G
gerard
Hi,
I have an industrial mixer at work that used to be powered by a dual speed motor. These particular motors are expensive and not always easy to get off the shelf in the event of a breakdown. I have replaced this a 4 pole single speed motor, controlled by an Inverter. The old motor was controlled with contactors and these contactors were in turn controlled by the machines PCB circuitry.
The motor drives a spiral - this spiral will only operate when the mixing bowl is in place and is no potential harm to an operator. When the mixing bowl is taken away by the operator, the spiral is exposed. Although the is minimal risk of harm, I would like to eliminate any risk whatsoever. I am going to install an inductive sensor that will detect when the bowl is in place, this sensor will then be used to enable the VFD to drive the motor. There are a few other conditions that have to be met for the machine to start so my extra sensor is not the only safety device. Would this be a suitable method of safely disabling the machine or is there a need for a safety relay? Has anybody any experience/suggestions on this? Is disabling a drive with a control signal acceptable or would I need a contactor to cut power to drive, hence stopping the motor?
Cheers
I have an industrial mixer at work that used to be powered by a dual speed motor. These particular motors are expensive and not always easy to get off the shelf in the event of a breakdown. I have replaced this a 4 pole single speed motor, controlled by an Inverter. The old motor was controlled with contactors and these contactors were in turn controlled by the machines PCB circuitry.
The motor drives a spiral - this spiral will only operate when the mixing bowl is in place and is no potential harm to an operator. When the mixing bowl is taken away by the operator, the spiral is exposed. Although the is minimal risk of harm, I would like to eliminate any risk whatsoever. I am going to install an inductive sensor that will detect when the bowl is in place, this sensor will then be used to enable the VFD to drive the motor. There are a few other conditions that have to be met for the machine to start so my extra sensor is not the only safety device. Would this be a suitable method of safely disabling the machine or is there a need for a safety relay? Has anybody any experience/suggestions on this? Is disabling a drive with a control signal acceptable or would I need a contactor to cut power to drive, hence stopping the motor?
Cheers