cupoftea
Advanced Member level 5
Hi,
We have an EV chargepoint which fails EMC.
AYK, Its pretty much a relay on a stick.
It has an internal SMPS, but its a bought-in one with approvals.
We have X capacitors on mains exit and entry points.
We have Y capacitors to earth on entry and exit points (from line and neutral)
The mains line and neutral are tracked closely with each other.
So can we at least say that the fail couldnt be anything to do with the mains?....anyway after all, during the EMC test, the chargepoint is not actually loaded on its mains output.
If the failure was to do with mains, then it represents a failure of the standards, as its easy to see that such a bit of kit could not cause any harm/damage/malfcuntion to anyone/anything?
So our failure must be to do with the switching edges of the comms lines?
Can you think of any more ways than the below to solve this EMC issue?
1...Use shielded comms cables
2....Use common mode chokes at the comms line entry positions.
3.....slow down the transmission frequencies as much as possible, and use comms protocols where the switching edges are deliberatley damped....by the way, what are those comms protocols wherein the bit edges are damped (slowed up) for EMC reasons?...there must be such a comms protocol?
4....Good PCB routing of the comms go's and returns?
What/how, could our EMC failure do to possibly damage/cause harm to anything in the outside world around it?
We have an EV chargepoint which fails EMC.
AYK, Its pretty much a relay on a stick.
It has an internal SMPS, but its a bought-in one with approvals.
We have X capacitors on mains exit and entry points.
We have Y capacitors to earth on entry and exit points (from line and neutral)
The mains line and neutral are tracked closely with each other.
So can we at least say that the fail couldnt be anything to do with the mains?....anyway after all, during the EMC test, the chargepoint is not actually loaded on its mains output.
If the failure was to do with mains, then it represents a failure of the standards, as its easy to see that such a bit of kit could not cause any harm/damage/malfcuntion to anyone/anything?
So our failure must be to do with the switching edges of the comms lines?
Can you think of any more ways than the below to solve this EMC issue?
1...Use shielded comms cables
2....Use common mode chokes at the comms line entry positions.
3.....slow down the transmission frequencies as much as possible, and use comms protocols where the switching edges are deliberatley damped....by the way, what are those comms protocols wherein the bit edges are damped (slowed up) for EMC reasons?...there must be such a comms protocol?
4....Good PCB routing of the comms go's and returns?
What/how, could our EMC failure do to possibly damage/cause harm to anything in the outside world around it?
