EARTH ELECTRODE / EARTH LOOP RESISTANCE CONTINUITY OF PE CONDUCTORS / CONDUCTIVE PARTS Nominal Differntial current I∆N (mA) 10 30 100 300 500 1000 R earth (Ω) max. (Uc<50 V) 5000 1666 500 166 100 50 R earth (Ω) max. (Uc<25 V) 2500 833 250 83 50 25 1 2 INSULATION RESISTANCE LINE / NEUTRAL TO PE 3 Limits: Where no RCD, select limit from the FUSE characteristics, test by Z loop. Where RCD: GUIDE THROUGH VERIFICATION ON LOW-VOLTAGE ELECTRICAL INSTALLATIONS : IEC 60364-6 PROTECTION BY AUTOMATIC DISCONNECTION OF THE SUPPLY 4 REPORTS AND CERTIFICATES ON LOW-VOLTAGE ELECTRICAL INSTALLATIONS: IEC 60364 5 TN system - Two clamps - clamps arround main N/PE cable TT system - Two wire - test from the socket N to PE IT system - Three wire - test leads to rods in triangle Lightning system & Earth loops - test each loop IEC 60364-6 61.3.6.2., B.3., equipment: IEC 61557-5 Limits: 2 Ω above ground 10 Ω whole system 10 Ω underground per leg or 8% of Specific Earth Resistance L1 L2 L3 PE TN N L1 L2 L3 PE N TT L1 L2 L3 PE N TT IEC 60364-6 61.3.2., equipment: IEC 61557- 4 Parameters: ±200 mA both directions, all exposed conductive parts to MPE and in between where distance < 2.5 m. Limits: or 2 Ω max. (where RCD built-in) R ≤ U c I pfc 50V 200A 0,25 Ω ≤ ≤ (where Fuse C20A built-in) IEC 60364-6 61.3.3., equipment: IEC 61557-2 Parameters: 500 V DC 250 V DC for PELV/SELV Limits on Circuits: R min > 1 MΩ R min > 0.5 MΩ for PELV/SELV Floor and wall resistance/impedance R > 50 kΩ (insulated) Semiconductive coatings 1 MΩ < R > 1 GΩ Protection against static electricity (EN 61340-5-1) Leakage Current - alternative method for testing and tracing insulation problems without disconnection Parameters: TRMS Low range measurement Limits: 1 mA/kW or 3.5 mA max. per app. 5 mA max. where heating app. 1/3 x Idn where RCD protected circuits. Leakage < 100 mA for fire protection. Fuse: Z loop L-PE / Z line L-L, L-N IEC 60364-6 61.3.6.3., 61.3.11., equipment: IEC 61557- 3 Parameters / Limits are characteristics of particular built-in Fuse, designed for trip-out time of: 0.1 s (Explosive), 0.2s (3Phase Circuits), 0.4 s (1Phase systems) or 5 s (fixed connections). Measured values of Impedances from the end of the circuit must be lower than Zs from the table. In (A) Tip B Tip C TiP G Ia = 5x In (A) Zs= ( Ω) (0,2 s) Ia= 10x In(A) Zs= ( Ω) (0,2 s) In (A) Zs= ( Ω) (0,4 s) 2 10 22 20 11 16 13,7 4 20 11 40 5,5 32 6,8 6 30 7,3 60 3,65 47 4,6 10 50 4,4 100 2,2 82 2,6 16 80 2,8 160 1,4 110 2,0 20 100 2,2 200 1,1 147 1,4 RCD: Trip out time, Trip out Current IEC 60364-6 61.3.6.1., 61.3.7., equipment: IEC 61557- 6 More Parameters/Limits could be found in Metrel Handbooks and inside Eurotest/Smartec testers. RCD RCD trip out at differential Id (ms) 1/2 x I∆N 1 x I ∆ N 2 x I ∆ N 5 x I ∆ N General No trip t∆ < 300 t∆ < 150 t∆ < 40 Selective No trip 130 x t ∆ < 500 60 x t ∆ < 200 50 x t ∆ < 150 RCD Slope range (from-to) 0,5 ÷ 1.0 x l ∆ N AC A 0,35 ÷ 1.4 x l ∆ N B 0,5 ÷ 2.0 x l ∆ N www. metrel.si