PDA

View Full Version : What does CAV mean-motor data plate?

SVS
10-17-2009, 11:42 AM
I'm working on a 60's era Italian built lathe/motor, and have not been able to translate one term on the motor data plate....CAV?

It looks like so:

220/220V PHZ3
GIRI 3400/1700
CAV 7/5
KW
Amps 18/13

Ok-It's a two speed motor, GIRI apparently means RPM, but what does CAV mean?

The spaces next to KW are blank, and the amp draw is too low to to equal 7 and 5 Kilowatts or even 7 and 5 horsepower. I've been making up acronyms, checked wiki and my conversion reference book but no luck so far.

Any guesses?

Scott

TGTool
10-17-2009, 12:36 PM
I'm just guessing here too, but since cavallo is horse (I think) wouldn't that be a natural for horsepower. I can't reconcile the current draw relationship unless it's just storytelling.

Lew Hartswick
10-17-2009, 12:48 PM
I would GUESS! that it is HP since the two speeds drop by 1/2 and the
current also drops that the HP drops also. BUT there must be some
other wiring "Gotchas".
HP is RPM x Torque if the torque does not increase by 2 when the
speed goes to 1/2, (and the current looks to drop, not double)
then .... ?????? :-) We need an Italian here. :-)
...lew...

lakeside53
10-17-2009, 01:07 PM
There are likely two separate winding sets (2 poles/4 pole), so that relationship does not hold...

And it's three phase, so don't forget the 1.73 factor when calculating power. and you can't get directly to hp without knowing the power factor / efficiency of the motor.

Without digging deeper, and given those currents, it's HP... and as it's Eupopean, a good chance it's delta wound.

rbjscott
10-17-2009, 02:14 PM
Is it a 50 cycle motor

SVS
10-17-2009, 05:39 PM
Thanks guys.

I was mistaken on a few volt and amp details-Fixed now.

The motor is 60 cycle, six wire, and double delta/wye for HI/LO speed.

The question is somewhat academic as I have the wiring figured out and running-It just turns out to not match my phase converter very well, being smaller than I was assuming. I'd always felt the motor was physically small for the supposed 5/7 HP or KW, but I'd never bothered doing the math till now.

Scott