21-09-2016, 07:04 PM
Hi peter
Yes they can be large source of RFI witch i had forgotten about butt the newer ones involve ways to reduce/ eliminate it.
when we install VSDs in the workplace we run shielded cable form the VSD to the motor and try keep it as short as possible, we also do some extra earthing. i have not had anything affected by a VSD RFI wise but i might take the 817 into the plant room and have a scan around and see.
At trade school we ran an ac motor down to 15hz! very very slow not recommended but it defiantly worked. The other advantage with a VSD is you wont loose torque unlike other reduced voltage (ac) starters.
Not sure exactly on what they do to the waveform but they reduce the sin-wave by chopping it similar to pwm. I believe something like this http://s.hswstatic.com/gif/dimmer-switch-diagram-6.gif
There are other options with ac motors or even dc motors just food for thought
Hope i have helped in some way
Matt
Yes they can be large source of RFI witch i had forgotten about butt the newer ones involve ways to reduce/ eliminate it.
when we install VSDs in the workplace we run shielded cable form the VSD to the motor and try keep it as short as possible, we also do some extra earthing. i have not had anything affected by a VSD RFI wise but i might take the 817 into the plant room and have a scan around and see.
At trade school we ran an ac motor down to 15hz! very very slow not recommended but it defiantly worked. The other advantage with a VSD is you wont loose torque unlike other reduced voltage (ac) starters.
Not sure exactly on what they do to the waveform but they reduce the sin-wave by chopping it similar to pwm. I believe something like this http://s.hswstatic.com/gif/dimmer-switch-diagram-6.gif
There are other options with ac motors or even dc motors just food for thought
Hope i have helped in some way
Matt