Working space is very important for electrical worker safety and this section is all about providing enough working space for operation and maintenance of electrical equipment. Access to and egress from working space is the focus here. Access must be provided but it also must be maintained.
The equipment itself cannot be such that in the normal operation it impedes access to and egress from the working space. Open doors can, in some cases, impede access to and egress from the working space. This section requires that when the equipment doors are open it must not impede access to or egress from the working space. It also helps the user of NFPA 70 understand what is meant by impeding access or egress. The open doors must not restrict working space access to be less than 24 in. wide and 6.5 ft high.
This section is divided into 6 first level subdivisions as follows:
(A) Working Space
This first level subdivision includes the requirements for defining working space. The following 6 second level subdivisions help the user of NFPA 70 with working space.
(1) Depth of Working Space
(2) Width of Working Space
(3) Height of Working Space
(4) Limited Access
(5) Separation from High-Voltage Equipment
(6) Grade, Floor, or Working Platform
(B) Clear Spaces
Working space is only good when it is available. This section requires that the working space not be used for storage and it requires that when energized parts are exposed for inspection or servicing, the working space must be suitably guarded.
(C) Entrance to and Egress from Working Space
The electrical worker must be able to enter and egress from the working space. This section establishes a minimum requirement and then sets up the rules when the minimum requirement is not enough (i.e. large equipment). In addition to providing a number of egress and entrance means, this section establishes requirements for personnel doors. This first level subdivision is separated into three second level subdivisions as follows:
(1) Minimum Required
(2) Large Equipment
(3) Personnel Doors
(D) Illumination
Working space is important but so is proper illumination. This first level subdivision requires that illumination be provided for all working spaces about the following equipment
service equipment
switchboards
switchgear
enclosed panelboards
motor control centers installed indoors.
The requirement for illumination can be servd by adjacent light sources (See 210.70(A)(1), Exception No. 1) and all of the illumination for the working space cannot be controlled by an automatic means.
(E) Dedicated Equipment Space
The following equipment must be located in dedicated spaces and must be protected from damage:
Service equipment
Switchboards
Switchgear
Panelboards
Motor control centers
There is only one exception to this requirement regarding control equipment. When it must be adjacent to or within sight of its operating machinery as per NFPA 70, it is permitted to be located in those locations.
(F) Locked Electrical Equipment Rooms or Enclosures
Here are found the provisions recognizing that locked rooms or enclosures are considered accessible to qualified persons.
NFPA 70-2023 Changes
Minor changes were made in the informational note to align with the requirements of the 2020 NEC Style Manual. In addition, a new requirement pertaining to equipment doors now applies to all equipment. Previously found in the large equipment requirements, this new language requires the following:
“Open equipment doors shall not impede access to and egress from the working space. Access or egress is impeded if one or more simultaneously opened equipment doors restrict working space access to be less than 610 mm (24 in.) wide and 2.0 m (6 1⁄2 ft) high.”
A change was made in (C) to clarify that the appropriate reference is “enclosed panelboards” and not just “panelboards”. The panelboard definition does not include the enclosure. Various areas within the Code misuse this term and this change is probably one of many to come to address this issue throughout the Code.
(3) Height of Working Space
A change was made in Exception No. 2 to clarify that the appropriate reference is “enclosed panelboards” and not just “panelboards”. The panelboard definition does not include the enclosure. Various areas within the Code misuse this term and this change is probably one of many to come to address this issue throughout the Code
The changes here address a perceived inadequacy of existing language pertaining to not adequately addressing a condition where the workspace in front of a duct heater occurs above a partition. When this is the case, the submitter noted that it is impossible to work from a stepladder in front of the open enclosure. The electrician is allegedly forced into a difficult position to work from a ladder reducing safety for the electrical worker. Weight-bearing tee-bars are also an issue in that they cannot be set out of the way posing a similar issue. Low voltage work, available by special permission, is correlated in this text by the reference to 110.26(A)(1)(b). This approach was initially accepted for the 2017 NEC, but was subsequently lost after being relocated from CMP 17 in Art. 424 to CMP 1 in Art. 110. This wording also addresses the fact that headroom need not extend, and often does not extend, higher than that needed for the installation.
(6) Grade, Floor, or Working Platform
This is a new second level subdivision.
- The poor working conditions that were not properly covered in previous editions are now addressed in this requirement.
- The electrical equipment needs to be on a flat level working space for the workers to have a safe working condition.
- This will also assist enforcement to have a safe level surface while performing inspections.
(C) Entrance to and Egress from Working Space
Added text to clarify that the referenced 6 foot width of the equipment is the “combined width” of the electrical equipment. In addition, the reference to large equipment doors not impeding egress from or entrance to the working space is deleted as it is now required for all electrical equipment by this text being moved to 110.26(A).
(3) Personnel Doors
The references in Informational Notes are revised to conform with the designated structure in 3.1.3.1 and 4.1.3 of the 2020 NEC Style Manual. It was also clarified that equipment doors must open at least 90 degrees for working space for the electrical worker.
(D) Illumination
A change was made to clarify that the appropriate reference is “enclosed panelboards” and not just “panelboards”. The panelboard definition does not include the enclosure. Various areas within the Code misuse this term and this change is probably one of many to come to address this issue throughout the Code
(E) Dedicated Equipment Space
Added “service equipment” to the parent text of (E) to address such equipment as service disconnects required as part of 230.85 to ensure dedicated equipment space for these applications as well. Service equipment presents unique challenges to the electrical worker when trying to establish an electrically safe work condition. Incident energy at these locations is typically very high increasing risk.
In general, the changes made during this cycle may have the following impact:
- More space may be required for panelboards and other equipment to accommodate this change
- An Example of where this may have an impact could be where MCCs are encompassing presenting an aisle between the MCCS. Opening doors on both sides could present a violation.
- Note there are no exceptions for this requirement so supervised industrials would be impacted.
- Changes in (A)(6) can have significant impact where requirements for drainage or similar for sloping conflict.