Torque Settings for Electrical Terminations
Recommended torque settings for MCBs, busbars, connectors, and cable terminations per manufacturer data
Why Torque Settings Matter
Loose connections are one of the leading causes of electrical fires. Correct torque ensures reliable, low-resistance joints that remain secure over time.
BS 7671 Regulation 526.2 requires that all connections are made in accordance with the manufacturer's instructions. Manufacturer torque values must be applied using a calibrated torque screwdriver. Under-tightening leads to high-resistance joints; over-tightening damages terminals and conductors.
Regulation 526.2
Consumer Unit Terminal Torque Values
Typical CU terminal torque by manufacturer
Manufacturer data sheets| Manufacturer | MCB (Nm) | RCBO (Nm) | Main Switch (Nm) | Busbar (Nm) |
|---|---|---|---|---|
| Hager | 2.0 | 2.0 | 3.5 | 4.0 |
| MK Sentry | 2.5 | 2.5 | 4.0 | 5.0 |
| Schneider | 2.0 | 2.0 | 3.5 | 4.5 |
| Wylex | 2.0 | 2.0 | 3.5 | 4.0 |
| Contactum | 2.0 | 2.0 | 3.5 | 4.5 |
Always verify against the specific product data sheet. Values may differ between ranges.
Accessory and General Termination Torque
General torque values for accessories and fixings
IET guidance and manufacturer data| Termination Type | Torque Range (Nm) | Notes |
|---|---|---|
| Socket outlet terminals | 0.8 - 1.2 | Plastic faceplate — do not overtighten |
| Light switch terminals | 0.5 - 0.8 | Small terminals, easily damaged |
| FCU / fused spur | 0.8 - 1.2 | Fuse carrier terminals may differ |
| Junction box | 0.5 - 1.0 | Depends on manufacturer |
| Cable gland (20mm) | 8 - 12 | Use a spanner, not a torque screwdriver |
| Earthing clamp | 2.0 - 3.0 | Main bonding connections |
| Cable lug bolt (M8) | 20 - 25 | Use a torque wrench |
Torque Screwdriver Selection
Most domestic and light commercial work requires a torque screwdriver covering 0.5 - 5.0 Nm. For distribution boards and busbars, a second tool covering 2.0 - 10.0 Nm may be needed. Cable glands and lugs require a torque wrench.
Calibration
Thermal Cycling