Loop Impedance / Psc Tests; Principles Of Measurement - KYORITSU 6050 Instruction Manual

● Operating Errors of trip current (IEC 61557-6)
Function
×1/2
×1
×5
Auto Ramp
The influencing variations used for calculating the operating error are
denoted as follows:
Temperature : 0℃ and 40℃
Earth electrode resistance :
I n(mA)
100
300
500
1000
System voltage : 230V+10%-15%
Supply voltage : 8V to 13.8V

5. LOOP IMPEDANCE / PSC TESTS

5.1 Principles of Measurement

5.1-1 Measurement of Fault Loop Impedance and Prospective Fault
Current
If an electrical installation is protected by over- current protective devices
including circuit breakers or fuses, the earth fault loop impedance should be
measured.
In the event of a fault the earth fault loop impedance should be low enough
Operating error of trip current
-10%∼0%
0%∼+10%
0%∼+10%
-10%∼+10%
Earth electrode resistance(Ω)
UL50V
10
30
2000
600
200
130
80
40
table.1
― 12 ―
UL25V
2000
600
200
65
40
20