How can use this pcb header (rated voltage, nominal voltage etc.)


I am looking at the following PCB header for a 2-piece pluggable terminal block by Phoenix GMSTBVA 2,5/ 4-G-7,62 (pdf)

However regarding voltage there are several values in the datasheet and I couldn't quite find a completely consistent description what the difference is between them:

  • Rated voltage (III/3) 400 V
  • Rated voltage (III/2) 630 V
  • Rated voltage (II/2) 630 V

And then below under approvals I find:

  • CSA: Nominal voltage U_N: 300V
  • cULus Recognized: Nominal voltage U_N: 300V
  • VDE: Nominal voltage U_N: 400V

Are these values RMS AC or peak values. Are these for AC and DC? What is the difference between rated voltage and nominal voltage in this context?

Best Answer

These voltages are ratings for different scenarios like air clearance and creepage distances following IEC 60664-1:2007-04. The voltages are for AC and DC, I would use them as peak values.

The roman numbers are the rated impulse withstand voltage category, the normal numbers denote the pollution level.

Rated voltages are the maximum you could expect the connector to widerstand in defined conditions. Nominal voltages are for normal operation with a good safety margin. Since different countries have different understandings of safety, the local agencys like the VDE give different nominal ratings depending on the rated voltage.