What happens if you use the wrong size wire?

Using a wrong wire gauge leads to heat resistance, which can quickly turn into a fire hazard. Notably, each cable is designed to accommodate a specific amount of voltage ideal for a given application. If you use an inappropriately sized wire, it may end up melting due to the high amounts of flowing current.

Is it OK to use oversized wire?





There is nothing wrong with going with larger wire size, as long as that wire size doesn’t put you over on the conduit max fill rating. Wire sizing is basically based on heat dissipation based on how many amps will be going through the wire. Conduit max fill ratings are also based on that same heat dissipation.

Why must wire be sized properly?

The higher the amperage rating of the circuit, the larger the electrical wires need to be in order to avoid excess heat that can melt wires and cause fires.

Can you go down in wire size?

There is no such “step down” rule in the NEC. As long as the conductor is large enough for the load and is protected at or below its ampacity, there is no code issue.

What happens if my wire is too small?

The smaller wire loses more electricity to the heat loss than the larger capacity wire. For example, 100 feet of 12 gauge wire delivering 15 amps of current loses 77 watts of energy. A 10 gauge wire of the same length only loses 48 watts of energy when delivering the same load of current.

Can you mix 14 gauge and 12 gauge wire?





Anyway, the first subject is a bit touchy because it makes it difficult to perform an inspection when all of the wires coming into the panel are 12 but many of the circuits have 14 in them too. There is nothing against code mixing wire size for these circuits as long as the OCPD matches the smallest wire.

Does thicker wire conduct more electricity?

The thin wire will conduct electricity, but there is more electrical resistance. The thicker wire is like the four lane highway. There’s a lot less electrical resistance, and as a result, that light bulb burns brighter because more electricity can reach it.

Can you use thicker electrical wire?

Thicker is never worse than thinner electrically, but after some diameter the extra area gives you less and less return. This effect is proportional to frequency, so thicker cable is more useful for something like 60 Hz power as apposed to 10 kHz signal to a loudspeaker.

Is a bigger gauge wire better?

Also, the larger the cross-section, the greater the amount of current (amperage) the wire can safely carry before overheating. A wire with a smaller gauge (larger diameter) can carry more power than one with a larger gauge. In general, a lower AWG number is better than higher AWG.

Is it OK to mix 10 and 12 gauge wire?



You haven’t said how you will manage the transition from 10 gauge to 12 gauge. If you are thinking of wire nuts in a junction box, then the answer is that you cannot do this safely. The 20A breaker’s job is to protect the load wire connected to it. A 12 gauge wire needs a 20A breaker to protect it.

Can you connect two different size wires?

It must be noted that while it is possible to splice different types of Romex wire—12/2 to 12/3, for instance—you should never splice together wires of a different gauge. Wire gauge is determined by the amount of amperage the wire is expected to carry.

How do I choose a wire size?

There are two pieces to the wire size question: thickness (gauge) and length. To determine what gauge wire you need, consider the carrying capacity and the amount of current the wire needs to conduct (measured in amperage or amps). Wire gauge is directly related to how many amps you need to run through it.

Does wire size affect voltage?



Wire size is another important factor in determining voltage drop. Larger wire sizes (those with a greater diameter) will have less voltage drop than smaller wire sizes of the same length.

Can too small of wire cause voltage drop?

Next, a larger wire size (diameter) will have less voltage drop than a smaller size of the same length. Wire length is also a key factor. A shorter wire will have less voltage drop than a longer wire of the same diameter. Finally, the amount of current being carried will affect voltage drop levels.

How does wire thickness affect current?

The resistance of a thin wire is greater than the resistance of a thick wire because a thin wire has fewer electrons to carry the current.