Induction motor question (Loring?)

[RodKirby]

My new BIG Drill Press has an Induction motor twice the size (physically), of the old one. However, the only spec different is AMPS 6.25 vs 5.2.

Other specs are identical:
HP 3/4
RPM 1420
KW .55
Phase 1
Pole 4

Aside from the "bigger is better", why such a big difference in mass?

[LCHIEN]

Do you mean bigger by volume, diameter, or by mass?
You say mass but I doubt you took the motor off and weighed them.
If you mean twice as big in diameter then it would be huge. But twice as big in volume might only be 25% bigger in each dimension (but might have twice the mass).
(see, these are the details an engineer wants).

I can't say exactly, with not that strong a practical motor background + the sketchy info, but my guesses would be:
1) increase in power was just enough - had to go to the next larger standard frame size
2) maybe this one is TEFC so it has to have more internal room (again, they come in standard frame sizes, maybe the next one was warranted)

I don't even know if frame sizes are standardized internationally, but I do know they are standardized, and my guess is that they go up by about 25-30% in diameter for each step.

So when do we get to hear the details on the new DP?

[RodKirby]

I did mean mass - I would say 50% larger diameter and 50% larger in length. I'm just guessing it would weigh twice as much. Old drill was around 90lbs new one 190lbs (more details later)

TEFC?

Waiting for some paint to dry - pics etc. tomorrow
(Had a busy - fun - week)

[LCHIEN]

I did mean mass - I would say 50% larger diameter and 50% larger in length. I'm just guessing it would weigh twice as much. Old drill was around 90lbs new one 190lbs (more details later)

TEFC?

Waiting for some paint to dry - pics etc. tomorrow
(Had a busy - fun - week)

totally enclosed - fan cooled.
Used in dusty environs. preferable for ww machinery but not always used for reasons of cost.

I usually describe things as bigger referring to either volume, girth, or length.
To me a more massive item would be described as heavier.

[RodKirby]

Sorry Loring - It IS (around) 50% larger in diameter and length - I guessed double the weight.

Dang! I have to learn to communicate betterer (sic)

[Stytooner]

You definitely have to keep your ducks in a row when discussing technical stuff with Loring.
That would be a straight row with no more than 12 ducks and none straying more than 5 degrees from the center line while maintaining no more than a 2.75" distance from the duck ahead for a minimum of 200 yards in broad daylight on a level field of bermuda grass in spring time while the Sun is shining and the air temperature is between 75 and 82.5 degrees F.

[LCHIEN]

You definitely have to keep your ducks in a row when discussing technical stuff with Loring.
That would be a straight row with no more than 12 ducks and none straying more than 5 degrees from the center line while maintaining no more than a 2.75" distance from the duck ahead for a minimum of 200 yards in broad daylight on a level field of bermuda grass in spring time while the Sun is shining and the air temperature is between 75 and 82.5 degrees F.

very good. Now you're getting the point!

[LCHIEN]

from Wikipedia:
Induction motors are the workhorses of industry and motors up to about 500 kW (670 horsepower) in output are produced in highly standardized frame sizes, making them nearly completely interchangeable between manufacturers (although European and North American standard dimensions are different).

I'm guessing Rod has a metric motor in a metric frame size.
runs on metric volts and metric frequencies .

I could only find one table in a quick search, looks like NEMA (US standard motors - Nat'l Elec. Manuf. Assn) frame sizes increase about 20-25% in diameter per frame size jump. Which as I pointed out earlier a 25% change in both girth and length would increase volume by 2X and mass is proprotional to volume assuming the same density.

I'm pretty sure therefore that the motor just jumped one frame size.
BTW, the HP that fits in a frame size will be similar but as they learn to make motors better, one co. may fit a more powerful motor in a smaller frame - a sales advantage. But there's no standard rules as to what HP fits in a given frame, just what an engineer can pack into a machine, naturally the market drives the smallest frame possible for most apps. although at the borderline a manufacturer might be able to sell the same HP in a larger frame for less money, in non-weight/size critical applications.

[Tom Slick]

Look for an IEC or spec. number on the plate. that would be the metric frame size. metric motors' frame specs aren't as defined as NEMA numbers so you can get wide variances in the physical dimensions with the other specs being the same.
I've had a 3ph 9hp metric motor in a frame that under NEMA would spec for a 2hp frame.

[LCHIEN]

Rod, after thinkin about it for a day, I'm now sure what it is.
The new DP motor was compared against larger horses. Maybe those Clydesdales they have on the beer commercials.

[LinuxRandal]

Couldn't it be different sizes, depending on how they rated it?

IE, some motors are rated by what they put out at their failure point, verses motors rating their standard running point?

Just a stupid question, as all the marketing changed and I remember hearing about it, when I was little.

[RodKirby]

Rod, after thinkin about it for a day, I'm now sure what it is.
The new DP motor was compared against larger horses. Maybe those Clydesdales they have on the beer commercials.

Now you point it out - it's obvious