Use this chart to pick the right cable size for a borehole, submersible or booster pump. Find your motor size (kW or HP) in the left column, then read across: each figure is the maximum cable length in metres for that cable size (mm²) before voltage drop becomes a problem. If your cable run is longer than the figure shown, move up to the next cable size.
230V single-phase pump cable sizing chart
| Motor HP | Motor kW | 1.5 mm² | 2.5 mm² | 4 mm² | 6 mm² | 10 mm² | 16 mm² | 25 mm² | 35 mm² | 50 mm² |
|---|---|---|---|---|---|---|---|---|---|---|
| 0.33 | 0.25 | 170 | 280 | 450 | 670 | 1130 | 1750 | 2640 | 3590 | 4940 |
| 0.5 | 0.37 | 120 | 200 | 320 | 480 | 810 | 1260 | 1900 | 2590 | 3580 |
| 0.75 | 0.55 | 80 | 130 | 220 | 320 | 550 | 850 | 1290 | 1760 | 2430 |
| 1 | 0.75 | 60 | 100 | 170 | 250 | 430 | 670 | 1010 | 1380 | 1910 |
| 1.5 | 1.1 | 40 | 70 | 120 | 180 | 300 | 470 | 710 | 960 | 1360 |
| 2 | 1.5 | 30 | 60 | 90 | 130 | 230 | 360 | 550 | 760 | 1060 |
| 3 | 2.2 | 20 | 40 | 60 | 90 | 150 | 230 | 350 | 490 | 680 |
380V three-phase pump cable sizing chart
| Motor HP | Motor kW | 1.5 mm² | 2.5 mm² | 4 mm² | 6 mm² | 10 mm² | 16 mm² | 25 mm² | 35 mm² | 50 mm² |
|---|---|---|---|---|---|---|---|---|---|---|
| 0.5 | 0.37 | 810 | 1350 | 2160 | 3240 | 5500 | 8530 | – | – | – |
| 0.75 | 0.55 | 550 | 920 | 1480 | 2230 | 3780 | 5860 | 8890 | – | – |
| 1 | 0.75 | 410 | 680 | 1090 | 1640 | 2780 | 4330 | 6570 | 9010 | – |
| 1.5 | 1.1 | 300 | 500 | 810 | 1210 | 2060 | 3200 | 4850 | 6640 | 9220 |
| 2 | 1.5 | 220 | 370 | 590 | 880 | 1500 | 2340 | 3560 | 4890 | 6380 |
| 3 | 2.2 | 150 | 250 | 400 | 600 | 1030 | 1600 | 2440 | 3350 | 4680 |
| 5 | 3.7 | 90 | 150 | 240 | 370 | 630 | 980 | 1490 | 2050 | 2870 |
| 7.5 | 5.5 | 60 | 110 | 170 | 260 | 440 | 690 | 1060 | 1450 | 2030 |
| 10 | 7.5 | 50 | 80 | 130 | 200 | 340 | 530 | 810 | 1110 | 1560 |
| 15 | 11 | – | 50 | 90 | 130 | 230 | 360 | 550 | 750 | 1060 |
| 20 | 15 | – | – | 70 | 100 | 170 | 270 | 410 | 570 | 800 |
| 25 | 18.5 | – | – | – | 80 | 140 | 210 | 330 | 450 | 630 |
| 30 | 22 | – | – | – | 70 | 120 | 180 | 280 | 380 | 540 |
| 40 | 30 | – | – | – | – | 90 | 130 | 210 | 280 | 400 |
| 50 | 37 | – | – | – | – | – | 110 | 170 | 230 | 320 |
A dash (–) means that combination isn’t listed – the cable is either too small for the motor or bigger than you would ever need. Figures are a guide only; always check against the pump manufacturer’s installation manual and SANS 10142 wiring rules. Not sure which cable or pump you need? Ask us or WhatsApp 061 744 1001.
Need an electrician to install the cable?
Cable size is only part of a safe pump installation. The pump also needs its own circuit breaker in the DB board, earth leakage protection, a weatherproof isolator and the correct starter or control box. In Pretoria and Centurion, Electrician Worx can wire borehole, booster and pool pump circuits and check that your cable run matches the motor size before you switch on.
Prefer a picture? Here is the same chart as an image you can save or print.
