bulb work well (this voltage was high enough that the bulb gave off a good amount of light, but this voltage was not so high that it caused the bulb to burn out quickly).

The 110 volts system meant that about 100 volts would actually be delivered to the point of use.

By the 1930’s the voltage had increased to 115 volts. (I don’t really understand why — I just know that it happened.) In 1968 the National Electrical Code (NEC) finally changed the values for motor ratings to reflect this voltage.

In the early 1970’s document C84.1 from the American National Standards Institute (ANSI) included a maximum deviation from standard voltage.

In 1984 the NEC was changed so that the standard voltage used for load calculations was changed to 120 volts. (Again I don’t really understand why the change happened, just that it did.)

Today utilities are required to supply you with voltage that doesn’t vary from 120 volts by more than 5% either way. So that would mean your voltage should be between 114 and 126 volts.

For some larger appliances you’ll use the two different legs of 120 volts to ground, so those appliances operate at 240 volts.

EDIT:

Since our electric system originally supplied 110 volts that value became embedded in people’s minds and a lot of people still refer to our system as 110/220. Since we used 115 volts for about 50 years a lot of people have that in their minds and still refer to our system as 115/230. But those days are long past. The U.S. is now 120/240 volts.

Most electric motors and many electrical appliances (especially those with motors) have a nameplate rating of 115 volts (meaning that they’re designed to run optimally at 115 volts). This is because they expect that if the utility supplies you with 120 volts at your main electrical panel there will be less than that by the time the current travels through your wires to the appliance. This is due to voltage drop.

EDIT #2:

Some homes in the United States don’t have 120/240, but instead they have 120/208. This isn’t common overall, but in some places most homes would have this.

Voltage of 120/240 comes from a standard single phase system, with two hot legs coming from the transformer, each being 120 volts to neutral, where the AC sine waves are 180 degrees out of phase.

But many industrial facilities use 3-phase power because it’s more efficient. A 3-phase Y system (there’s also a 3-phase Delta system) has 3 hot legs, each of which is 120 volts to neutral, and each of which is 208 volts to one of the other legs. Each leg’s AC sine wave is 120 degrees out of phase.

Because 3-phase power is more efficient, some utilities use it to supply residential properties too. So there will be a central transformer with a 3-phase Y system, and each home will have 2 of the 3 legs of that system, plus the neutral. To keep things balanced the missing leg will alternate among the properties served by that transformer.

There are some downsides to the homeowner with this type of system. An air conditioner is only going to see 208 volts instead of 240 volts, so it will have to work harder at the lower voltage. But pretty much all equipment is rated for either 240 or 208 volts, so it will be OK. Also, on a multiwire circuit the neutral wire will always see some current (you need to understand what a multiwire circuit is to make sense of this issue)

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3 hours ago, Tom King said:

But many industrial facilities use 3-phase power because it’s more efficient.

That's a good history lesson @Tom King. But I want to clarify the above statement. A 3 phase system is not more efficient from an energy loss standpoint. Single & 3 phase transmission and consumption efficiency are the same. Where 3 phase has a leg up (see what I did there?) is with regards to how much wire it takes to carry a given amount of energy, and how much simpler 3 phase motors are than single phase.

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