Impedance, differential time and tripping current test, earth resistance meter calibration
EPTIS ID: 882562
PT scheme / program name: Electrical calibration
PT item type: Electrical safety
Sample / item: multifunctional measuring instrument
Model / type: Metrel MI 3100 SE
Reference Laboratory: ISO IEC 17025 accreditated laboratory or NMI
Impedance measurement
1. Z LINE: line impedance phase-neutral / phase (METREL MI 3100 s)
2. Z LOOP: impedance of the fault loop phase / earth (METREL MI 3100 s)
3. Zs rcd: impedance of the fault loop with low test current (METREL MI 3100 s)
Measurement points:
| UUT setting | Nominal measurement points |
|---|---|
| Z line | (0.50, 1.80, 5.00, 50.0, 100.0, 180) Ω |
| Z loop | (0.50, 1.80, 5.00, 50.0, 100.0, 180) Ω |
| Zs rcd | (0.50, 1.80, 5.00) Ω |
Reference Laboratory CMC:
| Value | CMC |
|---|---|
| 0.50 Ω | 8 mΩ |
| 1.80 Ω | 18 mΩ |
| 5.00 Ω | 30 mΩ |
| 50.0 Ω | 0.39 Ω |
| 100.0 Ω | 0.50 Ω |
| 180 Ω | 1.0 Ω |
Differential tripping time (RCD t) and current (RCD I)
Measurement points:
Trip Out time (RCD t)
| UUT setting | Nominal measurement points |
|---|---|
| 10 mA X1 – AC – 0°- general non delayed | 300 ms |
| 30 mA X1 – AC – 0°- general non delayed | (150, 300) ms |
| 300 mA X1 – AC – 0°- general non delayed | (150, 300) ms |
| 30 mA X1 – AC – 180°- general non delayed | 300 ms |
| 30 mA X1 – AC – 0°- Selective | 390 ms |
| 30 mA X2 – AC – 0°- general non delayed | 150 ms |
| 30 mA X5 – AC – 0°- general non delayed | 40 ms |
| 500 mA X5 – AC – 0°- general non delayed | 20 ms |
Trip Out current (RCD I)
Execution of the points in the table to 20 ms (Trip out time reference)
| UUT setting | Nominal measurement points |
|---|---|
| 10 mA – AC – 0° – general non delayed | 10 mA |
| 30 mA – AC – 0° – general non delayed | 30 mA |
| 1000 mA – AC – 0° – general non delayed | 1000 mA |
| 30 mA – AC – 180° – general non delayed | 30 mA |
Reference Laboratory CMC:
| Value | CMC |
|---|---|
| RCD trip Time | 0.020 % rdg + 0.25 ms |
| RCD trip Current | 1.0 % rdg |
Measurement of earth resistance value
Measurement points and Reference Laboratory CMC:
| Value | CMC |
|---|---|
| 0.10 Ω | 5.0 mΩ |
| 1.0 Ω | 10 mΩ |
| 10 Ω | 60 mΩ |
| 100 Ω | 0.50 Ω |
| 900 Ω | 5.0 Ω |
Note: Indications regarding organizational methods, presentation and sending of results will be reported in the PT participation protocol
Scheduled start date for PT: every year in September
Payment: bank transfer