WORKING SPACE FOR ELECTRICAL EQUIPMENTS / PANELS (PART-2)

(D) Illumination:

• Service equipment, switchboards, panel boards, as well as motor control centers located in indoors must have illumination and controlled by automatic means only.

(E) Dedicated Equipment Space:

• Switchboards, panel boards, and motor control centres must have dedicated equipment space as follows:

(1) Indoors (110.26 (E))

(a) Dedicated Electrical Space:

• a dedicated electrical space is defined as the space equal to the width and the depth of the equipment extending from the floor to a height of 1.8 m above the equipment or the structural ceiling, whichever is lower.
• No piping, ducts, or other foreign equipment can be installed in this dedicated Electrical footprint space.
• Busways, conduits, raceways, and cables are permitted to enter through this Dedicated Electrical Space / zone.

(b) Foreign Systems:

• Foreign systems can be located above the ded­icated space if proper protection is installed to prevent damage to the elec­trical equipment from condensation, leaks, or breaks in the foreign systems,
• This can be achieved by installation of simple as a drip-pan.

(c) Sprinkler Protection (110.26(E)):

• Sprinkler protection shall be permitted in the area above the dedicated electrical space if the electrical equipment is properly protected against Water leaks or breaks in the Sprinkler system.

• Sprinkler System shall not be permitted in Working Space of Electrical Equipment.
• Hence the sprinkler piping can run above the dedicated electrical space 1.8 m above equipment as long as the Electrical equipment below is protected from leaks, condensation, and even breaks by using dedicated Drip Pan.
• But drip pans which may create an obstruction to sprinkler system discharge. So, it is always advisable to avoid locating sprinklers and sprinkler piping directly above electrical equipment and sprinklers and sprinkler piping are not permitted to be located directly within the working space for the equipment as shown in the figure. 

• Where all of the following conditions are met, sprinklers shall not be required in electrical rooms
• (1) The room is dedicated to electrical equipment only.
• (2) Only dry-type or liquid-type with listed K-class fluid electrical equipment is used.
• (3) Equipment is installed in a 2-hour fire-rated enclosure including protection for penetrations.
• (4) Storage is not permitted in the room.

(d) Suspended Ceilings:

• A dropped, Suspended or other similar hanging ceiling that does not add strength to the building structure is permitted to be located directly in the dedicated space, because they are not considered structural ceilings. Building structural members are also permitted in this space.

(2) OUTDOOR:

• Outdoor Electrical installations must comply with the following:

(a) Installation Requirements:

• Switchboards, switchgear, panel boards installed outdoors must be Installed in identified enclosures
• Protected from accidental contact by unauthorized personnel, or by vehicular traffic.
• Protected by accidental spillage or leakage from piping systems

(b) Work Space.

• The working clearance space shall include the zone described in 110.26(A). No architectural appurtenance or other equipment shall be located in this zone.
• Exception: Structural overhangs or roof extensions shall be permitted in this zone.

(c) Dedicated Equipment Space Outdoor.

• The footprint space (width and depth of the equipment) extending from grade to a height of 6 ft above the equipment must be dedicated for the electrical installation.
• No piping, ducts, or other equipment foreign to the electrical installation can be installed in this dedicated footprint space.

(F) Locked Electrical Equipment Rooms or Enclosures.

• Electrical equipment rooms and enclosures housing electrical equipment can be controlled by locks because they are still considered to be accessi­ble to qualified persons who require access.

Enclosure for Electrical Installations (110.31)

• Electrical installations in an Electrical Room, or closed area surrounded by a wall, screen, or fence shall be access or controlled by a lock(s) or other approved manners.
• Electrical Installation Area (Indoor and Outdoor) shall be accessible to qualified persons only.
• The type of enclosure used shall be designed and constructed according to the nature and degree of the hazard(s) associated with the installation.
• For Outdoor Type Electrical installations shall be covered by Fence.

(a) Fence:

• A fence shall not be less than 2.1 m (7 ft) in height or a combination of 1.8 m (6 ft) or more of fence fabric and a 300 mm (1 ft) or more extension utilizing three or more strands of barbed wire or equivalent.
• The distance from the fence to live parts shall be not less than given in Table 110.31.

(A) Electrical Room.

• Where an electrical vault is required or specified for conductors and equipment 110.31(A)(1) to (A)(5) shall apply.
• (1) Walls and Roof. The walls and roof shall be constructed of a minimum fire rating of 3 hours. For the purpose of this section, studs and wallboard construction shall not be permitted.
• (2) Floors. The floors of vaults in contact with the earth shall be of concrete that is not less than 102 mm (4 in.) thick, but where the vault is constructed with a vacant space or other stories below it, the floor shall have adequate structural strength for the load imposed on it and a minimum fire resistance of 3 hours.
• (3) Doors. Each doorway leading into a vault from the building interior shall be provided with a tight-fitting door that has a minimum fire rating of 3 hours.
• (4) Locks. Doors shall be equipped with locks, and doors shall be kept locked, with access allowed only to qualified persons. Personnel doors shall swing out and be equipped with panic bars, pressure plates, or other devices that are normally latched but that open under simple pressure.

 (B) Enclosed Equipment Accessible to Unqualified Persons.

• Ventilating or similar openings in equipment shall be designed such that foreign objects inserted through these openings are deflected from energized parts.
• Where exposed to physical damage from vehicular traffic, suitable guards shall be provided.
• Non-metallic or metal-enclosed equipment located outdoors and accessible to the general public shall be designed such that exposed nuts or bolts cannot be readily removed, permitting access to live parts.
• Where non-metallic or metal-enclosed equipment is accessible to the general public and the bottom of the enclosure is less than 2.5 m (8 ft) above the floor or grade level, the enclosure door or hinged cover shall be kept locked.
• Doors and covers of enclosures used solely as pull boxes, splice boxes, or junction boxes shall be locked, bolted, or screwed on.
• Underground box covers that weigh over 45.4 kg (100 lb) shall be considered as meeting this requirement.