Exam 12: Panelboard Selection and Installation
For electrical equipment not considered large, at least ____ entrance(s)of sufficient area is required to provide access to and egress from the working space.
A
What are the requirements for panelboard cabinet sizing?
If there are special requirements for using the wiring gutters in a panelboard, the physical size of the cabinet is required to be sufficient to accommodate those requirements. Often a feeder serves two or more panelboards, in which case either a junction box or wireway is installed or the feeder connects to the first panelboard and then is extended to the others. In some cases, double lugs are installed for the phase conductors and neutral, if used. Other designs have feed-through lugs with the supply-side feeder conductors connected to the line terminals of the first panelboard and conductors of the same size connected from the load terminals of the first panelboard to the line terminals of the second panelboard. Both methods require the installation of additional feeder conductors. The cabinet must have sufficient gutter width for bending these conductors and for the required splices if splices are made.
All working spaces must allow for the opening of equipment doors and hinged panels to at least a ____ degree position.
C
The circuit directory gives the ____ for each circuit in a wording that would be clear for "nonelectrical" people to decipher and identify the circuit number for luminaires, receptacles, appliances, or equipment.
Often a feeder serves two or more panelboards, in which case either a(n)____ or wireway is installed or the feeder connects to the first panelboard and then is extended to the others.
If more than one system voltage is used for premises wiring, how should panelboards be marked?
What is the difference between past and current usages of the term panelboard?
The reasoning for identifying the system voltage(s)and phases is ____.
Unused openings in panelboards and switches should be ____.
Working space height is required to not be less than ____ ft.
What are the three conditions related to live parts and working space?
Panelboard ratings are determined by the ____ capacity of the internal main bus.
NEC 408.36(A)stipulates that if the panelboard contains snap switches with a rating of ____ amperes or less, the panelboard overcurrent protection is not permitted to exceed 200 amperes.
Conductors for 480Y/277-volt systems are generally brown, orange, ____ for the ungrounded conductors and gray for the grounded conductor..
The feeder overcurrent protection is sized for the ____ of the feeder conductor.
Separate feeders are to be run from the main service equipment to each of the areas of the commercial building. Each feeder will terminate in a ____, which generally will be installed in the area to be served.
For system voltages of 0 to 150 volts to ground, the minimum depth of working space is ____ ft under all three working space conditions.
Most large commercial buildings use two voltages: 480Y/277 volts and ____/120 volts.
In general, panelboards are constructed so the ____ run vertically for nearly the height of the panelboard.
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