Why Undersized Wiring is a Hazard

Using undersized wiring in an electrical circuit creates several serious dangers:

1. Overheating & Fire Risk – Wires have a rated ampacity, which is the maximum current they can safely carry. When a wire is too small for the load, it heats up excessively, potentially melting insulation and igniting nearby materials.

2. Voltage Drop – An undersized wire causes excessive voltage drop, meaning appliances and equipment don’t receive enough voltage to operate efficiently. This can lead to dim lights, motor failures, and premature equipment wear.

3. Breaker Nuisance Tripping – If the wire is too small, it will create more resistance, forcing the breaker to trip frequently. If someone installs a larger breaker to "fix" this (which is a code violation), it removes the overload protection, increasing fire risks.

4. Equipment Damage – Undersized wires can cause motors, compressors, and other sensitive electronics to overheat or work harder than they should, leading to premature failure.

5. Code Violation – The NEC (National Electrical Code) has strict requirements for wire sizing based on load, ambient temperature, and conduit fill. Using an undersized wire is a direct violation and could fail an inspection.