76 ELECTRICALCONTRACTOR | MAR. 17 | WWW.ECMAG.COM
panelboard. A plumbing pipe has been
installed below the panelboard. There is
a violation of 110.26(E)( 1)(a) because the
plumbing pipe is located below the panelboard within the dedicated equipment
space. There is another violation of this
same section because the HVAC duct is
within the footprint of the panelboard
and not more than 6 feet above the top
of the panelboard (see Figure 3).
Depending on the condition, the
depth of working space as required by
110.26(A) shall be from 3 to 5 feet, but
the dedicated equipment space is only
the width and depth of the equipment.
For example, a panelboard has been
mounted on a concrete block wall. The
structural ceiling is 6 feet above the top
of the panelboard. There is nothing for-
eign to the electrical installation below
the panelboard. An HVAC duct is in the
same room as the panelboard, but it is not
directly over it. The depth of the panel-
board is almost 8 inches. The HVAC duct
is against the structural ceiling, but it is 8
inches away from the wall with the pan-
elboard mounted on it. While the HVAC
duct is close to the dedicated zone, it is not
within the dedicated zone. Therefore, this
installation is permitted (see Figure 4).
Sometimes, suspended ceilings are
located above panelboards or other
equipment requiring dedicated space.
In accordance with the exception to
110.26(E)( 1)(a), this would be permitted
under one condition. Suspended ceiling
with removable panels shall be permitted within the 6-foot zone. For example,
a panelboard is surface-mounted on a
wall in an office building. There is a suspended ceiling above the panelboard (see
Next month’s column continues the
discussion of requirements for electrical
MILLER, owner of Lighthouse Educational Services, teaches custom-tailored seminars
on the National Electrical Code and NFPA 70E. He is the author of “Illustrated Guide to
the National Electrical Code” and “Electrician’s Exam Prep Manual.” He can be reached at
615.333.3336 and Electric Writer@ymail.com. Connect with him on LinkedIn.
CODE IN FOCUS
FIGURE 4 EQUIPMENT’S
The dedicated zone is only the width and
depth of the equipment [110.26(E)( 1)(a)].
ceiling This HVAC duct is within
the dedicated space.
Side view of
FIGURE 5 SUSPENDED CEILINGS
Suspended ceilings with removable panels shall be permitted within the 6-foot dedicated equipment space [110.26(E)( 1)(a) Exception].
The suspended ceiling below is within the panelboard’s dedicated equipment space. This is permitted as long as the suspended ceiling
has removable panels.
Required dedicated equipment space
Panelboard in room below
the suspended ceiling