Powering an Electric Sawmill

Hello electricians and electrical engineering enthusiasts, I'm thinking about powering an electric sawmill with a Coleman Powermate generator.  All the details are in the pictures below, and summarized here...can you help me with this system design?

Background:
I would like to use an electric bandsaw sawmill (as opposed to gasoline powered one) to:
1) Keep the fumes out of my face
2) Allow for various power possibilities: off grid generator, or future grid-tied, or normal grid
3) Allow for potential indoor operations in the future

Equipment:
The AC motor on the HFE-21 electric sawmill from Hud-Son has the following specs:

Single phase / 5hp / 3.7kw / 230V / 20.3A

NEMA L6-30 plug

Presumed performance curves provided in chart below (found online from motor model number)

The generator I have at my disposal is a Coleman Powermate 5000 (specs provided in picture below):

5000w continuous, 6250w surge

NEMA L14-20R receptacle

240V, 20A max (according to manual)

240V, 20.8A (according to the nameplate)

Proposed configuration:

Coleman 5000 Powermate Genrator

Adapter to convert the outlet/plug types, such as a Fullsky FC-L42L631 Male 4-Prong 20Amp 125/250Volt NEMA L14-20P Locking Plug to L6-30R 30Amp 250Volt Locking Female Connector

Extension cord (TBD), either up or downstream the adapter, either an L14-20 or an L6-30

5hp electric sawmill

Design questions:
Q1: Will the 5000w generator suffice, especially given the 20A restriction listed in the manual, and the power requirements of the mill?
Q2: Will this proposed plug/receptacle adapter work, given its 20A rating?  
Q3: If so, what extension cord configuration seems best? NEMA L14-20 (20amp) okay?  Is an L6-30 (30amp) necessary, or is it overkill?
Q4: Any other concerns or tips to prevent an electrical catastrophe? Any electrical engineering tidbits to learn?
Q5 *BONUS*  Can an L6-30 extension cord be beneficial later on to charge an EV?

My main concern is that the generator's outlet receptacle (and proposed male-to-female adapter) are rated for 20A, but the current draw of the motor says 20.3A.  My hunch is that as long as I am not operating the machine above its 100% rating, then the current drawn won't be hot enough to release the magic smoke that makes it run.  I appreciate your tips and know-how!

Hi George,

This sounds like a neat project! As I am not an expert in electrical, take everything I say with a grain of salt and do wait on someone more knowledgeable to chime in before making any decisions.

From my understanding, the max output of the sawmill will be at motor start-up. If this is the case, then the 20.3 amps will only be pulled for at most a few seconds. It takes a lot of energy to get things from a standstill to the rated RPM.  You could potentially run into issues with your breaker tripping upon motor start up, but you also might not have any issues at all.

The rated current of 19.1 amps is below the limit of your generator receptacle and should cause no issues.

As for the other questions, I don't know! But I'll be following this thread with interest.

I know little about generators. I did run a company that did have a notcher, planner, saws, etc. that produced products for the mining industry.  Your arrangement strikes me as being on the light side. But do wait for input from others.

See right under your highlighting where it says “locked rotor current 124 A”?  

Some means is needed to reduce inrush current, such as a “Reduced voltage starter” of the type: Resistor, part winding, wye/delta or soft-start.

I guess a “Magnetic Electric Motor Starter” might work. This one says 22 Amps. I’m assuming the generator can surge 26 Amps (6250W/240V).  
https://www.amazon.com/Magnetic-Electric-Starter-Control-Single/dp/B00ATCCYXK/
Need to double check this.  

So I heard back from the sawmill manufacturer, and their recommendations jive with this forum and the math I found online -- so thanks, all, especially for that Locked Rotor Amperage (LRA) tip!  I'll share the math and what I learned...

Learning more about LRA lead me to this website, which was especially helpful:

   https://generators.smps.us/start.html
   https://generators.smps.us/surge-current-calculator.html

From there I learned:

The NEMA Code on that nameplate picture is listed as "G".  And this Code corresponds to a table used by the "National Electrical Code" which yields the LRA based off the nameplate horsepower rating (5hp).  In this case, Code "G" is expected to have "inrush" surge in KiloVoltAmps (kVA) to be 5.6–6.29 times the motor's HP.  That would expect surge power to be:

28kVA -- 31.45kVA

Divide that by 230V used by the motor, and that *would* yield a starting current (LRA) of about:

122A -- 137A

These values are accurate for mains power.  But does that mean I would need a 28kw genset? The answer is "no" because of "voltage sag".  The generator, unlike mains power, will result in the voltage "sagging" by the appliance (sawmill).  According to that website:

"Most residential appliances can start with up to 30% voltage sag, that is at 30% lower currents."

We know that:  
Power = Volts * Amps  
and also V = I*R

A 30% sag in voltage and 30% resulting lower current would mean the surge wattage to run this mill on a generator could be somewhere around:

230V*(70%)*122A*(70%) = 13750w [low estimate with sag]
230V*(70%)*137A*(70%) = 15440w [conservative estimate with sag]

The company recommended a 15kw generator, and if that didn't work, trying a 20kw - 24kw generator.  

They also recommended wires:
   10awg up to 50 ft.
   8awg up to 80ft
   6awg up to 125 ft.

It's hard to come to mental grips with, as the gas motor of this sawmill model uses a 6.5hp Vanguard engine, and the Coleman generator is using a 9hp Vanguard..but the generator is presumably insufficient!  That's trons for ya'.  Thanks all 👍.

P.s. I've decided against exploring a soft starter or hard start capacitor, as I wouldn't want to void a warranty!  Additionally, a key factor of electric for me is not regularly dealing with the nuisance of fuming gasoline engines.  So mains power it is!

George, how far away from your existing 230V supply do you need to situate the sawmill? It might be possible to get a pair of transformers to step up the voltage and use thinner cable for the distance, then step back down to motor requirements...if you can find them used. New 240/480V transformers in that range look pretty spendy.

Phil wrote:George, how far away from your existing...

Off-grid right now.  There's a broken telephone pole a long way away but that's it.  My original plan was to stay off-grid for a few years, using the sawmill to build all the initial Zone 2&3 farm structures (office, barn, fencing, trellises, animal pens, raised bed timbers etc) and then when business takes off, go on grid and eventually build the Zone 0 "forever home", and move the mill there.

Since my tiny generator isn't sufficient, nor can I borrow one big enough, I'll guess I'll have to go on grid sooner!  Probably going to work with a Distribution Designer next month to discuss the farm's electrical layout.  Fortunately, it's a very portable sawmill, so I think I'll put it very close (<50 feet) to a not-yet-installed meter base and/or sub-panel.  

Guess I should start searching around the forums to see other folk's experiences with going on-grid.  Kinda exciting to make progress toward long term goals!

The “Magnetic Electric Motor Starter” seems to work by temporarily putting an inductance in series with the (stopped) rotor, so that the load seen by the generator is closer to 11 ohms instead of 2 ohms. Thus the inrush current would be 22A instead of 124A.

Locked rotor impedance = 240v/124A = 1.93 ohm.

“Magnetic (Inductive) Electric Motor Starter” current 22A.
Impedance = 240/22A = 10.9 ohms

Magnetic Starter inductance =
10.9 ohms / (2*3.14*60Hz) = 0.029 Henry = 29mH. (Seems like a reasonable value of inductance for a beefy inductor.).