First cut.

[Big Wave D]

My acetylene bottle is getting low, I figured a $7.00 tip was cheaper than having my bottle filled.

Now that, I understand. :thumbsup:

 

[Big Wave D]

To anyone with a plasma cutter, how much cutting does $7 worth of electricity get you? (Probably a rather tough thing to quantify. Guess-timates are fine. )

 

[dynasim]

The following is a quick(conservative) energy analysis for a plasma cutter cost. It does not include the cost of tip consumables. I think it is right, but others should check.

Amp Load 20A Compressor+Cutter
Voltage Supply 220 V
Elec. Rate 0.1 $/KVAHr(~KWhr)
Power Cost 0.44 $/hr Power Cost= V X A / 1000 X Price

Cut Speed 5 in/min
Cut Cost 0.00147 $/inch
Cut Cost 0.147 cents/inch

Chris

 

[deereman75]

The following is a quick(conservative) energy analysis for a plasma cutter cost. It does not include the cost of tip consumables. I think it is right, but others should check.

Amp Load 20A Compressor+Cutter
Voltage Supply 220 V
Elec. Rate 0.1 $/KVAHr(~KWhr)
Power Cost 0.44 $/hr Power Cost= V X A / 1000 X Price

Cut Speed 5 in/min
Cut Cost 0.00147 $/inch
Cut Cost 0.147 cents/inch

Chris

One issue I see is the amp draw. Just my 220v compressor alone draws 17 amps, the least I see for any plasma is 15 amp draw, so I would have calculated it for atleast 30 amps, if not 40.

 

[dynasim]

My compressor pulls about 8-10 amps at 120 V, and only runs about 30% of the time. I haven't run for really long periods, though.

Chris

 

[dynasim]

I haven't run my plasma cutter(for long periods of time), but the stated air consumption rate for my machine is 3.5 cfm.

The Everlast pp50 uses 31 amps at 220V at maximum power. I have only run mine at half power.

30-40 amps all in may be a better number. The 5 in/min was where I had put padding. I have cut a 6 foot square tube lengthwise(1/8" thick) in about 1-2 minutes per side(cleanly). That comes to 35-72 inches per minute. That is why I haven't run the plasma for long periods of time.

Chris

 

[yomax4]

If the 0.147 is correct, It's still worth it and probably similar to oxy fuel but you get to cut Cast, Stainless, Aluminum, Rust, Grease, Paint, Glass etc with Plasma. I find that you need a similar sized breaker for the output of the Plasma but they do build some of their own power. 80 amp Plasma likes an 80 amp breaker.

 

[deereman75]

My compressor pulls about 8-10 amps at 120 V, and only runs about 30% of the time. I haven't run for really long periods, though.

Chris

I guess I forgot how little air a plasma draws. I was just doing some sandblasting yesterday, so my mind was kind of on almost constant run. Gotta love a big air compressor.

 

[Big Wave D]

How does the price/inch of plasma compare to the use of O/A for cutting per inch?

 

[dynasim]

Here is Hypertherm's take on variable cost:

https://www.hypertherm.com/en/pdfs/PMX1650OperatingCost.pdf

Note that this is by a manufacturer of plasma cutters. Also note that the consumable(tip) cost is more than the electricity cost. The plasma that they are using for comparison must be significantly bigger than mine.

Chris

The root link:
https://www.hypertherm.com/en/Training_and_Education/Plasma_or_Oxyfuel/lower_cost_per_part.jsp