The size and type of job will dictate how many rough inspections are likely to take place. For a commercial job such as a new school or shopping mall, the inspector will be called for rough inspections of electrical in walls many times as the electrician completes work in each area of the building. For a single-family dwelling, the electrical inspector will want to come out once to perform the rough inspection after all electrical wiring methods have been installed in floors, walls, and ceilings.
When an inspector approves rough electrical in a wall, the inspector is assuming that after the inspection is over, the wall will be closed up immediately with no additional electrical work needing to be done in that wall. Never modify or add more electrical in a wall the inspector approved after the inspector leaves unless another inspection occurs.
Before requesting a rough inspection of the electrical installation in walls or other areas that will be concealed, be sure to have the below items ready. The below list is general and does not address every possible type of installation:
- Have the inspector come out after the electrical work is done but before any insulation or sheetrock is installed
- Install and properly support all electrical boxes
- Ground all metal boxes. Unless the inspector plans to open boxes and remove devices at the final inspection, this rough inspection is the only time the grounding of the boxes can easily be seen. Some inspectors will be ok with only a grounding pigtail connected to the metal box at the rough inspection if wiring has not yet been pulled to each box or enclosure
- Make sure all knockouts or unused openings in boxes are sealed
- Install all mud rings
- Install, secure, and support all electrical conduits and cables according to the applicable NEC® Article depending on which type of raceways or cables are used
- If the wiring methods are cables, now is the time to pay close attention to box fill to comply with NEC® 314.16. If conduit is installed between boxes, then it is likely that the conductors will be pulled into the boxes later after the walls are closed up
- Install any needed nail plates or other protection to protect cables from nails or screws that will be used to install the wall finish materials
- Install any recessed panelboard cabinets and terminate all cables or conduits to the cabinets
- Install all recessed lighting and exhaust fans
- Install the grounding electrode conductor to join the grounding electrode to the service equipment
- Install any required water bond to the interior metallic water piping
- Install any required gas pipe bond to the interior metallic gas piping