In terms of quantity, how many equipment grounding conductors can enter a box without requiring additional volume allowance?

The correct answer is based on the requirements set forth in the National Electrical Code (NEC). According to NEC Article 314, the volume allowance for conductors entering a box includes specific provisions for equipment grounding conductors.

When considering grounding conductors, the NEC states that one equipment grounding conductor does not require additional volume. However, for multiple grounding conductors, it specifies that up to three conductors can enter a box without necessitating an increase in volume for each additional conductor.

When four or more grounding conductors are present, the box volume must be increased to accommodate this additional wiring. This means that if only one grounding conductor is entering, it is covered under the standard volume of the box, and for up to three, no additional volume needs to be allocated. Once the fourth grounding conductor is added, it triggers the rule for increased volume.

Therefore, the provision allows for three equipment grounding conductors to enter a box without necessitating additional volume, leading to the interpretation of the answer as four being the key limit before added volume is required.