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PDFWAC 296-307-36227

What access and working space must be provided for electrical equipment of 600 volts, nominal, or less?

Sufficient access and working space must be provided and maintained about all electric equipment to permit ready and safe operation and maintenance of such equipment.
(1) Unless otherwise indicated, the dimension of the working space in the direction of access to live parts operating at 600 volts or less and likely to require examination, adjustment, servicing, or maintenance while alive must be at least that indicated in the table below. Also, workspace must be at least 30 inches wide in front of the electric equipment. Distances must be measured from the live parts if they are exposed, or from the enclosure front or opening if the live parts are enclosed. Concrete, brick, or tile walls are considered grounded. Working space is not required behind assemblies such as dead-front switchboards or motor control centers where there are no renewable or adjustable parts such as fuses or switches on the back and where all connections are accessible from other directions.
Working Clearances
Nominal voltage
to ground
Minimum clear distance
for condition (ft)
(a)
(b)
(c)
0-150
13
13
3
151-600
13
3-1/2
4
Conditions:
(a) Exposed live parts on one side and no live or grounded parts on the other side of the working space, or exposed live parts on both sides guarded by suitable wood or other insulating material. Insulated wire or insulated busbars operating at 300 volts or less are not considered live parts.
 
(b) Exposed live parts on one side and grounded parts on the other side.
 
(c) Exposed live parts on both sides of the workspace (not guarded as in (a)) with the operator between.
(2) Working space required by this part must not be used for storage. When normally enclosed live parts are exposed for inspection or servicing, the working space, if in a passageway or general open space, must be suitably guarded.
(3) At least one entrance of sufficient area must be provided to give access to the working space about electric equipment.
(4) Where there are live parts normally exposed on the front of switchboards or motor control centers, the working space in front of such equipment must be at least 3 feet.
(5) All working spaces around service equipment, switchboards, panelboards, and motor control centers installed indoors must be adequately lit.
(6) The minimum headroom of working spaces about service equipment, switchboards, panelboards, or motor control centers must be 6 feet 3 inches.
"Motor control center" means an assembly of one or more enclosed sections having a common power bus and principally containing motor control units.
[WSR 97-09-013, recodified as § 296-307-36227, filed 4/7/97, effective 4/7/97. Statutory Authority: RCW 49.17.040, [49.17.]050 and [49.17.]060. WSR 96-22-048, § 296-306A-36227, filed 10/31/96, effective 12/1/96.]
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