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Accessories have temperature ratings tooA 90 degree cable in a 70 degree box?
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Part of "correctly selected" is that the accessory matches the cable.
The mismatch to watch for
Plastic accessories — back boxes, surface boxes, switch fronts — are generally manufactured to 70 °C. Put a cable rated to 90 °C into one and the cable is fine. The accessory is not — it will still melt.
So above 70 °C, change the accessory. Metal, or a plastic rated higher. And where it is not obvious, consult the manufacturer's instructions — which is exactly what Guidance Note 3 p.21 asks you to take into account.
This is compatibility and strength — which takes you back to BS 7671 · Part 1 · Chapter 13, the fundamental principles.
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- Building Regs
- PAT
- Fundamental Inspection & Testing
- Initial Verification
- Periodic Inspection & Testing