In some older home electrical circuits, fuses were used in place of circuit breakers to protect equipment & wiring in the event of an electrical short. When an electrical short occurs, high current draw us typically the result.

In the case of the AC condenser, the motor windings can short to the case or to another "leg" of the motor. When this occurs, electrical current increases and voltage drops. The high current load creates a lot of heat and can result in melted wires or fires. If the wire melts, the situation kind of resolves itself as the current can no longer flow. But, if the circuit is not interrupted, the heat can create a fire and that is a serious concern.

So, we come back to the protection portion mentioned in the first paragraph. Electrical equipment must be protected against shorts in the form of a fuse (older) or a circuit breaker (modern). The fuse burns out opening the circuit or the circuit breaker "trips" and opens the circuit. Both of these methods open the circuit and stops the flow of current.

In this video, I looked in the AC condenser disconnect and the fuses had been replaced by copper pipe. This is very dangerous if there is not current protection in the main electrical panel. If the fuse is smaller than required by the condenser manufacturer, you can get nuisance trips where the start up current burns the fuse. Techs would put these pipes in to prevent the fuse from burning through. Very dangerous.

On the bright side here, there was the correct sized breaker in the panel protecting the condenser. The correct thing to have done in this case, was replace the fuse disconnect with a modern blade type disconnect.

#boxerinspections #residentialhomeinspection #electricalsafety

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