# Cable and installation method Source: https://meptools.com/tools/voltage-drop-cable-checker/docs/cable-and-installation/ Stage **02 Cable selection**, section **Cable and table**, chooses the physical cable and its installation from the **BS 7671 Appendix 4** tables. All cables in the catalog are **copper**. ## Cable construction A select of the 11 BS 7671 Appendix 4 cable families available in the catalog: | Family ID | Title | | --------- | ----------------------------- | | 4D1 | Single-core PVC non-armoured | | 4D2 | Multicore PVC non-armoured | | 4D3 | Single-core PVC armoured | | 4D4 | Multicore PVC armoured | | 4D5 | Flat twin and earth PVC | | 4E1 | Single-core XLPE non-armoured | | 4E2 | Multicore XLPE non-armoured | | 4E3 | Single-core XLPE armoured | | 4E4 | Multicore XLPE armoured | | 4F1 | Flexible thermosetting 60°C | | 4F2 | Flexible thermosetting 90°C | All families are copper conductor. ## Supported installation method A select listing only the installation methods valid for the chosen cable family, each shown as **"‹reference method› · ‹label›"**. Full method catalog (id → label → BS 7671 reference method): | ID | Label | Reference method | | -------- | -------------------------------------------------- | ---------------- | | 1 | In conduit in a thermally insulated wall | A | | 2 | Multicore in conduit in a thermally insulated wall | A | | 4 | In conduit on a wall | B | | 20 | Clipped direct | C | | 23 | Multicore on perforated tray | E | | 32 | Single-core on ladder or cleats | F | | 35 | Single-core spaced in free air | G | | 70 | In buried duct | D1 | | 72 | Buried direct | D2 | | 100 | T&E under insulation up to 100 mm | 100 | | 101 | T&E under insulation over 100 mm | 101 | | 102 | T&E touching inner wall | 102 | | 103 | T&E not touching inner wall | 103 | | free_air | Flexible cable in free air | FREE_AIR | Which methods each family offers: | Family | Methods offered | | -------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | 4D1, 4E1 | 1 · In conduit in a thermally insulated wall (A); 4 · In conduit on a wall (B); 20 · Clipped direct (C); 32 · Single-core on ladder or cleats (F) | | 4D2, 4E2 | 2 · Multicore in conduit in a thermally insulated wall (A); 4 · In conduit on a wall (B); 20 · Clipped direct (C); 23 · Multicore on perforated tray (E) | | 4D3, 4E3 | 20 · Clipped direct (C); 32 · Single-core on ladder or cleats (F) | | 4D4, 4E4 | 20 · Clipped direct (C); 23 · Multicore on perforated tray (E); 70 · In buried duct (D1); 72 · Buried direct (D2) | | 4D5 | 100 · T&E under insulation up to 100 mm; 101 · T&E under insulation over 100 mm; 102 · T&E touching inner wall; 103 · T&E not touching inner wall; 20 · Clipped direct (C); 1 · In conduit in a thermally insulated wall (A) | | 4F1, 4F2 | free_air · Flexible cable in free air | If the currently stored method is not valid for the selected family, the select shows a disabled placeholder option ("Choose a supported installation method") until you pick one from the list. ## Circuit arrangement A select whose options depend on the chosen cable and method (for example `2c`, `3ph`, or `dc`, depending on what the family/method combination supports). Changing the circuit arrangement also syncs the **Circuit type** field back in stage 01. ## Cable size (mm²) A select of the conductor cross-sectional areas available for the chosen family and method combination. Changing family or method resets the size to the first available option if the previously selected size is no longer offered. ## Resolved table capacity Below the size field, the panel shows a line in the form: > ‹ampacity table› + ‹voltage-drop table› · ‹N› A tabulated capacity identifying the two BS 7671 Appendix 4 source tables used (current-carrying capacity and voltage drop) for the resolved family/method/size/circuit combination, and the tabulated ampacity in amps before any correction factors are applied. ## Insulation operating temperature The conductor operating temperature used in the calculation is derived from the cable family, not entered separately: | Family | Operating temperature | | ----------------------------------- | --------------------- | | 4D1–4D5 (PVC) | 70 °C | | 4E1–4E4 (XLPE), 4F2 (thermosetting) | 90 °C | | 4F1 (thermosetting) | 60 °C | ## Related - [Correction factors](/tools/voltage-drop-cable-checker/docs/correction-factors) — how installation-condition corrections adjust the tabulated ampacity shown above. - [Manufacturer override](/tools/voltage-drop-cable-checker/docs/manufacturer-override) — the panel's "Manufacturer override" section, where you replace the tabulated voltage-drop coefficient with an R/X pair or a direct mV/A/m value. ## Previous - [Circuit and load inputs](/tools/voltage-drop-cable-checker/docs/circuit-and-load) — stage 01 fields.