115V vs. 230V

Patrice Lemée

Patrice Lemée

Joined
Aug 13, 2002
Messages
5,703
Yes, again.

Someone in another thread said that they did not see the big deal about motors above 1.5hp for a grinder, kmg in my case. So should I upgrade the shop to the higher voltage or not? Just a hobby maker I am. And finally, does the same apply to a flat disk grinder?

Thanks for your help.

Pad
 
230 volt uses less Kw hrs of electricity. Also it will lug down far less when performing operations such as grinding. If you can do the electrical upgrade yourself the investment will prove more than worth it. This will prove doubly true if you add other machines such as a vertical mill at a later date.
 
wildmike said:
230 volt uses less Kw hrs of electricity. Also it will lug down far less when performing operations such as grinding. If you can do the electrical upgrade yourself the investment will prove more than worth it. This will prove doubly true if you add other machines such as a vertical mill at a later date.
Click to expand...

Where do you get your info??

The same energy is used whether we use 110 or 220 V voltage. If it were
different, we could save energy by switching but we don't.
110 V, the motor would draw twice the current that it would from a 220 V
supply line. The product of V (voltage) x I (current) is P (power), which is
the energy an motor needs to run on per second, remains the same.
 
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220 will be nice to have for other tooling later on. If you were thinking or planning to put it in, then go ahead and do it.

220 does not use less power than 110, as already mentioned.
 
I put a 1.5 HP motor wired for 115V on my Kalamazoo grinder. I may switch it around to 230V if and when I have an outlet installed in the garage for my kiln. The current draw is something like 15-16 amps when in 115V configuration.
 
At a later date, you may decide you want to put in machinery that is 3 phase instead of single phase. If so, you'll need the 220 to run a converter.

Most of us start out as hobby makers and get more serious as our skills progress.
I am glad I have the 220 in my shop. I am using a 3 phase mill,
that I did not see coming when I started ten years ago.

Since I am set up with a single to three phase converter, I am looking for a surface grinder as well.

If you think there is a possibility that you might want to expand your shop, put the upgrade in. You will not regret it.:thumbup:

Best of luck to you, Fred
 
Fred.Rowe said:
At a later date, you may decide you want to put in machinery that is 3 phase instead of single phase. If so, you'll need the 220 to run a converter.

Most of us start out as hobby makers and get more serious as our skills progress.
I am glad I have the 220 in my shop. I am using a 3 phase mill,
that I did not see coming when I started ten years ago.

Since I am set up with a single to three phase converter, I am looking for a surface grinder as well.

If you think there is a possibility that you might want to expand your shop, put the upgrade in. You will not regret it.:thumbup:

Best of luck to you, Fred
Click to expand...


Fred, you can run 3 phase off of a 120 line, simply run the wires to a 120V single phase motor equal or greater than the HP rating of the 3 phase motor you wish to run, then continue the wiring from the same terminals on the 120V motor through a toggle switch and capacitor (like that on a fluorescent light bulb) to the 3 phase motor and viola, cheap easy rotary phase converter.
 
I am installing 220v as we speak, I have the breaker and wire installed just need to wire into shop outlets.

The reason I am doing this is to split the load to two breakers (220v) because if I have my dust collector, spot lights and then switch on the grinder, its gets really dim... and sometimes I am outside resetting the breaker. This will split the load between two 20 amp breakers rather than one.

My 115 volt kiln takes a while to heat up, I will be installing 220v so I will have twice the power available.
 
Lets not forget welders and air compressors to the list of things you kinda need 220 for. On top of the list of; most kilns, lathes, mills, surface grinders, Etc.... Its not that you will ever need 220 but most of this stuff when you can find it in 115 is going to be to small, that is if you can find it in 115.
 
As a few people have previously mentioned, 240 volt does not use less kWhr than 120 volts. Power is power. Wiring for 240 volt does have it's advantages however. A 1.5hp motor wired at 120 volts will draw more current than the same 1.5hp motor wired at 240 volts. One byproduct of current through a wire is heat. Heat in a wire reduces the conductivity of the wire (adds resistance). This really becomes an issue when you put a significant amount of physical resistance on the motor (when you are really HOGGING material on your grinder for example). This load on the motor can cause the coils to heat up, which in turn increases the resistance of the coil and can cause the motor to bog down. This is more of an issue when motors are wired at 120-volts than in those wired at 240-volts because they are drawing twice the current to start with.

I have a Grizzly cabinet table saw that came to me wired for 120v. After owning for a couple months I rewired to 240v. It is quite noticable how much more the saw can take before it bogs down. Go for 240v... you won't be sorry.:)

Erin

wildmike said:
230 volt uses less Kw hrs of electricity. Also it will lug down far less when performing operations such as grinding. If you can do the electrical upgrade yourself the investment will prove more than worth it. This will prove doubly true if you add other machines such as a vertical mill at a later date.
Click to expand...
 
Sam Salvati said:
Fred, you can run 3 phase off of a 120 line, simply run the wires to a 120V single phase motor equal or greater than the HP rating of the 3 phase motor you wish to run, then continue the wiring from the same terminals on the 120V motor through a toggle switch and capacitor (like that on a fluorescent light bulb) to the 3 phase motor and viola, cheap easy rotary phase converter.
Click to expand...
Sam,

Does that set up give you full voltage?



Fred
 
Single phase may be a bit of a misnomer. You need two slots in your breaker box for 220, so arguably any 220 line run though a standard household breaker panel is arguably "2 phase" For 3 phase, you just ad another leg. At least that is what my electrician told me. Fi you are short on space in your breaker panel like I was at my shop (shared main panel)you can drop in a double switch breaker inot one or more of your 110 slots and run two circuits through a single slot space. Remeber that you do have to pull new wire for any 220 circuit. I have two 220/20 circuits in my shop for my Paragon and my press. If I ever manage to get the 25 lbs little giant that I bought 8 months ago shipped, I will run it off 220/30 too.
 
I think it's more complex than just a third leg, if you simply ran another 110V leg you'd have 330 volts. My understanding of three phase power is that each phase is timed differently and true three phase power comes from three phase service using different transformers.
 
Actually, the same motor when wired for 230 VAC will use slightly less power because it will run more efficiently. It will run at less amps and amps * resistance == heat generated and every bit of heat generated is lost efficiency...not to mention shorter life of the motor.

We won't get into phase shifts and their effect on efficiency, though the EE in me wants to throw that out too. Ugh, reactance calculations...:barf:

Anyway, single phase 120 VAC pretty much tops out at 1 Hp for most continuous duty motors. You can get bigger motors, but you go over the 15 amp level so they are not nearly as common.

As a general rule, high voltage is more energy efficient than high amperage...sometimes a lot. That's why transmission lines run at such high voltage.
 
AcridSaint said:
I think it's more complex than just a third leg, if you simply ran another 110V leg you'd have 330 volts. My understanding of three phase power is that each phase is timed differently and true three phase power comes from three phase service using different transformers.
Click to expand...

To put it simply, think of the AC power as a sine wave. There are 360 degrees in a full cycle. US style 230 is a 'split phase' where the 2 phases are 180 degrees opposed to one another. 3 phase circuits are 120 degrees apart in the cycles and are generated and transformed through a transformer with 3 separate coils. A single coil with a center neutral tap is used to generate the 230 VAC split phase...so it is technically considered single phase.

On 3 phase systems the voltage is measures line to line, but (assuming a WYE grounded transformer) the voltage to ground should actually be the V(L-L) / squareroot(3) or in the case of 480 nominal VAC 3 phase, V-ground is 277 VAC nominal...hecce the (seemingly odd) 277VAC lighting you see all over large commercial and industrial facilities.

More than you wanted to know, I'm sure, but this is my career...:D
 
lets see a 1.5hp motor on 110 will pull some where in the range of 1 1/2 14-20 amps and for a 220 motor it will pull around 7- 9 amps. and since the electric company charges you for the largest load on the highest leg. it would be wise to go with 220. and while E*I=W Or Power

so 20ax110v=2200w
and 9ax220v=1980w realy close to the same amount of power
but the electric company is going to charge you for the higher amperage on the higher leg of peak power as in the 110, if you pull 20a on one side and 3a on the other you get charged for 20a on the highest leg of amp draw..
and if you use 220 you split the load causing the amp draw to be less on both sides, so the same motor is pulling 9a and you get charged for 9a on the highest leg of amp draw.

if the load is ballanced then you get charged for a blanced load or about half of what the 110 is. this is why when you wire a house you never put 110apliances on the same leg, ie: washer and refrigerator on seperate legs to balance load.
 
Hi Rusty, I think I may be missing something in your post above. I see what you're saying that the motor may draw more amps in 110V configuration, but are you saying that you'll get charged for a 20A draw on both legs of the 110V and only 9A for each leg of the 220?
 
Yep that's how it works, you get charged for the highest draw of either of the two legs.
 
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Rusty McDonald said:
Yep that's how it works
Click to expand...

Gotta disagree with you partly here Rusty... I am an electrical engineer for a power company. This info may vary from power company to power company, but here's what we do:

Most power is billed primarily on a KWH basis. This is power consumed for a length of time.

Residential and small customers are billed ONLY on a KWH basis. They are not billed on amps of demand (or max amps on the high leg like you are talking about). In fact most residential meters do not even have the capability to record max amp demand.

Commercial and Industrial customers (those of sufficient size) are metered and billed differently. They are billed on KWH of power used, but we also charge them a "demand" charge. This type of customer will often have LARGE motor loads. While these loads may only be on-line intermittently, we, as a power company, need to provide them with enough capacity for the full load. They may only operate at a high demand for a small fraction of the day, but we charge them the extra "demand fee" for the capacity. Meters on this type of installation will be have the ability to record KWH consumed, peak demand, and oftentimes other data like KVARs, power factor, etc. In general, the customers will be billed for KWH consumed and demand charge... though LARGE customers can also be charged for combinations of KWH, Demand, KVars, power factor , etc.

So it all depend on what type of customer you are. In general, if your are residential with a small shop... KWH use only. If you are commercial/industrial then demand becomes an issue.

Erin
 
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