Motor With No Load ?

[crossman]

Well, the OP didn't specify what type of motor. My first assumption was a standard 60Hz induction motor like 97% of the motors out there. I agree that those certain type DC motors have an overspeed issue. However, I still stand by my original statement:

Every year the earth's orbit decays somewhat and we get a teeny bit closer to the sun. The earth will eventually get close enough to the sun so that the motor will burn up.

 

[1stYearElectrican]

Refering to the Motor with no load, it is labeled a Runaway motor. It is a Dc Series motor that has no natural speed limit and keeps building up and up then at this point there no ashame in running away to hide.:grin:

~FyE~

 

[masterelect1]

I know you can burn one up pretty quick running it real slow off a VFD for long periods of time if it doesn't have external cooling.

Unless it is inverter duty rated

 

[quogueelectric]

What is the technical term to describe the condition in which a motor will eventually burn itself up in the event that it continues to run with no load?

A firepump with the water valve shut off in a fire.

 

[weressl]

What is the technical term to describe the condition in which a motor will eventually burn itself up in the event that it continues to run with no load?

The only one that I know of is a canned pump. The canned pump is a motor-pump combination equipment that relies on the pumped material(liquid) to provide lubrication to the seals and the moving material to act as a heatsink to carry away the winding heat. So when it runs dry, it will eventually burn up. I believe though that the bearings will fail before before the winding would burn up, in most cases.

 

[masterelect1]

Refering to the Motor with no load, it is labeled a Runaway motor. It is a Dc Series motor that has no natural speed limit and keeps building up and up then at this point there no ashame in running away to hide.:grin:

~FyE~

Very good and correct answer- this also applies to a compound wound DC motor if the shunt field opens. street cars - at least here in Baltimore were series wound which gave excellent speed control as well as very good torque
capability; and there was 0 chance of the motor ever operating under a no load condition.