One of the most common items on the inspectors red tag during the above ceiling electrical inspection is finding a disconnect switch mounted in a face down position. The NEC^® requires listed electrical equipment to be installed in accordance with the manufacturer’s instructions which are often found on the inside cover of a disconnect switch. Most disconnect switches will have specific language from the manufacturer, on the inside cover of the enclosure, prohibiting the switch from being installed in any position besides vertical.

Another common violation above the ceiling is having inadequate working space for a disconnect switch or VAV (variable air volume) box.

NEC 110.26(A)(4) provides the working space requirements for equipment with limited access that might need to be examined while energized. This includes disconnect switches for HVAC equipment in areas such as above a suspended ceiling.

Below is a preview of the NEC^® (NFPA 70). See the actual NEC^® text at NFPA.ORG for the complete code section. Once there, click on their link to free access to the edition of the NEC^® being enforced.

NEC 110.3(B) Installation and Use. Equipment that is listed, labeled, or both shall be installed and used in accordance with any instructions included in the listing or labeling.

NEC 110.26(A)(4) Limited Access. Where equipment operating at 1000 volts, nominal, or less to ground and likely to require examination, adjustment, servicing, or maintenance while energized is required by installation instructions or function to be located in a space with limited access, all of the following shall apply:

(a) Where equipment is installed above a lay-in ceiling, there shall be an opening not smaller than 559 mm × 559 mm (22 in. × 22 in.), or in a crawl space, there shall be an accessible opening not smaller than 559 mm × 762 mm (22 in. × 30 in.).

(b) The width of the working space shall be the width of the equipment enclosure or a minimum of 762 mm (30 in.), whichever is greater.

(c) All enclosure doors or hinged panels shall be capable of opening a minimum of 90 degrees.

(d) The space in front of the enclosure shall comply with the depth requirements of Table 110.26(A)(1). The maximum height of the working space shall be the height necessary to install the equipment in the limited space. A horizontal ceiling structural member or access panel shall be permitted in this space.