Slow 2t22 rise by wiring motor to 480V on 240V supply?

[Robert Gift]

Immediately after start-up of the three-phase 2t22 motor, I'm too scared to switch open one leg of three-phase power to slow the rise.

So, can I safely run the motor undervoltaged?

The coils are connected for 208-240 operation on the 240 power we have.

What if I reconnect the coils for 480 V input on the 240V supply?

Thanks for your ideas.

[q2bman]

You're worrying me Robert. Sounds like something's going to get hot! I don't know though. I've ran 12 Volt sirens on 6 Volts no problem. A bit smaller in scale!

[Gil]

Yeah, the idea doesnt sound very safe. Whats wrong with the current windup?

[Robert Gift]

Wind up is a little too fast! As though motor is too powerful for load.

Internal heat is a concern, but for only 3 minutes should not be a problem.

I presume that I am merely reassigning coils in parallel on 208-240 into series for 480 V.
Would love to see a schematic of a dual-voltage three-phase motor.

[azman798]

Not to sound mean, but why does it matter that it winds up to fast? 8)

[Robert Gift]

Go ahead and sound mean. It's OK
But you don't sound mean. Your's is a perfectly legitimate question.

I don't like the way the siren speeds up so quickly.
For Attack, I'd like it to speed up a little slower, more like the speed at which it descends.

If it is safe to accomplish, I can easily rewire the motor for 480 volts.

Many three-phase motors are 208-240/480 volts.
It's just a matter of reassigning terminal jumpers.

[JasonC]

So, can I safely run the motor undervoltaged?

No, you'll burn the motor completely up. Besides, the thing would barely crawl up to well under half speed.

[Robert Gift]

Jason, since the load is not that great, would the motor attain full speed 3450 rpm (determined by 60 Hz power) but attain that speed at a slower rate?
Why would/could it burn out?

[Gil]

If it is safe to accomplish, I can easily rewire the motor for 480 volts.

Don't fall into the digester!

[Robert Gift]

Yes. That would be embarrassing.

Lassie is in this sewage treatment plant on the south edge of the main disgester: This photo taken before her transplant.
http://maps.live.com/default.aspx?v=2&c ... &encType=1

(This view is looking east.) You can see my fire station above (east)
Switch is in the little laboratory building with white roof.

If one falls into the main digester, they would disappear into the bottom of the 12' deep pool.
One cannot swim in the water full of tiny bubbles from pipes at the bottom.
The bubbles oxygenate and stir the "liquor" helping the microorganisms digest the sewage.
A body would slowly decompose and digest. All that would remain is skeletal bones on the bottom of the pool never discovered unless the pool were to be drained.