What's new
What's new

Will a 115 kva generator power an 80HP (65kva) CNC lathe?

Garwood

Diamond
Joined
Oct 10, 2009
Location
Oregon
Thinking about picking up a newer diesel generator to back up my shop. If it will run my biggest machine I will buy it.
 
Thinking about picking up a newer diesel generator to back up my shop. If it will run my biggest machine I will buy it.

Slight overkill if it were for 24 X 7 X 365 no-grid operation. Steady load @ 75% is about the sweetest spot for the best tradeoff between fuel economy and wear amortization for best life-cycle cost.

Biggest machine will usually run well below its max, hence I call it overkill.

That said, an emergency or backup SHOULD err on the side of reserve power. The machine designed for is not likely to be the only load. Your useful life before major overhaul expectation is multiple years longer [1]. Loads are more likely to increase than diminish.

2C and "many" used-up gen-sets worth.

[1] Consolidated Electric 100 KVA. Marathon head, Continental Diesel inline 6, ~ 147 BHP. Typically 3 months before major overhaul pulling a 100 HP motor, no clutch to the compressor & other loads per-each of an "A2" liquid Oxygen plant run 24 X 6, all year @ 85 KVA, and about as steady-state as loads ever get.

I hope Continental is out of business. The f**kers worked HARD to earn it.

Buda, Waukesha/Hercules/Hollingsworth, Murphy, Caterpiggle, even screaming-meemie "DEE DEE" hand grenade or make-you-think-they-are-about-to-be had longer lives by far.
 
Roughing 1018 with cnmg 632's I can run 80% load for about 20 minutes at a time. Spindle startup with a 300 lb 16" Chuck and 200 lb part is pretty aggressive.

No gearbox, belt drive spindle, 0-3500 rpm
 
Roughing 1018 with cnmg 632's I can run 80% load for about 20 minutes at a time. Spindle startup with a 300 lb 16" Chuck and 200 lb part is pretty aggressive.

No gearbox, belt drive spindle, 0-3500 rpm

Diesel actually LIKE a decent load on 'em. Look up "wet stacking" and why a turbo Diesel can often be a better deal than normally-aspirated.

Startup was our biggest issue with the A2 plants, but only once a week. Dry board about a foot long, operator standing on a 5T truck tire, sheet of plywood atop, would push the breaker up with the board. It would trip, first 2 or 3 goes, underslung trailer under the 100 KVA would bounce, try to lift a wheel!

The main load on the 100 HP (416 Wye) motor was a directly-belted Chicago-Pneumatic PB-44 four-stage air compressor. A mere 120CFM. At 3,600 PSIG.

Once online, add 40 Ton Worthington reefer, 20 HP motor, then 5 HP caustic pump. Around 16 hours in, Vietnam's ambient temperatures, add a 5 HP Lox pump to fill cylinders.

You aren't (yet) in need of being set-up for field-mobile, tactical deployment, designed to prep Oxidizer for "Redstone" missiles, or (A1 plant) produce breathing oxygen to support forward-based USAF sorties, so will have a proper disconnect.

War isn't just "Hell". Sometimes it is a tad weird as well.

Young USAF Major, Bien Hoa AFB, driving around in a midnight-blue Chevie SS 396 El Camino lady-boy let's-pretend I'm a pick-up truck, Wide-oval redstripe Uniroyals.

Why TF was HE so privileged, land of the shabby M-151 alleged-Jeep or local Lambretta Franken-scooter tricyle bus and cargo trucks?

Answer came one day when I was over to Base Fuels cadging a coupla tons of LOX the USAF was kind enough to make surplus to breathing needs.

There he sat, approach end of the runway with a carpet padded pipe rack in the bed of the El Camino, radio headset on.

On radio cue, he revs up, dumps clutch, lays smoke and screaming rubber Hell down the empty runway.

He perfectly matches speed to the incoming U2 spylane, silent as death in cotton wool, by comparison the usual birds on that patch. U2 gently lays one no-wheels wing across the padded rack as they come slowly to a halt as if welded together.

Haul the wheels dropped on take-off outta the bed, re-attach, regular "tug" takes over, and done.

Major prolly pulled rank on an Airman First to GET that damned job!

And here I were, now and then as OD having to run 8 miles of guard posts in a Ten Ton tactical tractor, bobtail, for lack of a single ignorant jeep, spare.

One thing for sure. That big V8 Diesel going painfully up through the gears jest to git to a dog-trot?

Never had to worry I'd come up on a pair of guards both ASLEEP!

:D
 
It's not just about size, make sure that power is clean and smooth. Especially when the load changes.

Don't just take the generator salesman's word for it.
If there's a problem he is completely off the hook.


Make sure that the CNC manufacturer agrees and supports it.
 
What happens during switchover?

Many folks assume generator is everything but not so.

A client has 40 kw unit that somehow will not support a 4 ton hvac, all new equipment.

Takes time to spool up to speed after start then after voltage and frequency correct it switches line.

Usually in 30 seconds or so but a running machine looking primary power may not like that much.

High power ups one item.

Or do they have system in machine like ups that retains exact spot in program upon loss of power?

When power drops the tool stops in place, does it crash or does machine back off as it spins down?

We know nothing of the machines but backup power a fair bit.

First call should be as others suggested, to manufacturer to confirm how to design system.

Sent from my SAMSUNG-SM-G930A using Tapatalk
 
What happens during switchover?
I don't see Garwood planning a gen set even for automatic transfer, let alone UPS-SEAMLESS transition, a whole 'nuther level wanting flywheel or battery bank.

My take is that he would be planning in advance whether to bring up the machine on Diesel or mains and stay there until making another deliberate choice, all "manually", shut-down, later restart most of all.
 
I don't see Garwood planning a gen set even for automatic transfer, let alone UPS-SEAMLESS transition, a whole 'nuther level wanting flywheel or battery bank.

My take is that he would be planning in advance whether to bring up the machine on Diesel or mains and stay there until making another deliberate choice, all "manually", shut-down, later restart most of all.

Yup, not a job for an automatic transfer switch. Unless it is mandatory for all employees to drive a Tesla and all have their own charging setup at the plant and all are wired to backfeed the machines.
 
Yup, not a job for an automatic transfer switch. Unless it is mandatory for all employees to drive a Tesla and all have their own charging setup at the plant and all are wired to backfeed the machines.

Ah, well.. Telco pensioner & critical Fortune 100, 400, etc, nailed-up private networks as paid it, here.

"No break" // UPS power is a whole 'nuther level.

Hong Kong has the luxury (or curse) of two independent power cos'. Needless to say, more than a few of our data centre facilities are intentionally sited along their service boundaries. Separate entrances, opposite sides of the building, etc.

We can - and do - get two mains suppliers, then two sets of diesels, EACH, and as many as four separate battery banks and monster UPS rigs, a single site.

"Needless to say" the only unplanned, not seamless cutover, outage my Hong Kong servers ever had was from human error.

A rack monkey did the manual redundancy maintenance cutover bass-ackwards to procedure, the rack zone we were in. Killed-off a record attempt at "longest up time" at right around a mere thousand days in.

Not yet that close to the record. You'd have to know *BSD Unix on an underclocked Via C6 run fanless?

BFD. That server was only running the attempt for the fun in it.

But the Finance industry is what Hong Kong is about... so my old mates over to HSBC and Standard Chartered, Wing Lung, & c. were far more seriously pissed-off!

$$$$$$$$$$$$$

:(

"New China News Agency" which is "none of the above", as to their real function, wudda had their stealthy ears go deef too.

Buggers have had one or more servers in every facility on every wire in all of Asia since at least the first term of Slick Willie Cunton.

BFD. Easier for others to know whom listen to as well!

You'd have to know humans and the games that they play...

i i i i i
 
Roughing 1018 with cnmg 632's I can run 80% load for about 20 minutes at a time. Spindle startup with a 300 lb 16" Chuck and 200 lb part is pretty aggressive.

No gearbox, belt drive spindle, 0-3500 rpm


WOW!

80HP with a 16" chuck and no gearbox! :willy_nilly:
That's a combination!


-----------------

Think Snow Eh!
Ox
 
I really wonder what brand and model of CNC lathe that is.

With Garwood's background? Bit of a "hot rodder" ain't he?

Could be an 1898 Niles Tool Works 120-incher with a Bessemer hot-bulb engine the size of a two-car garage and twice as ugly?

Oh... and modern CNC controls.

Conjured up by Ox, of course...

Ox ever retires to breeding horses, they are like to have wings, tandem saddles, six legs, snow-traks for Antarctic use, and zero-zero visibility automatic landing systems.

You'd have to know "necessity" and clever Buckeye farm boys' conceptions of amusing ways to earn a crust...

:D
 
It's a Leadwell LTC-30 something or other. Motor says 65KW on it and it's the size of a small refrigerator laid on it's side. Standard was 40HP, but this one was ordered with extra oomph I guess. I don't know.

I wouldn't be switching automatically. No way.

I'm on a phase converter now and can barely run this lathe. I need to do a big power upgrade soon, but in order to do that my shop will be down for probably a few weeks at the minimum. All my machines run on a busway system so I was figgering I could run the generator into the far end of the busway and pull the fuses from the existing panel to run on gen power.

I just realized I wrote 65 KVA in the title instead of 65KW. Probably not too far off from one another, but it's 65KW spindle plus the hydraulics, control, servos and live tooling.

I think the generator I'm looking at will cover at. It's a newer Deere with a 6.8L inline 6
 
I'm on a phase converter now and can barely run this lathe.

Spindle startup with a 300 lb 16" Chuck and 200 lb part is pretty aggressive.

My lathes see the biggest amp draw upon starting the spindle. Actual amp draw during heavy cutting is still lower than when the spindle ramps up.

Check your spindle acceleration parameters. They are usually set to max throttle from the factory like under 1 second to full speed. Reducing the spindle acceleration by 2 or 4 seconds won't hardly be noticeable in added cycle time, but it will reduce power consumption a whole lot. The reduced load on the VFD will also make it live much longer as it's not working so hard.
 








 
Back
Top