Which is the culprit

Status
Not open for further replies.

Sahib

Senior Member
Location
India
Is the capacitor switching or the series arcing in main neutral that causes high voltage transients to damage electronics? Thanks.
 

Sahib

Senior Member
Location
India
An automatic power factor correction panel with contactors, a main power distribution panel with series arcing main neutral and an electronic equipment. The contention from the electronic equipment installer was the electronic equipment was damaged due to high voltage transients generated by switching of capacitors by contactors. My contention is no over voltage transient is possible in a capacitive circuit as in an inductive circuit and so the series arcing main neutral in the main power distribution panel was the cause.
 

Smart $

Esteemed Member
Location
Ohio
An automatic power factor correction panel with contactors, a main power distribution panel with series arcing main neutral and an electronic equipment. The contention from the electronic equipment installer was the electronic equipment was damaged due to high voltage transients generated by switching of capacitors by contactors. My contention is no over voltage transient is possible in a capacitive circuit as in an inductive circuit and so the series arcing main neutral in the main power distribution panel was the cause.
Most believe capacitors create no more voltage transient than the voltage they are supplied with. However, when cut off by a switch [contactor], they can retain the supply voltage at that instance. When reconnected, the supply voltage at that instance may differ [nominally] by up to 2 times the nominal AC L-L voltage times the square root of 2 (i.e. maximum swing of instantaneous voltage).

That said, if you use double-throw contactors, you can connect bleed-off resistors to the OFF-state contacts to discharge the capacitors.
 

robbietan

Senior Member
Location
Antipolo City
Is the capacitor switching or the series arcing in main neutral that causes high voltage transients to damage electronics? Thanks.

have measured auto switching capacitors making transients that would affect (and shut down) the PLC of air conditioning controls
 
Status
Not open for further replies.
Top