The schedule of test results is where an EIC or EICR proves each circuit, and on the BS 7671:2018 model forms from A2:2022 onwards it runs to 31 numbered columns across two sheets: a schedule of circuit details (columns 1 to 16) and a schedule of test results (columns 17 to 31). The A4:2026 model forms keep that layout and blank copies are free from the IET. This guide walks the columns in order, shows where each figure comes from and what it gets compared against, and works two examples, a 2.5/1.5 mm² ring final and a Zs temperature correction, so you can sanity-check your own readings on site.
- Columns 1 to 16 describe the circuit; columns 17 to 31 hold the results. Every result column has a reference value somewhere in BS 7671, and the schedule is only useful if you know what that reference is.
- Column 12 (maximum permitted Zs) defaults to the Chapter 41 tabulated value. Your measured Zs in column 27 is taken cold, so apply the 0.8 rule of thumb or use the corrected On-Site Guide tables before comparing.
- Ring final readings follow a pattern. On 2.5/1.5 mm² cable the cross-connected readings should be flat around the ring; on 4.0/1.5 mm² they rise towards the middle, and that is not a fault.
- RCD testing since A2:2022 is one AC test at IΔn: 300 ms maximum for a general RCD, 130 to 500 ms for an S-type. The five-times test is optional and doesn't go on the schedule.
- Test voltage and minimum insulation resistance come from Table 64: 250 V DC and 0.5 MΩ for SELV/PELV, 500 V DC and 1 MΩ for everything up to 500 V.
- Blank cells are the enemy. Use N/A, LIM or a Remarks note so the next inspector can tell a test that didn't apply from a test you forgot.
What goes in the board details at the top?
Before the columns start, the top of each sheet asks for the distribution board's designation and location, what supplies it and the overcurrent protective device on that supply, so the next person can find the board and understand what it hangs off. It also asks for the type of any surge protective device fitted (T1, T2 or T3) and whether its status indicator shows it is healthy. Not every SPD has a visible indicator, so record what you can see.
Then come the measured values at the board: earth fault loop impedance at the distribution board (Zdb) and prospective fault current (Ipf). Ipf is the higher of the prospective short-circuit current (L–N) and the prospective earth fault current (L–E) at that board. On a single-phase supply measure both and record the higher; on a three-phase board the line-to-line value is commonly taken as twice the single-phase figure, which is the approach in the IET On-Site Guide. Confirm correct polarity and, where it applies, phase sequence, then record the serial or asset numbers of each instrument used along with the tester's name, signature and date. The instrument numbers matter more than people think: they tie a reading to a calibration certificate, and a scheme assessor will ask. Guidance Note 3 recommends instruments that meet BS EN 61557, which for a continuity ohmmeter means a test current of at least 200 mA and an open-circuit voltage between 4 and 24 V.
Circuit details: columns 1 to 16
| Column | What goes in |
|---|---|
| 1–2 | Circuit number, and a description the next person can match to the board labels. |
| 3 | Type of wiring, as the letter code from the key on the form: A for thermoplastic insulated and sheathed cable through to H for mineral insulated, or O for anything else, described in Remarks. |
| 4 | Reference method, from Table 4A2 in Appendix 4 of BS 7671. Clipped direct is method C; twin-and-earth in a stud wall with thermal insulation is often 100 or 101. |
| 5 | Number of points served. Count what you can verify, and note any LIM sampling in Remarks. |
| 6–7 | Live and cpc conductor cross-sectional areas in mm². |
| 8–11 | The overcurrent protective device: BS EN number, type, rating in amps and short-circuit breaking capacity in kA (6 kA for most domestic BS EN 60898 devices). |
| 12 | Maximum permitted Zs. By default the tabulated value from Chapter 41; if you use another source, name it in Remarks. |
| 13–16 | The RCD: BS EN number, type (AC, A, F or B), rated residual operating current (IΔn) in mA, and rating in amps. |
Two details trip people up here. Column 11 asks for the device's rated short-circuit capacity, not the Ipf you measured; for a BS EN 60898 MCB that is the number in the rectangle on the front, typically 6000 or 10000. And column 13 wants the RCD's own standard, which for an RCBO is BS EN 61009 and for a stand-alone RCCB is BS EN 61008, not the standard of the MCB it happens to sit behind. The RCD type in column 14 is worth getting right too: A2:2022 restricted Type AC devices, so an EICR that records Type AC on a circuit with electronic loads is flagging something the next inspector will want to see.
Ring final circuit continuity: columns 18 to 20
Record the end-to-end resistance of the line (r1), neutral (rn) and cpc (r2) with the ends disconnected at the board. Line and neutral are the same size and length, so their readings should match closely; on 2.5/1.5 mm² twin-and-earth, r2 should be roughly 1.67 times r1 because 1.5 mm² copper is 12.10 mΩ/m against 7.41 mΩ/m for 2.5 mm² at 20 °C.
A worked example makes the pattern easy to check. A 70 m ring in 2.5/1.5 mm² gives r1 ≈ 0.52 Ω, rn ≈ 0.52 Ω and r2 ≈ 0.85 Ω. Cross-connect line and neutral and measure at every socket: each reading should be close to (r1 + rn) ÷ 4, about 0.26 Ω, and substantially the same all the way round. Then cross-connect line and cpc and repeat: each reading is the R1+R2 to that socket, close to (r1 + r2) ÷ 4, about 0.34 Ω, again flat around the ring. A spur shows as a slightly higher reading at its own socket, which is fine, and a reading that climbs steadily is the sign of a break or a cross-connected socket.
Rings in 4.0/1.5 mm² cable behave differently. The IET's 2022 analysis showed that with unequal line and cpc sizes the line-to-cpc readings rise towards the mid-point of the ring and fall back towards the board, with the highest reading, at the mid-point, still matching (r1 + r2) ÷ 4. If the end-to-end and line-to-neutral steps look right, don't read that pattern as a fault. Radial circuits leave these columns blank or N/A and use columns 21 and 22 instead. Our ring final circuit testing guide covers the method step by step: Ring Final Circuit Testing: r1, rn, r2 and R1+R2 Explained
Continuity: columns 21 and 22
Enter R1+R2 or R2, whichever you measured. R1+R2 is the usual figure for a final circuit with the line and cpc temporarily linked at the board and measured at the furthest point; R2 on its own is used where the cpc is measured separately, for example a steel conduit or a bonding conductor. Null your leads first, and if your instrument doesn't do that, subtract the lead resistance. Never derive R1+R2 by taking Ze away from a measured Zs: the IET points out that parallel paths through bonding and metalwork usually make measured Zs lower than Ze plus R1+R2, so the subtraction gives an optimistic number. The full method is in our R1+R2 continuity guide: Continuity Testing: R1+R2 Method, Wander Lead and Values
Insulation resistance: columns 23 to 25
Record the test voltage in column 23, then the live-to-live and live-to-earth readings in MΩ. Table 64 in BS 7671 sets both the voltage and the pass mark, as the table below shows.
| Circuit nominal voltage | Test voltage (DC) | Minimum insulation resistance |
|---|---|---|
| SELV and PELV | 250 V | 0.5 MΩ |
| Up to and including 500 V, including FELV | 500 V | 1.0 MΩ |
| Above 500 V | 1000 V | 1.0 MΩ |
A schedule that accompanies an EIC must show results at the Table 64 voltage. On an EICR you have more latitude, and the IET's advice for circuits feeding vulnerable equipment is to test only between the live conductors joined together and earth, which is why column 24 sometimes carries LIM with a note. Disconnect surge protective devices, and anything else likely to be damaged or to pull the reading down, before you test, and list what you disconnected in Remarks. BS 7671 also notes that where a whole-installation reading is under 2 MΩ a latent defect may exist and each circuit should be tested separately; anything below 1 MΩ to earth is a C2 in Best Practice Guide 4. Your instrument will read 999 MΩ or ">200 MΩ" on a healthy circuit, and it is fine to record the over-range figure the display gives. If a reading is low, our low insulation resistance troubleshooting guide is the place to start: Low Insulation Resistance: Finding the Fault on Site
Polarity: column 26
Tick when polarity is correct at every point tested: single-pole devices in the line conductor only, centre contact of Edison screw lampholders on the line, and socket outlets wired correctly. A schedule that goes with an EIC cannot show incorrect polarity, because an EIC certifies that the work complies, so put it right before you certify. On an EICR, reversed polarity at a socket is a C2 and reversed polarity at the origin is a C1 under Best Practice Guide 4. See Polarity Testing Explained: Checks, Methods and EICR Codes for the full test sequence.
Maximum measured Zs: column 27
This is the highest earth fault loop impedance on the circuit, normally at the furthest point. BS 7671 lets you measure it or determine it another way, and Ze plus the circuit's R1+R2 is the standard calculation. The IET's May 2025 Wiring Matters article on live testing calls earth fault loop impedance the live test most often carried out unnecessarily at initial verification, so on an EIC calculating it is not a shortcut, it is the recommended route, with a measurement at the origin and a sample of circuits to confirm.
Whichever way you get the figure, correct for temperature before comparing it with column 12. The Chapter 41 maximums assume conductors at their operating temperature, commonly 70 °C, and circuits are rarely that warm when you test them. Appendix 3 of BS 7671 gives a rule of thumb of 0.8, and the tables in the On-Site Guide and Guidance Note 3 already have it built in. A worked example: a 32 A Type B MCB to BS EN 60898 on a 0.4 s circuit has a Chapter 41 maximum of 1.37 Ω. Multiply by 0.8 and the cold limit is 1.10 Ω, which is the figure you will find in the On-Site Guide. A measured 1.20 Ω looks like a pass against column 12 and is a fail once corrected. For readings sitting near the limit you can do a more precise correction from the actual ambient temperature and conductor resistance. Column 12 and column 27 are compared on our maximum Zs tables page, Maximum Zs Values BS 7671: Tables, 80% Rule and Ze, and if the reading is higher than it should be, High Zs Readings: Causes, Checks and How to Fix Them works through the causes.
RCD: columns 28 and 29
Record the disconnection time in milliseconds from an alternating current test at the RCD's rated residual operating current (IΔn), whatever the RCD type. A general non-delay RCD must operate within 300 ms and an S-type time-delayed RCD between 130 ms and 500 ms. Since A2:2022 the test at five times IΔn is no longer required, and while your instrument will still offer it and it can help when fault-finding, the schedule wants the IΔn figure. The IET's July 2022 Wiring Matters explains the change. Tick column 29 when the integral test button trips the device; that is a functional check, not a substitute for the instrument test. Test with downstream loads disconnected where you can, because the IET notes that electronic equipment and long circuits can affect the result and that many reported RCD test failures turn out to be user error. Our RCD testing guide has the test sequence and the type-specific notes: RCD Testing Explained: Types, Test Currents and Trip Times
AFDD and Remarks: columns 30 and 31
Tick column 30 when the AFDD's manual test button works. Not every AFDD has one, and the model form says so, so record N/A rather than leaving it empty. Regulation 421.1.7 and where AFDDs are required is covered at AFDD Requirements: Regulation 421.1.7 Explained.
Remarks is the column that stops a schedule being misread. Use it for equipment vulnerable to testing and what you disconnected, the source of any maximum Zs not taken from Chapter 41, details of a Type 3 SPD protecting sensitive equipment, the extent of any sampling on a large board, and anything you could not test with a LIM code and the reason. A remark like "IR L–E only, ring main 2, downstream electronic ballasts" takes ten seconds and saves the next inspector guessing.
What are the most common mistakes on a schedule?
| Mistake | Why it matters | What to do instead |
|---|---|---|
| Comparing a cold Zs with the uncorrected Chapter 41 value | Passes circuits that would fail at operating temperature | Apply 0.8 or use the OSG/GN3 tables |
| Working out R1+R2 as Zs minus Ze | Parallel paths make the answer optimistic | Measure R1+R2 directly |
| Insulation testing with SPDs or electronics connected | Low readings or damaged equipment | Disconnect and list in Remarks |
| Recording the five-times RCD result in column 28 | Wrong test since A2:2022 | Record the IΔn result |
| Reading uneven 4.0/1.5 mm² ring results as a fault | Normal for unequal conductor sizes | Check r1, rn and r2 first |
| Leaving cells blank | Untested and not-applicable look the same | Use N/A, LIM or a remark |
| Recording FI for a low IR reading | It isn't an investigation, it's a result | Code it C2 |
| Measuring Zs live on every circuit at initial verification | Unnecessary live working | Calculate from Ze + R1+R2, sample-verify |
The last two link to guidance elsewhere on this site: FI use is covered in EICR Observation Codes Explained: C1, C2, C3 and FI, and the difference between the schedule on an EIC and on an EICR in EICR vs EIC: What's the Difference? (and Minor Works).
How Certio helps
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