Exam 8: Feeder Installation and Load Calculation

A common example of a tap is for fixture whips that connect a ____ to a branch circuit.

To get accurate current readings where harmonics are involved, ammeters referred to as "____" must be used.

____ are multiples of a fundamental frequency.

What three circuit parameters must be known before feeder component selection can begin?

Branch-circuit conductors must have an ampacity not less than the ____ served.

When a smaller conductor is tapped from a larger conductor, the overcurrent protection at the beginning of the tap is ____ the ampacity of the smaller conductor.

To determine a reasonable minimum size for a neutral conductor, two types of loads must be considered-____.

If the ampacity of a feeder does not match a standard OCPD rating, then ____ be used.

Often the load is such that parallel conductors should be considered. This usually occurs with loads over ____ amperes.

Currents of the 3rd harmonic and odd multiples of the 3rd harmonic (9th, 15th, 21st, etc.)add together in the common neutral conductor of a 3-phase system, instead of canceling each other. These odd multiples are referred to as ____.

For installations where the nonlinear load is huge, most consulting engineers will specify ____-rated transformers.

In the United States, ____ Hz is standard or the fundamental frequency.

When sizing feeder conductors, ____ noncoincident loads (loads unlikely to be operated simultaneously such as the air-conditioning and the heating)need be included.

What are the three conditions of failure that may occur with a 3-phase, 4-wire wye system?

On a 3-phase, 4-wire, wye system, ____ reduction is allowed for nonlinear loads.

If a lighting load is considered to be continuous, as is the case in commercial buildings, a load factor of ____ percent must be applied.

What are the requirements for installing parallel conductors, as specified in NEC 310.10( G )?

Feeders are the part of the electrical system that connects the branch-circuit ____ to the electrical service equipment.

What wire and cable options do you have for combating excessive neutral current?

If the selected OCPD has a rating greater than 100-amperes, the conductors to be installed shall be selected from either the 75 degrees Celsius or ____ degrees Celsius column of NEC Table 310.16 .