Electrical System Design for Biosystems Structures

A collection of flashcards based on the lecture notes for the Electrical System Design course, covering key concepts related to electrical conductors, ampacity, insulation types, voltage drop, and more.

What does AWG stand for in electrical wiring?

American Wire Gauge, used to identify specific wire diameters.

Define stranded wire.

A type of wire that consists of a group of wires twisted together to form a metallic string.

What is ampacity?

The current-carrying capacity of wires and cables, depending on gauge, metal composition, and thermal properties of insulation.

What is the purpose of junction and pull boxes?

They provide access points for pulling and feeding conductors into a raceway system.

How is a mil defined?

A mil is equal to 1/1000 inch and is used to measure round wire diameter.

What is the formula for calculating the circular mil?

Circular mil = d², where d is the diameter in mils.

What must be considered when selecting conductors for electrical systems?

1. Ampacity must be greater than current drawn by loads. 2. Voltage drop must be within operating range of loads.

What is the recommended ampacity of a conductor relative to current?

A conductor's ampacity should be at least 120% of the current drawn.

What is the maximum allowed voltage drop in a branch circuit?

Limited to 3% of the system’s voltage from the panel board to the farthest outlet.

What factors should be considered when calculating voltage drop?

Ohm’s Law and the Voltage Drop Formula, which takes into account the resistance of the conductor and other parameters.

What are the two classification types of insulation?

1. Thermoplastic - softens when heated and becomes rigid when cooled. 2. Thermoset - cures when heated and does not soften again.

What information is provided by wire markings from the manufacturer?

Gauge, maximum voltage rating, insulation code, maximum temperature code, and any present sheath abbreviation.

What is Ohm's Law used for in electrical engineering?

To calculate voltage drop in a conductor.

What is the resistance of AWG 12 wire in terms of ohms per 1000 feet?

The resistance is 1.98Ω/1000ft.

What happens if the conductor exceeds its ampacity?

Excessive heating may occur, leading to insulation melting or damaging the conductor.