Hi.
This is in line with my previous post but I just made a new one to further discuss back EMF. I have been reading quite a number of articles about back EMF as one major reason of damaging PLC output, among others.
I have attached a pdf file on this thread. It is divided into 2 parts, 1st is the distribution panel diagram, the 2nd is the power & control diagram of compressor 1. As they say, inductive components like motor winding resist sudden changes in current. That's because the magnetic field caused by the current needs time to build up or decrease. That means that when current is flowing and this is suddenly cut off, the winding will try to maintain that current, and becomes a power source generating a voltage to be able to do so. It gets its power form the built up magnetic field.
In my diagram 1, I have drawn a distribution panel containing 2 3-phase compressors, 5 1-phase outlets & a PLC. Please take note that this is only an example & not exactly what is connected on site. On diagram 2, I have described the forward EMF when the compressor is still working. If ever they shutdown the main CB while compressor 1 is still on, there would be a back EMF coming form the its motor. I was just wondering how this will possible damage the PLC? and what will be the path of the back EMF since the MC is surely open?
This is in line with my previous post but I just made a new one to further discuss back EMF. I have been reading quite a number of articles about back EMF as one major reason of damaging PLC output, among others.
I have attached a pdf file on this thread. It is divided into 2 parts, 1st is the distribution panel diagram, the 2nd is the power & control diagram of compressor 1. As they say, inductive components like motor winding resist sudden changes in current. That's because the magnetic field caused by the current needs time to build up or decrease. That means that when current is flowing and this is suddenly cut off, the winding will try to maintain that current, and becomes a power source generating a voltage to be able to do so. It gets its power form the built up magnetic field.
In my diagram 1, I have drawn a distribution panel containing 2 3-phase compressors, 5 1-phase outlets & a PLC. Please take note that this is only an example & not exactly what is connected on site. On diagram 2, I have described the forward EMF when the compressor is still working. If ever they shutdown the main CB while compressor 1 is still on, there would be a back EMF coming form the its motor. I was just wondering how this will possible damage the PLC? and what will be the path of the back EMF since the MC is surely open?