What Size Cable Do You Need for a Welding Machine?

For a workshop welding machine drawing 32-50A, use 10mm² cable on a dedicated 50A circuit under BS 7671. Under NEC Article 630, 6 AWG on a 50A circuit is standard per Table 310.16. Welders have an intermittent duty cycle (typically 20-60%), which may allow cable downsizing per NEC 630.11 — but a dedicated circuit with generous sizing is always recommended.

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Quick Reference: Cable Size for Welding Machine by Standard

Standard	Cable Size	Conditions	Reference
BS 7671	10mm²	50A dedicated circuit, intermittent duty	Table 4D1A
NEC	6 AWG	50A circuit, duty cycle considered, NEC 630	Table 310.16
AS/NZS 3008	10mm²	50A dedicated circuit	Table 13
IEC 60364	10mm²	50A circuit, duty cycle per IEC 60974	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 Welding Machine

MIG welder
TIG welder
Arc/stick welder
Plasma cutter

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These are general guidelines. Your specific installation needs exact calculation accounting for cable route length, installation method, ambient temperature, and cable grouping.

Cable Sizing Calculator Voltage Drop Calculator

Frequently Asked Questions

Can I run a welder from a 13A socket?▼

Only very small inverter welders rated under 2.5kW (10A). Most MIG and TIG welders draw 20-50A and require a dedicated circuit. Running a large welder from a 13A socket will trip the breaker or overheat the wiring.

What duty cycle means for cable sizing?▼

Welder duty cycle (e.g., 30% at 200A) means the welder operates for 30% of a 10-minute period. NEC Article 630.11 allows cable sizing based on the duty cycle — a 30% duty cycle welder can use cable rated at approximately 55% of the full nameplate current.

Does a welder need a dedicated circuit?▼

Yes. Welders draw high intermittent currents that cause voltage fluctuations. A dedicated circuit prevents these fluctuations from affecting other equipment and ensures the breaker is properly sized for the welder's characteristics.

What MCB type for a welder?▼

Use a Type C or Type D MCB for welding machines. The high inrush current when striking an arc can trip Type B MCBs. Type C handles 5-10x inrush, and Type D handles 10-20x, suitable for heavy-duty welders.

What size cable for a 200A MIG welder?▼

A 200A MIG welder typically has a 30% duty cycle and draws 32-45A from the supply at 230V. Use 10mm² on a 50A circuit. The 200A rating refers to welding output current, not supply current.

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What Size Cable Do You Need for a 40 Amp Circuit?6mm² (BS 7671)

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What Size Cable Do You Need for a 63 Amp Circuit?16mm² (BS 7671)

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What Size Cable Do You Need for a 32 Amp Circuit?4mm² (radial) or 2.5mm² (ring) (BS 7671)

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