Current Ratio for Electromagnetic Brake

[gsjhand]

Hello

Can anybody explain to me that what current ratio means in electromagnetic brakes? I have device list for one of the projects which have brake for lifting drive with current ratio=4.

 

[sreid]

Possibly pull-in/drop-out current or voltage.

 

[oftenlost]

I would tend to agree with sreid. The current to cause the brake to move would be much greater than the holding current after the brake has activated. An example of this would be the undervoltage trips utilized in electromagnetic circuit breakers. A 115 volt undervoltage trip mechanism will not normally engage until 75 to 85 percent voltage is applied. As the voltage is lowered during test, this trip will normally remain engaged until the applied voltage drops to 10-15% of rated voltage due to the proximity of the magnetic shoes.