2.2HP or 4HP Spindle?

[SomeSailor]

I'm getting close (probably Monday) on ordering a 48x96 PRSAlpha, and still have one nagging question:

I don't think I have enough power at the panel to support the 4HP spindle (90A) but do have enough for the 2.2HP spindle(60A). Would there be any significant reason that a 2.2HP wouldn't work for most applications?

I was actually a bit surprised at the higher 220V amperage required on these. Anyone running a 4HP spindle (1Ɵ) on something less than the 90A breaker as outlined?

I have a 185 TIG welder that gets by just fine on a 50A 220V breaker. Thanks in advance for any input.

[jerry_stanek]

I run my 2.2 on a 30 amp breaker and have no problems cutting anything.

[SomeSailor]

That's sort of what I'm thinking about the 4HP. I have a 60A breaker I can use (assuming the wife doesn't want the furnace at the same time) :)

I was wondering how often someone would load down a 4HP to the point it would kick breakers on a 50A or 60A circuit?

I do plan on cutting some aluminum, but we're only talking .125" thin plate.

[donclifton]

It rated at 9 amps, that would be a 20amp breaker and it doesn't come close to 9amp at full load due to the inverter.
Don Clifton

[Gary Campbell]

Mike...
Same here. 4hp HSD on a 30a single phase breaker. I pushed it hard and often. Never tripped the breaker

[frank134]

I run my 4hp spindle off of a 30 amp breaker. I checked the amp draw and it holds at around 9.2. that is the most it drawn so far. that was with a 1/2 bit cutting big dovetail in hard 2-1/2" maple for my new work bench

[SomeSailor]

That's probably what's confusing me then. The electrical requirements show a branch circuit protection of 90 amps (Electrical Requirements) (http://www.shopbottools.com/files/docs/SBG00350090707PRSalphaPowerReq.pdf).

But it has an input load of 30A on page 5. I'm assuming that is a fully bogged down spindle at it's maximum amperage. What's the 90 amps about?

Any thoughts are really appreciated and I'm really happy to be getting answers like this on my first post!

I'm pulling the trigger Monday, and don't wan't to second guess myself later if I buy the smaller and it won't run on the circuit I have. :(

[beacon14]

To answer your original question I've been able to cut everything including 1/4" aluminum with the 2.2hp spindle. But if you can swing the larger one then by all means...

[bcondon]

Mike

I use the 2.2 spindle and never had an issues with power...

You will need 1- 15 amp -120 v (single breaker) for your computer
1 - 30 Amp - 220V (double breaker) for the Spindle
and 1- 30 Amp - 120V (single poles breaker) for the controls


Bob Condon

[SomeSailor]

Thanks Bob / everyone;

I'll have to ask them about that then. That's really the only question I've got before pulling the trigger. I've got the funds all lined up finally and am anxious to add this to my little shop.

If you're able to cut .25" aluminum with the 2.2HP spindle it sounds like I'll probably go that route. I build custom marine dash panels and I'll never be any thicker than .125 anyhow.

Would the 4HP just be able cut faster than the 2.2HP I'm assuming?

[SomeSailor]

David; I saw in your signature that you have an alpha as well? Is it a 4HP on a standard 30A breaker? (I was just reading your blog about upgrading to the 4HP) :)

[chiloquinruss]

"I'll never be any thicker than .125 anyhow" Now see that's how we all started out! :) "All I'm going to use it for is . . . . !" :) It is so much easier to order it up front than it is to upgrade it later. Anyhow, you are going to have a ball learning how to use your new tool. The projects and prducts you now produce are just the begginning! Have fun. Russ

[SomeSailor]

No kidding Russ;

I'm just worried I'll start popping breakers with the 4HP. The electrical requirements say 90 amps, and I know I don't have that off my panel.

I have a plasma torch, 185A MIG welder and a large 220V heater, but can't figure why they would want 90 amps for this. :)

What are your thoughts?

[loriny]

4+ hp = 3000 watt = 13.6 amps @ 220V single phase? or not.
I currnetly run my whole shop on 50 amps single phase. Often running 3hp dust collector, 2 15A single phase vacs, 3000watt spindle, 5 HP woodmaster and if help is available a 3HP table saw and the lights. That said I never start 2 at the same time or even if another is under load.
The 4 HP should be no problem
Lorin

[donclifton]

What is being missed hear is the inverter (VFD) by changing the Hz to 300 instead of 60 Hz you amps at the panel is much less. This is why you can now run a mig welder off 120 volt. These are inverter welder instead of the old transformer type. I was a facilities engineer for 20 years we saved millions of dollars in energy by running our air handlers, pumps and a/c units on VFD. VFD have soft starts which eliminate the high starting amp that most motors have.
Don Clifton

[SomeSailor]

Thanks Donald;

So in your opinion then they're calculating the panel requirements wrong then? I do run some pretty high amperage loads here just fine (plasma torch comes to mind) but nothing ever comes close to needing 90 amps.

I've run my TIG on 30A power with no problem for many hours. Often pouring in very high current to weld aluminum. I was just hoping I was not missing something.

It's good to hear that others are running of smaller legs (30A and 40A) and having success (and letting out none of the magic smoke) :)

[beacon14]

To answer your other question I don't think you will cut faster in aluminum or most other materials with the larger spindle, you will have to optimize your feed speed based on the material, depth of cut, type and size of bit being used, etc. I suppose the larger unit will have more "oomph" for difficult cuts but as I say there is nothing I have not been able to cut with the 2.2 hp. I think one of the advantages of the larger unit is that it should last longer when used in production.

Someone correct me if I am wrong..

[donclifton]

I second that, Its always better not to run a machine on its limits. It looks like the 4hp is only $600 more and if you were to have to upgrade it would cost you a whole lot more.
Don Clifton

[mitch_prest]

Mike

you would be better off to get the 2.2 hp and spend the difference in money on bits... if you have not cut aluminum before.. you will certainly need a few extra when you get started... and you really are going to be limited by the material.. I cut 1/4" aluminum in a couple passes with the 2.2 on a prs alpha. I tried a single pass but the finish is just not there and it heats up far too quick.. the other thing you will need to spend money on is an air system to cool as you cut..

mitch