Can a 4mm Cable Go On a 32a Breaker?
2. The Definitive Answer (and Why It Matters)
Alright, let's cut to the chase: Generally, a 4mm cable is not suitable for a 32A breaker in most typical wiring installations. Now, that's a general statement. There are always exceptions, and local regulations and specific installation methods can influence the answer. But let's understand why that's the usual "no-go" answer.
The 4mm cable has a limited current-carrying capacity. It's designed to safely handle a certain amount of amperage before it starts to overheat. A 32A breaker, on the other hand, is designed to trip (turn off) when the current exceeds 32 amps. If you put a 4mm cable on a 32A breaker, the cable could potentially overheat before the breaker trips, creating a fire hazard. Its like putting a small bridge under a heavy load; it might hold for a while, but eventually, it will strain and possibly collapse.
The precise current-carrying capacity of a 4mm cable depends on factors like the type of cable (e.g., single-core, multi-core), the insulation material, the installation method (e.g., clipped direct, in conduit), and the ambient temperature. These factors can all affect how well the cable can dissipate heat. That's why simply saying "4mm cable = X amps" is an oversimplification.
Think of it like this: The breaker is designed to protect the cable, not the appliance. If you overload the circuit, the breaker should trip before the cable gets dangerously hot. If the cable's capacity is less than the breaker's rating, the breaker won't protect the cable properly. Therefore, use appropriately sized cable that the 32A breaker can safely works with!
