E2 Plan Review and Inspections 3

Question 1

During a plan review, an inspector sees that the one-line diagram shows a 2000A service with a single 2000A disconnect. The building also has an emergency generator. Which NEC section governs the number and grouping of service disconnects?

Accepted Answer

NEC 230.71, which limits service disconnecting means to a maximum of six disconnects

Answer

NEC 230.71 permits a maximum of six disconnects for a service, and all disconnects must be grouped together.

Question 2

An inspector is reviewing plans for a restaurant kitchen and notices that the equipment grounding conductors for all circuits are shown as the same size. What potential issue should be investigated?

Accepted Answer

NEC 250.122 requires EGCs to be sized based on the rating of the overcurrent device protecting each circuit

Answer

NEC 250.122 requires equipment grounding conductors to be sized based on the ampere rating of the overcurrent protective device in the circuit, so larger circuits need larger EGCs.

Question 3

A commercial plan review shows a 208Y/120V panelboard feeding a dedicated computer room. The plans indicate that isolated ground receptacles will be installed. What must the inspector verify on the plans?

Accepted Answer

That the isolated ground circuit includes an insulated equipment grounding conductor run back to the panel, and the panel enclosure is still grounded

Answer

NEC 250.146(D) requires isolated ground receptacles to include an insulated EGC back to the source, while the panel enclosure must remain grounded.

Question 4

While reviewing commercial plans, an inspector finds that a rooftop HVAC unit disconnect is shown mounted on the rooftop adjacent to the unit. The unit is fed by a 460V feeder. Which requirement is most critical to verify?

Accepted Answer

That the disconnect is located within sight of the unit and is readily accessible per NEC 430.102

Answer

NEC 430.102(B) requires a disconnect within sight of motor-driven equipment, and NEC 430.107 requires it to be readily accessible.

Question 5

During a rough-in inspection of a commercial building, the inspector observes that flexible conduit (FMC) is used for the final connection to a rooftop air handler. The run is 10 feet long. What NEC requirement applies?

Accepted Answer

FMC over 6 feet requires a bonding jumper per NEC 250.118 since it may not provide an adequate ground path

Answer

FMC longer than 6 feet may not provide an adequate ground path, so NEC 250.118 requires a bonding jumper in parallel with FMC exceeding this limit.

(E2) E2 Commercial Electrical Inspector Practice Test

(E2) E2 Commercial Electrical Inspector Practice Test

E2 Plan Review and Inspections 3