Once you bypass the ATV you are losing its best feature - to regulate motor speed.
But I can understand the use of ATV only for starting high-torque applications, like mills, up-hill conveyors, crushers, mixers, etc.
Well, ATV is not so easy to bypass because there is energy conversion AC-->DC-->AC. The most sensitive is the ATV output. Therefore the bypass is possible only if you disconnect ATV output from the motor before connecting motor to mains using a bypass element (contactor for instance). Take this sequence seriously because if ATV output gets connected to mains, short circuit in ATV occurs. Therefore the best idea is to use ATV output contactor with additional mechanical and electrical interlock between ATV output contactor and bypass contactor. After bypass activation, ATV input side can remain connected to AC mains or can be disconnected, it is fully optional.
1. Connect ATV to mains and to motor
2. Start the motor.
3. When motor achieves full speed, activate freewheel stop (to avoid output phase loss on ATV if output contactor gets open)
4. Switch off ATV output contactor
5. Switch on bypass contactor
6. Optionally you can switch off ATV from mains, move it to garage or sell it.
But I can understand the use of ATV only for starting high-torque applications, like mills, up-hill conveyors, crushers, mixers, etc.
Well, ATV is not so easy to bypass because there is energy conversion AC-->DC-->AC. The most sensitive is the ATV output. Therefore the bypass is possible only if you disconnect ATV output from the motor before connecting motor to mains using a bypass element (contactor for instance). Take this sequence seriously because if ATV output gets connected to mains, short circuit in ATV occurs. Therefore the best idea is to use ATV output contactor with additional mechanical and electrical interlock between ATV output contactor and bypass contactor. After bypass activation, ATV input side can remain connected to AC mains or can be disconnected, it is fully optional.
1. Connect ATV to mains and to motor
2. Start the motor.
3. When motor achieves full speed, activate freewheel stop (to avoid output phase loss on ATV if output contactor gets open)
4. Switch off ATV output contactor
5. Switch on bypass contactor
6. Optionally you can switch off ATV from mains, move it to garage or sell it.
Gepubliceerd voor:Schneider Electric Belgium
