1. Test method

1) ACB Close: Measurement between phases of main circuit

EUT’s contacts condition	Voltage applied to	Earth connected to	Remark
Closed	AaCc(Nn)	BbF	Phase

 

2) ACB OFF: Measure between poles of main circuit

EUT’s contacts condition	Voltage applied to	Earth connected to	Remark
Open	ABC(N)	abc(n)F	Pole

 

2.

When measuring ACB alone, 500 V should be applied to measure 100 ㏁ or more.

It is 10 ㏁ or more when measured as a whole switchboard

When measuring, there is no problem as long as you observe the measurement area according to the ACB Close/Off status.