operating cost ; 1.5hp vs. 3hp vs. 5hp

Hopefully this has not been discussed to death. Just curious I tried searching but did not find much with "operating cost".

So there was posted here today a probably mistaken pricing on a 5HP 20amp PM2000. And I'm thinking wow maybe I could/should. But proably will be coulda/shoulda :(

But it got me wondering has there been much discussion on how much operating cost go up when you start using tools with more HP and Amps?

Would operating a 5hp saw cost all that much more than a 3hp? Or a 1.5hp vs. 3hp or 5hp.

Is not amp rating based on max amps at startup. What amps might a 5hp saw, like the PM2000 deal that was posted today, average after startup? Or do you determine cost using Watts when thinking about cost?

Power consumption in my home shop is going up for sure because I'm trying to get more serious with dust collection which opperates in conjunction with each tool either my Delta 1.5hp DC and/or my 6gal wet/dry vac, sometimes at the same time. And I'm planning on also adding an air fliltration system too eventually. And I'm wanting a more powerful table saw.

Grant.

Power use will go up with each increase in horsepower. The amount would be very small to a home/shop/owner. The saw would have to run fully loaded to see a significant increase.
5HP is overkill for a homeshop, unless you are planning to do some serious side work. 1 1/2HP will eventually leave you wanting to upgrade. 3HP is a nice size saw for a homeshop. Plenty of power.

Don't forget that increased HP means increased amp usage, which means a bigger breaker, bigger wire and possibly upgrading your service panel. My 3 HP Unisaw doesn't breath hard under much of any load except ripping thick stock.

Here is a little math that might answer your question.

Power rates are about $0.08 per KW-hour average in the US.

That saw will consume maybe 25A @ 240V under load which is 6 KW.

Each hour you run the saw will use 6 X $0.08 = $0.48 of electricity.

You can do a lot of sawing in an hour of continuous running in a hobby
shop. I doubt if most saws see an hour of continuous running in a
month. Commercial shops are a different story.

My opinion is that the energy cost difference between 3 HP and 5 HP
saws is so small as to not be worth considering.

Edit:I just noticed you live in CA. Double the previous estimates.

It's hard to quantify because I need to factor the weather but I can see a $30-$50 difference between the months I am spending a lot of time in the shop (>10 hours a week) and the months I am not.
I am running a 3HP cyclone, 5 HP TS and air filtration.

Quote:

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Originally Posted by Emmanuel Weber

It's hard to quantify because I need to factor the weather but I can see a $30-$50 difference between the months I am spending a lot of time in the shop (>10 hours a week) and the months I am not.
I am running a 3HP cyclone, 5 HP TS and air filtration.

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Seems about right to me.

My base operating bill is about $60 per month. Some months higher, some lower.

I'll bet that the cost of operating a saw don't change much with the change of motor horsepower. Basically, an electric motor like the one in your saw draws only as much power from the wall as it needs to do the job. If it running, but not cutting anything, it doesn't draw much power. If it is ripping thick oak very fast, it draws a lot more power. That is, your operating cost is governed more by the work you're doing than by the maximum-horsepower rating of the motor.

(The one machine in the shop which doesn't have this characteristic is the chip collector. In a chip collector, the motor is running at close to its rated horsepower all the time. So a 3 hp collector costs about three times as much to operate as a 1 hp collector.)

Ignoring the effect/efficiencies of the motors(should be negligible) the two saws would use the same amount of energy to do the same work. Either saw would have to be cutting wood to draw a lot of current. The 5 HP would have to be cutting more wood or cutting faster to draw more power than a 3HP saw.
Keep in mind that the dust collection is different. It draws the same power once it starts since it's moving air, therefore a larger dust collector would cost more to operate.

still, I agree that operating costs are very small and not really a factor. If anything the investment and wiring are the issues.

Quote:

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Originally Posted by Emmanuel Weber

It's hard to quantify because I need to factor the weather but I can see a $30-$50 difference between the months I am spending a lot of time in the shop (>10 hours a week) and the months I am not.
I am running a 3HP cyclone, 5 HP TS and air filtration.

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There are some other factors that should figure into that as well. If your in the shop, your at home with your a/c lower, heat higher (blower motor, etc), and using more lighting (safety, so you can see what your doing). So it's not just the equipment.


Not picking on you, just trying to show there are other factors for those figuring.:)

You won't notice any major difference when you get the bill unless you are working commercial and run that your saw 8 hours a day. Wiring should be more of a concern as I had to add a second 220 V when I added a PS cyclone.

Sarge..

All my shop has a dedicated sub panel that feed everything including lighting, dehumidifier and AC. If you guys buy me a nice digital panel meter I promess I will provide a monthly accurate reporting :)

One more factor for your decision making equation. The bigger the Hp, the stronger the kick back can be. If the blade pinches on a 1-1/2 Hp saw you probably can stall the motor by holding the board back. You may not be able to hold back a 5 Hp kick back.

Unless you're planning on running a powerfeeder or using dull blades to rip thick stock you won't see any improvement with a 5HP vs a 3HP saw. The operating costs of a tablesaw are insignificant relative to the cost of the wood you are cutting whether you have a commercial or hobby shop.

Greg