COSC 325 Houston (electrical)

Set screw connector

box fitting that relies on pressure of a screw against conduit to hold it in place

Electrical Connections

Soldering: 60% tin, 40% lead, amount of tin determines strength

Tape: insulates up to 600 V

Wire nuts: hold wires together and has color codes to indicate conductors

Splice: twist

Grounding

Provides a harmless, low-resistance path for electricity to follow.

Single phase power

permits the potential difference to drop to zero with every change in the direction of current flow

circuit

the complete path that an electric current travels along

Three phase power

a combination of 3 alternating voltage wave forms, each displaced 120 electrical degrees (1/3 of a cycle) apart

Transformer

A device that increases or decreases the voltage of alternating current

Current

the flow of electrons

Generated Electricity

Alternating current (AC) created by power plant generators. Power plants create 3 phase AC

A junction box

Box used to join several electrical wires into a circuit

NM cable

"romex" Non-metallic sheathed cable

knockout

Round indentation punched into the metal of a box and held in place by un punched narrow strips of metal

GFCI receptacle

When an existing two-wire, nongrounding-type receptacle is replaced in a location where the CODE requires a GFCI receptacle, it is permitted to be replaced by a ...

RMC Conduit

Rigid metal conduit, heavy duty. Threaded connections

EMT Conduit

Electrical metal tubing, very thin walls

FMC Conduit

Flexible metal conduit, wire is not added until installation is complete

Insulator materials

Rubber, plastic, air, glass, paper

Compression connector

Box fitting that firmly secures conduit to a box by utilizing a nut that compresses a ring into conduit

Conductor materials

a material that easily allows the flow of electricity- metals

Power formula

E=P/I (Voltage=Power/Current)

Circuit Breaker

Overcurrent protection device with a mechanical mechanism that manually or automatically opens a circuit when overload or short circuit occurs

3 Phase "high"

480/277V, 3 hot wires, 480="line to line", 277="line to neutral"

3 Phases "Low"

208/120V, 3 hot wires

LOTO

Lock Out Tag Out

Electrical Energy Calculations (kWh)

E=PxT

Service Panel

The main distribution box that receives the electricity and distributes it to various points in the house through branch circuits

Amp

A unit of electric strength

Lumens

a measurement of the brightness of light

Where is 120/240V, single phase, 3 wire used?

Residential, interior lighting wiring

What is 120/208V 3 phase 4 wire used for?

Providing large amounts of low voltage power

Foot Candles; Lux

Lumens divided by area

How many "hot" wires in single phase power?

2

incadescent light

a filament lamp rendered luminous by electric current; white light

Fluorescent

Low pressure discharge, ionization of mercury vapor

Compact Fluorescent Lamp (CFL)

lamp made with one or more small, folded fluorescent tubes and equipped with a screw base. The ballast is a separate control gear or is built into the unit as an integral part of the system

Three-way switches

Are used where it is desired to control lamps from two different points, as in a stairwell.

Four way switch

switch used in conjunction with the 3 Way switches to control lights from the three locations

Automatic Transfer Switch (ATS)

A device that is basically a double throw switch of generally 3-pole connection that will automatically transfer the power from the standby generator to the building circuitry during electrical power failure.

Generator

A machine that converts mechanical energy into electrical energy

Manually controlled circuit

Requires a person to initiate

MC cable

Metal Clad Cable

NEMA 1

Used for indoor use to provide protection

NEMA 3R

Used for outdoor protection

What do you do if you see a XMFR opened up?

CALL UTILITY COMPANY IMMEDIATELY

How many feet clearance is needed for any kind of electrical gear?

3 feet

How tall can the tallest breaker or switch be?

6'7"

MCB

(M.ain C.ircuit B.reaker)

Will cut off all electrical power.

MLO

Main Lug Only, meaning no breaker switch

sign for switch

$

What division is electrical

26

What plans show how panels fed and size of feeders

Riser plans

What shows how power gets to building

Site plan

NEC

Governs electrical installation on most projects

AWG (American Wire Gauge)

A standard rating that indicates the diameter of a wire, such as the conducting core of a coaxial cable.

Lowest LEED certification level

Certified

Which is bigger, 12 AWG or 4/0?

4/0