Guide · Updated October 2026
How to read the schedule of test results
The last pages of an EICR are a table of numbers for every circuit. Here is what each column means and what a pass looks like.
The columns you will see
| Column | What it measures |
|---|---|
| Circuit / OCPD | The circuit name and the protective device, for example B32 for a 32 amp type B breaker |
| R1+R2 | Resistance of the line and protective conductors end to end. Confirms the earth path is continuous. |
| r1, rn, r2 | Ring circuit continuity. The three loops of a ring should be connected all the way round. |
| IR | Insulation resistance in megohms. High is good. Below 1 MΩ on most circuits is a problem. |
| Polarity | Switches and fuses are in the line conductor, not the neutral. A tick means correct. |
| Zs | Earth fault loop impedance in ohms. Must be low enough for the breaker to trip quickly in a fault. |
| RCD ms | How fast the RCD disconnects at its rated current, in milliseconds. |
A worked example
CCT 3 KITCHEN SKT B32 2.5/1.5 T&E
R1+R2 0.31 Ω IR L-E >299 MΩ ✓
Zs 0.42 Ω max 1.37 Ω ✓
RCD 30 mA 21 ms ✓
R1+R2 0.31 Ω IR L-E >299 MΩ ✓
Zs 0.42 Ω max 1.37 Ω ✓
RCD 30 mA 21 ms ✓
The measured Zs of 0.42 Ω is well under the maximum of 1.37 Ω for a B32 breaker, so in a fault the breaker would trip quickly. Insulation resistance is above the range of the meter, which is the best possible result. The RCD tripped in 21 milliseconds, comfortably inside the limit.
Readings that cause concern
- Zs higher than the maximum for the device, which usually leads to a C2
- Insulation resistance below 1 MΩ, which often leads to an FI
- A ring circuit with a break, shown as unequal or missing r1, rn or r2 values
- An RCD that does not trip, or trips too slowly
Terms you do not recognise are explained in the electrical glossary.
FAQ
Questions
Why does my report say LIM next to some readings?
LIM means a limitation. The inspector could not take that reading, for example because a circuit could not be isolated. The reason should be recorded on the report.
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