3 phase possibly?

[discotroll]

Morning all -

Bit of a newbie/possibly dumb question here but I'm sure you'll point me in the right direction...

I'm soon to be cutting a lot of steel plate - from 10mm to 20mm thick and am now turning my attention to the plasma cutter best suited to the task. I've only got single phase (32a) 240v power but was wondering if a 3 phase converter would be able to provide the power to run a larger machine making the cutting a lot simpler.

All thoughts welcome!

 

[MetalMonkey]

A three phase converter, either VFD or rotary, will generate three phase or an approximation of three phase, but obviously it can't produce any more power than you already have available to feed into it.
Actually, by the time you are done converting you will have lost quite a lot of power in the conversion. You may also find that the machine won't be happy running from VFD or RPC.

 

[Erie Fred]

Hypertherm 85 is the largest that can run on single phase, consult the charts for cutting 20mm IIRC it might be o.k.

 

[discotroll]

Hypertherm 85 is the largest that can run on single phase, consult the charts for cutting 20mm IIRC it might be o.k.

Yes - I've been eyeing up the Hypertherm unit as a possible single phase unit...

 

[MetalMonkey]

Hypertherm 85 is the largest that can run on single phase, consult the charts for cutting 20mm IIRC it might be o.k.

They only seem to list those for 415V, but if he could get a single phase unit, then he could potentially put in a larger supply from the consumer unit.

 

[Erie Fred]

Powermax85 SYNC plasma cutter and consumables | Hypertherm

Where to buy, cartridge consumables, cut charts, specs, and manuals for the Hypertherm Powermax85 SYNC® plasma cutter.

www.hypertherm.com

CSA 200–480 V, 1-PH, 50/60 Hz 200–600 V, 3-PH, 50/60 Hz CE 380/400 V, 3-PH, 50/60 Hz

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Input voltages​

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[Munkul]

you're going to need more than 32 amps of 240v. You'll need a 63 amp circuit for an 80 amp plasma in 240v 1ph.

 

[discotroll]

So I think that answers the 3-phase question for me (as in a big fat "NO"!) .
So.... is there any argument for switching to oxy acetylene??

 

[Munkul]

Are you just cutting straight lines? Oxy will probably be best in that case. It makes a neater job than plasma freehand anyway.
You could always get a track cutter also, they work great for neatness and repeatability.

 

[Erie Fred]

So I think that answers the 3-phase question for me (as in a big fat "NO"!) .
So.... is there any argument for switching to oxy acetylene??

Sure, I use it when over 5/8" , I did some 1" thick and used the Oxy torch on the table.

Just remember, unlike Plasma you cannot simply set your parameters, push GO, and walk away.

Also, Oxy can only cut steel, no aluminum nor stainless.

Check out SnowBall Engineering on YT, he does both on his table too.

 

[knighty]

how clean do you need the cut?

my cheap Chinese plasma cutter running from a 13amp plug cuts 10mm no problem

can't imagine you need a massive machine to cut 20mm (smaller machine might just need a rest now and again if you're using it a lot)

(unless there's some weird rule where the power needed is a multiple of the thickness etc.)

 

[Erie Fred]

how clean do you need the cut?

my cheap Chinese plasma cutter running from a 13amp plug cuts 10mm no problem

can't imagine you need a massive machine to cut 20mm (smaller machine might just need a rest now and again if you're using it a lot)

(unless there's some weird rule where the power needed is a multiple of the thickness etc.)

Please consult some cutting charts.

 

[knighty]

Please consult some cutting charts.

I just did.... 55amps for 10mm 60amps for 20mm

which doesn’t need a massive machine unless you want 100% duty cycle


personally, I have no idea what the duty cycle of my machine is, because I've always run out of cutting before it trips off for thermal overload (and/or I'm cutting on/off not constantly)

 

[Erie Fred]

I just did.... 55amps for 10mm 60amps for 20mm

which doesn’t need a massive machine unless you want 100% duty cycle


personally, I have no idea what the duty cycle of my machine is, because I've always run out of cutting before it trips off for thermal overload (and/or I'm cutting on/off not constantly)

What machine ?

 

[discotroll]

My cuts don't need to be super clean and they're all just straight lines. I think the thing I want to avoid is getting something that struggles with the occasional thicker material and becomes painful to use if I'm left gauging my way through these pieces...

 

[knighty]

What machine ?

cheap Chinese clone, looks a bit like a cut40 ones did when they came out

it's advertised as 40 amps

I've had it for years, bought it when plasma cutters became more popular and prices started to drop, figured I'd buy a cheap one first to test with and upgrade if it was any good.... it's always done everything I've needed so I stuck with it


either way, if he only needs 60 amps to cut 20mm, a single phase machine should be more than happy doing that? - not even massive amps 240v supply into it either?

 

[Erie Fred]

cheap Chinese clone, looks a bit like a cut40 ones did when they came out

it's advertised as 40 amps

I've had it for years, bought it when plasma cutters became more popular and prices started to drop, figured I'd buy a cheap one first to test with and upgrade if it was any good.... it's always done everything I've needed so I stuck with it


either way, if he only needs 60 amps to cut 20mm, a single phase machine should be more than happy doing that? - not even massive amps 240v supply into it either?

I would say that cut chart is optimistic....very.

Powermax45 SYNC plasma cutter

Part of the Powermax family, the Powermax45 SYNC® features built-in intelligence and patented single-piece cartridges for hand cutting, gouging, or mechanized cutting.

www.hypertherm.com

Even the Hypertherm 45 amp machine is listing max cutting at 5/8".
CNC or machine cutting will be less, consult the proper charts for real information.

 

[steve t]

I would go with gas. Always handy to have anyway

 

[Kj1123]

I would say that cut chart is optimistic....very.

Powermax45 SYNC plasma cutter

Part of the Powermax family, the Powermax45 SYNC® features built-in intelligence and patented single-piece cartridges for hand cutting, gouging, or mechanized cutting.

www.hypertherm.com

Even the Hypertherm 45 amp machine is listing max cutting at 5/8".
CNC or machine cutting will be less, consult the proper charts for real information.

I have a hypertherm power max 45 xp single phase it will cut 20mm plate but pretty slow cut quality isn't optimal obviously as its outside its range. It cuts 12mm lovely and 15mm decent enough. If it an occasional bit of 20mm it would be fine however if cuts are long runs it's just too slow to be practical. Also consider your air requirements I have a fairly big 250l compressor and to be honest it's not big enough or maybe doesnt have enough cfm. I am looking to upgrade both compressor and plasma cutter in the future as I now have 3 phase power via generator.

 

[Munkul]

cheap Chinese clone, looks a bit like a cut40 ones did when they came out

it's advertised as 40 amps

I've had it for years, bought it when plasma cutters became more popular and prices started to drop, figured I'd buy a cheap one first to test with and upgrade if it was any good.... it's always done everything I've needed so I stuck with it


either way, if he only needs 60 amps to cut 20mm, a single phase machine should be more than happy doing that? - not even massive amps 240v supply into it either?

You're right, a 60 amp machine will cut 20mm...but it won't be happy doing it. Cuts will be rough and tapered. Even most 80 amp machines are only "just" good enough to rate for 20mm. My thermal dynamics 80 amp is awesome on 10mm... Good on 15mm... Just acceptable on 20mm.