What could happen if conduit fill exceeds 40%?

When conduit fill exceeds 40%, it can lead to potential overheating of the wires within the conduit. This is because excessive fill restricts airflow around the conductors, which is necessary for dissipating heat generated during operation. As current flows through the wires, they produce heat, and if there isn't sufficient space for air circulation, temperatures can rise above safe levels. Overheating can damage the insulation on the wires and may lead to failures or even fire hazards.

In comparison, the other options do not align with the implications of exceeding conduit fill limits. Increased electrical efficiency, improved durability of the conduit, and reduced installation time are not direct results of exceeding the recommended fill percentage. Instead, they misrepresent the risks associated with insufficient space for the proper functioning of electrical installations.