Zs / R1+R2 Calculator
Calculate earth fault loop impedance (Zs = Ze + R1 + R2) from your test readings, or use the invertible mode to work backwards from a measured Zs and known Ze to find what R1+R2 must be. Handy for quick on-site sanity checks before referring to the full BS 7671 tables.
Zs / R1+R2 Calculator
Enter Ze, R1 and R2 to calculate Zs.
Zs = 0.000 Ω
Always check this against the maximum permitted Zs for the protective device in use (BS 7671 tables).
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