Page 1 of 2 12 LastLast
Results 1 to 15 of 20

Thread: How much does a DC cost to run?

  1. #1
    Join Date
    Jul 2016
    Location
    Lebanon, TN
    Posts
    1,719

    How much does a DC cost to run?

    For the electrical wise out there, is there a device that will measure the electrical current drawn, being used, by something like a DC?

    I currently run my DC as needed when I turn my saw of planer on. My DC is a 1.5HP 110v unit.

    I'm getting quotes for adding an extra bay to my current 30'x 30' garage, making it 44' x 30'. If this happens, I will most likely re-duct my entire shop and go with a much more powerful DC, 3HP or 5HP.

    I'm about to get a small hobbyist CNC which will require me to run the DC for several hours at a time.

    So I'm trying to figure out what is my best approach for chip/dust collection for the CNC. Is it a 220v 3 to 5HP DC, or my 1.5HP 110v DC, or maybe a stand alone shopvac.

    And back to my opening question, I'm trying to figure out what the cost of running the CNC is likely to be.

    Thanks

  2. #2
    Join Date
    Mar 2003
    Location
    San Francisco, CA
    Posts
    10,301
    The cost of electricity varies quite a bit around the US, so you need to look at your utility bill to see what you pay per kilowatt-hour.

    Unlike the other motors in your shop, a dust collector's motor runs at pretty near full power all the time it is on. One horsepower is 750 watts, so your 5 HP DC would be eating about 4 kilowatts when it is running. (I'm making approximations here, and ignoring some second-order effects, but for your purposes, this is close enough.)

  3. #3
    Join Date
    Mar 2003
    Location
    San Francisco, CA
    Posts
    10,301
    Lebanon TN Utilities web site says they charge ten cents per kilowatt-hour for residential use.

  4. #4
    Quote Originally Posted by ChrisA Edwards View Post
    For the electrical wise out there, is there a device that will measure the electrical current drawn, being used, by something like a DC?

    I currently run my DC as needed when I turn my saw of planer on. My DC is a 1.5HP 110v unit.

    I'm getting quotes for adding an extra bay to my current 30'x 30' garage, making it 44' x 30'. If this happens, I will most likely re-duct my entire shop and go with a much more powerful DC, 3HP or 5HP.

    I'm about to get a small hobbyist CNC which will require me to run the DC for several hours at a time.

    So I'm trying to figure out what is my best approach for chip/dust collection for the CNC. Is it a 220v 3 to 5HP DC, or my 1.5HP 110v DC, or maybe a stand alone shopvac.

    And back to my opening question, I'm trying to figure out what the cost of running the CNC is likely to be.

    Thanks
    The hard part about estimating operating cost accurately would be that its totally dependent on the number of gates open. If the DC is moving very little air (one gate) it will eat less power, all gates, wide open, it will pull the rated current. I honestly think it will be far less than you'd imagine especially compared to having a screamer shop-vac running all the time in an attempt to save power. Shop-vac's waste miles of electricity to heat.

    With regards to your CNC if you have ample dust pickup I will guarantee you the cleanliness of your shop will far outweigh whatever the DC costs you to run.

  5. #5
    Join Date
    May 2018
    Location
    Lancaster, Ohio
    Posts
    1,346
    Quote Originally Posted by Mark Bolton View Post
    The hard part about estimating operating cost accurately would be that its totally dependent on the number of gates open. If the DC is moving very little air (one gate) it will eat less power, all gates, wide open, it will pull the rated current. I honestly think it will be far less than you'd imagine especially compared to having a screamer shop-vac running all the time in an attempt to save power. Shop-vac's waste miles of electricity to heat.

    With regards to your CNC if you have ample dust pickup I will guarantee you the cleanliness of your shop will far outweigh whatever the DC costs you to run.

    Well said Mark
    Get at least a 5hp. A 7.5 or 10 won't be too much. The percent of the DC cost verus total cost of this project is small, so don't cheap out on the dust collector. Check and compare actual cfm at actual vacuum pressures of the different DC's then decide
    Ron

  6. #6
    Join Date
    Jul 2016
    Location
    Lebanon, TN
    Posts
    1,719
    Thank you for your replies. Curiosity got the better of me, so I ordered clamp meter.

    I will create a little pigtail box with two sockets, a NEMA-20 socket for 220v and a standard 110v socket.

    I will run two sets of wire, one for each socket and terminate them outside with the appropriate plug. On each set of wires, I will strip away some of the the outer insulation, so I have access to the two hots on the 220v wire and the single hot on the 110v so I can put a hot wire in the clamp meter. My thinking, I should be able to plug my tool into pigtail socket and then the pigtail plug into my wall outlet and measure the Amp draw.

  7. #7
    Join Date
    Mar 2003
    Location
    San Francisco, CA
    Posts
    10,301
    You might be able to measure the power drawn by a machine without buying a meter. There is a power meter on the electric feed into your house. It definitely will measure the power being drawn by your tool, whatever it is. The hang-up may be that your tool draws so little that you can't see its effect because of the other electric machines in your house.

  8. #8
    Join Date
    Jan 2010
    Location
    Tampa Bay, FL
    Posts
    3,885
    Quote Originally Posted by Jamie Buxton View Post
    Lebanon TN Utilities web site says they charge ten cents per kilowatt-hour for residential use.
    That's a pretty cheap electric rate. We pay $0.13/kWh.

    A quick check shows that rural Alaska charges $0.44/kWh, and Hawaii charges $0.33/kWh. Strangely, Douglas, Washington charges the least $0.03/kWh followed by Upstate NY (Niagara Falls??).

    A few years ago I bought a Digital ammeter for my drum sander. You could easily do the same for your dust collector.
    Last edited by Alan Lightstone; 09-28-2021 at 9:18 AM.
    - After I ask a stranger if I can pet their dog and they say yes, I like to respond, "I'll keep that in mind" and walk off
    - It's above my pay grade. Mongo only pawn in game of life.

  9. #9
    Join Date
    Mar 2013
    Location
    Taipei, Taiwan
    Posts
    537
    You will need to figure out how much electricity rate is in your area as it varies enormously. California for example has really high utility costs while other state may cost less.

    In Taiwan utility is government run, and residential rate is tiered based on total usage. It starts at around 6 cents per kwh, averaging around 10 cents, and with a maximum possible rate of 18 cents per kwh during the summer (summer rate is higher than winter rate due to AC usage).

    If you have peak demand vs off peak then it adds another complication to the price.

    But your best bet is measure its full running amp draw and multiply by its line voltage to get power draw.
    Typhoon Guitars

  10. #10
    Join Date
    Sep 2016
    Location
    Modesto, CA, USA
    Posts
    9,811
    One HP is 750 watts output but the the input is more like 1,000 watts.
    Bill D

  11. #11
    Join Date
    Feb 2013
    Location
    Tippecanoe County, IN
    Posts
    836
    Quote Originally Posted by ChrisA Edwards View Post
    Thank you for your replies. Curiosity got the better of me, so I ordered clamp meter.

    I will create a little pigtail box with two sockets, a NEMA-20 socket for 220v and a standard 110v socket.

    I will run two sets of wire, one for each socket and terminate them outside with the appropriate plug. On each set of wires, I will strip away some of the the outer insulation, so I have access to the two hots on the 220v wire and the single hot on the 110v so I can put a hot wire in the clamp meter. My thinking, I should be able to plug my tool into pigtail socket and then the pigtail plug into my wall outlet and measure the Amp draw.
    That will not be useful for determining power draw. You also need to know the power factor. Power = Volt x Amp x Power Factor. Power factor can be quite low for a motor operating at less than full power.

    Simple answer to the original question: Approximately $.10 per advertised horsepower per hour

    This assumes about $0.15/kwh electricity and the DC operating at 50 to 75% or so of maximum.
    Beranek's Law:

    It has been remarked that if one selects his own components, builds his own enclosure, and is convinced he has made a wise choice of design, then his own loudspeaker sounds better to him than does anyone else's loudspeaker. In this case, the frequency response of the loudspeaker seems to play only a minor part in forming a person's opinion.
    L.L. Beranek, Acoustics (McGraw-Hill, New York, 1954), p.208.

  12. #12
    Join Date
    May 2005
    Location
    Highland MI
    Posts
    4,508
    Blog Entries
    11
    Quote Originally Posted by Mark Bolton View Post
    The hard part about estimating operating cost accurately would be that its totally dependent on the number of gates open. If the DC is moving very little air (one gate) it will eat less power, all gates, wide open, it will pull the rated current.
    I have a 2 hp Oneida SDG running on 240 volts. All gates closed it draws 8.2 amps, two gates open (3" and 5") for my TS, it draws 10.2 amps. Not that much different. Installed a cheap direct-from-China ammeter.

    https://www.youtube.com/watch?v=XGIe...el=OleAnderson
    Last edited by Ole Anderson; 09-29-2021 at 9:09 AM.
    NOW you tell me...

  13. #13
    Join Date
    Jan 2017
    Location
    MT
    Posts
    698
    Quote Originally Posted by Alan Lightstone View Post
    That's a pretty cheap electric rate. We pay $0.13/kWh.

    A quick check shows that rural Alaska charges $0.44/kWh, and Hawaii charges $0.33/kWh. Strangely, Douglas, Washington charges the least $0.03/kWh followed by Upstate NY (Niagara Falls??).

    A few years ago I bought a Digital ammeter for my drum sander. You could easily do the same for your dust collector.
    Washington State has lots of hydro.

    We are fortunate in my part of Montana to have a local hydro dam. We pay less than $.07
    Regards,

    Kris

  14. #14
    Join Date
    Sep 2008
    Location
    N. Idaho
    Posts
    1,621
    Good thread. To the original question in a very back-of-the-envelope way: ~1000 W /horsepower * $0.10 / 1000W hr = ~$0.10 / hour for each HP. At 2 HP, ~$1.60 / eight hour day of operation. +/- 50%
    "You can observe a lot just by watching."
    --Yogi Berra

  15. #15
    Join Date
    Sep 2015
    Location
    San Diego, Ca
    Posts
    1,647
    I am primarily a hobbiest woodturner with a DC. So, when I read (above) that the cost might be $1.60 a (working day) I think that it really doesn't matter all than much. When I'm in the shop turning, I may only have the DC on for a couple of hours. If I'm turning green wood, I might not turn on the DC as very little dust is generate. When I'm sanding is when I turn on the DC.

    I also do aluminum metal casting with an electric kiln. It draws 1.5 KW. So in my over-priced area that equates to less than $ 0.50 an hour. I may run it for a couple of hours max while casting. So, I use $20 of aluminum and a buck of electricity.

    So, I really don't think that the cost of electricity is a major factor here. Maybe it is like calculating the cost of sand paper per project. Someone said that we should be using sandpaper like someone ELSE is paying for it.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •