What Size Cable Do You Need for a 10 Amp Circuit?
For a 10 amp circuit, use 1.0mm² cable under BS 7671 Table 4D5A, rated at 14A clipped direct. Under NEC, 14 AWG handles 15A on a standard circuit. For conduit installations where derating applies, step up to 1.5mm² to maintain adequate current carrying capacity.
Quick Reference: Cable Size for 10 Amp Small Power Circuit by Standard
| Standard | Cable Size | Conditions | Reference |
|---|---|---|---|
| BS 7671 | 1.0mm² | Method C (clipped direct), PVC insulation | Table 4D5A |
| NEC | 14 AWG | 15A circuit, THWN-2, 75°C column | Table 310.16 |
| AS/NZS 3008 | 1.0mm² | Enclosed in conduit, max 30°C ambient | Table 13 |
| IEC 60364 | 1.0mm² | Reference method B, PVC insulation | Table B.52.4 |
Values shown are for copper conductors in typical domestic/commercial conditions. Actual size depends on installation method, ambient temperature, and cable length. Use our free cable sizing calculator for your exact scenario.
Typical Applications for a 10 Amp Small Power Circuit
- Small power circuit
- Bathroom shaver socket
- Towel rail circuit
- Outdoor lighting
Calculate Your Exact Cable Size
These are general guidelines. Your specific installation needs exact calculation accounting for cable route length, installation method, ambient temperature, and cable grouping.
Frequently Asked Questions
Is 1.0mm² enough for a 10 amp circuit?▼
Yes. 1.0mm² cable clipped direct (Method C) is rated at 14A under BS 7671 Table 4D5A, comfortably above 10A. In conduit (Method B), the rating drops to 12A — still sufficient but with less margin.
What is a 10 amp circuit used for?▼
10A circuits are common for dedicated small loads such as heated towel rails (80-150W), bathroom shaver sockets, outdoor lighting circuits, and low-power fixed appliances that do not justify a full 16A or 20A circuit.
Can I use a 10 amp MCB with 2.5mm² cable?▼
Yes, this is perfectly safe. The MCB protects the circuit at 10A, and 2.5mm² cable is rated well above this. The larger cable simply provides better voltage drop performance and future-proofing.
What is the maximum run length for 1.0mm² at 10 amps?▼
At 230V with a 5% voltage drop limit, 1.0mm² copper cable can run approximately 13m at 10A. For longer runs, use 1.5mm² (extends to about 22m) or 2.5mm² for runs beyond 30m.
Should I use 1.5mm² for a 10 amp circuit instead?▼
1.5mm² is a pragmatic choice for 10A circuits. It provides 20A capacity clipped direct, handles derating factors better, and costs only slightly more. Many electricians use 1.5mm² as a minimum for all fixed wiring.
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