Reply to thread

Message

<blockquote data-quote="Troubleshooter" data-source="post: 740014">A 480 V, 3 hp 3-phase motor to lift and lower a conveyor bed has a rectifier attached to the inner windings of the motor. The rectifier, when energized creates 208 V DC to release the brake mounted to the non-working end of the motor.When we lift the conveyor bed, the brake functions and stops the travel timely/immediately.When we lower the conveyor bed and stop applying control voltage, the bed continues to lower, sometimes braking, sometimes lowering all the way to the ground too hard.Is the induction motor capable of inducing enough voltage or power to keep the rectifier back-fed and subsequently applying release voltage to the brake? If I mechanically override the brake while the bed is raised, and release the override, the brake instantaneously stops the lowering of the conveyor bed, suggesting the opening of the motor control circuit isn&#039;t removing all of the voltage, or it&#039;s coming from another source like induction.</blockquote>

[QUOTE="Troubleshooter, post: 740014"] A 480 V, 3 hp 3-phase motor to lift and lower a conveyor bed has a rectifier attached to the inner windings of the motor. The rectifier, when energized creates 208 V DC to release the brake mounted to the non-working end of the motor. When we lift the conveyor bed, the brake functions and stops the travel timely/immediately. When we lower the conveyor bed and stop applying control voltage, the bed continues to lower, sometimes braking, sometimes lowering all the way to the ground too hard. Is the induction motor capable of inducing enough voltage or power to keep the rectifier back-fed and subsequently applying release voltage to the brake? If I mechanically override the brake while the bed is raised, and release the override, the brake instantaneously stops the lowering of the conveyor bed, suggesting the opening of the motor control circuit isn't removing all of the voltage, or it's coming from another source like induction. [/QUOTE]

Name

Verification