Motor Wiring

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mstrlucky74 said:
All it say here is #6. A few questions:

1. It was 2P so I need 2 phases.
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I suspect it single phase 240V, possibly off a 120-0-120V system without the zero being used.
You need to ask your supplier more questions.
 
infinity said:
Sounds like my Craftsman 6.5 HP compressor that has a motor nameplate amp rating of 15 amps which translates to about 1 HP at 120 volts. ...
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At the risk of getting up on my soapbox again, this is an example of yet another advantage of ditching the British system of weights & measures and using SI (metric) exclusively.

The SI system has only one unit of power, the watt. Were we using only one unit for each phenomenon, it would be more difficult for marketeers to pull crap like this. If a machine consumes only 1800 watts of electrical power, it's rather immediately obvious that there's no way it can convert that into 4850 watts of mechanical power.

(the same would be true if we used the British system exclusively and expressed both mechanical and electrical power in (the same) horsepower)
 
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drcampbell said:
At the risk of getting up on my soapbox again, this is an example of yet another advantage of ditching the British system of weights & measures and using SI (metric) exclusively.
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A number of times here I have suggested using SI. It didn't go down too well..........:blink:
At the risk of being a pedant, Système Internationale is not exactly metric. You can't express volts or ohms in metres

Apologies for the bold.
 
drcampbell said:
At the risk of getting up on my soapbox again, this is an example of yet another advantage of ditching the British system of weights & measures and using SI (metric) exclusively.

The SI system has only one unit of power, the watt. Were we using only one unit for each phenomenon, it would be more difficult for marketeers to pull crap like this. If a machine consumes only 1800 watts of electrical power, it's rather immediately obvious that there's no way it can convert that into 4850 watts of mechanical power.

(the same would be true if we used the British system exclusively and expressed both mechanical and electrical power in (the same) horsepower)
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Would that stop some tool manufacturers from giving the appearance of "more power" by stating a peak power output instead of a steady power output? I doubt it.

Simply stating output in watts can make it look "bigger" to some simply because the number printed on the label is a larger number than it would be if it were stating output in horsepower.

Then if one says 4000 watts but the next says 4kW, some may not realize that is the same either.
 
kwired said:
Then if one says 4000 watts but the next says 4kW, some may not realize that is the same either.
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If not, it's debatable whether they should be in the electrical business.
But the point is that we don't need different units for power. Power is power.
 
infinity said:
Sounds like my Craftsman 6.5 HP compressor that has a motor nameplate amp rating of 15 amps which translates to about 1 HP at 120 volts. :roll:

In the case of mrlucky's installation the HP rating of the unit is irrelevant, he has the engineered conductor size of #6 AWG and a 2 pole 45 amp OCPD so he can just follow that.
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I know dumb question...but it would be 2 hots and a ground?
 
Besoeker3 said:
If not, it's debatable whether they should be in the electrical business.
But the point is that we don't need different units for power. Power is power.
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I'm talking about markings on power tools and what it means to consumers of said products here.

You may not see much if any of what we see over here. There are tools with big print somewhere that say 3, 5, maybe even 6 HP, yet if they were able to deliver that kind of power for any considerable duration would not be able to operate on a 15/20 amp 120 volt supply circuit without overloading it. Those markings are peak power that can be output for short time, the actual continuous rating of the motor is probably at least half the peak value and many cases even less than that.

You do mark motors in watts AFAIK. When it comes to electrical professionals, yes it would be debatable if they can't figure that out, and because of common use of SI units where you are many probably do know what the difference between watts and kilowatts means. Here if you had two of the same item but marked one 2000 watts and the other one 2.0 kW, I can almost assure you there will be many average consumers that think the 2000 watt unit has "more power".

That seems to be the American way, bend the truth as far as you can to get your way, with about anything these days. Then there is too many "suckers" that won't educate themselves to figure things out for themselves. Sad part is some of those people also have at least some higher level education.
 
Besoeker3 said:
A number of times here I have suggested using SI. It didn't go down too well. ...
At the risk of being a pedant, Système Internationale is not exactly metric. You can't express volts or ohms in metres. ...
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No, but SI does define the volt and the ohm and make them consistent with the rest of the system.

The ampere is a base unit, defined by the magnetic force it creates in a pair of conductors.
The coulomb is one ampere·second
The volt is one joule per coulomb
and the ohm is one volt per ampere

https://physics.nist.gov/cuu/Units/units.html



retirede said:
I don’t know...a marketeer can lie in any language and in any unit of measure.
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True, but were we using one consistent system of weights & measures, their lying would be a lot more obvious.
 
drcampbell said:
No, but SI does define the volt and the ohm and make them consistent with the rest of the system.

The ampere is a base unit, defined by the magnetic force it creates in a pair of conductors.
The coulomb is one ampere·second
The volt is one joule per coulomb
and the ohm is one volt per ampere

https://physics.nist.gov/cuu/Units/units.html




True, but were we using one consistent system of weights & measures, their lying would be a lot more obvious.
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More obvious to those of us with at least some technical background.

To the average purchaser of a "6 HP" compressor, all they see is that a bigger number is better. They have little to no understanding of these units or the relationship between them.
 
retirede said:
More obvious to those of us with at least some technical background.

To the average purchaser of a "6 HP" compressor, all they see is that a bigger number is better. They have little to no understanding of these units or the relationship between them.
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Can be just as misleading to some extent to put same compressor on a larger tank.
 
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