Save
Busy. Please wait.
Log in with Clever
or
show password
Forgot Password?
Don't have an account?  Sign up 
Sign up using Clever
or
Username is available taken
show password


Make sure to remember your password. If you forget it there is no way for StudyStack to send you a reset link. You would need to create a new account. Your email address is only used to allow you to reset your password. See our Privacy Policy and Terms of Service.

Already a StudyStack user? Log In

Reset Password
Enter the associated with your account, and we'll email you a link to reset your password.
focusNode
Didn't know it?
click below
 
Knew it?
click below
Don't Know
Remaining cards (0)
Know
0:00
edit
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.

  Normal Size     Small Size show me how

Electrical Systems

Electrical Systems G8

TermDefinition
parallel circuits circuit that has two or more loads or branches that connected between the same two points
universal motor AC or DC electrical current used- handheld appliances, such as construction tools
Direct Current - DC The flow of electricity takes place at a constant time rate, voltage and in the same direction around the circuit. Often found in elevator work
Alternating Current - AC The flow of electricity reverses direction and changes voltage. It operates at 60 Hz.
Electric Current The flow of electrons through a conductor. Measured in amperes.
Gauge wire in construction 14 gauge copper wire - minimum Gauge - diameter of wire.
Electrical HVAC Simplest HVAC to install and operate. No space needed for pipes and duct work and temperature can be controlled with a separate thermostat in each room. Expensive..
ohm's law I Current= V Voltage/ R Resistance Current that will flow in a DC circuit is directly proportional to the voltage and inversely proportional to the resistance of the circuit
Ampere I Current amps = W power watts/ V Volts
Direct current low voltage lamps smaller filaments allow more precise control over light placement
Resistance Resistance is the reciprocal of conductance and is a measure of the insulating quality of a material. conductivity measures a material's ability to conduct heat. Resistance increases as the thickness of a material increases. R= 1/C
Transformer Device that changes the voltage in AC. Cannot be used in DC. Mounted on a concrete pad. Steps down voltage to 480V for building use. Transformer inside the building steps down to 120V for use at receptacles.
Generator Converts mechanical energy into electrical energy(electricity)
Panel boards A set of fuses or circuit breakers that is the central distribution point for electrical loading in the building
GFCI An outlet receptacle used in wet areas to provide additional protection against electrical shocks
Fuse Fusible link or wire with low melting point enclosed in a threaded porcelain cup or insulated fiber tube.
Circuit breakers Same function as a fuse, but mechanism is enclosed in a molded plastic case. Manually switched on and off to protect or open the circuit. Visually indicates a trip and can be reset
Conductance Number of BTUs that pass through one sq ft of material
Variable Voltage DC Used before 1990. Low efficiency, high maintenance, high thermal loss and high noise level
Variable Voltage, Variable-Frequency AC Elevator motor control- best system for high quality installation
AC Thyristor High power transistors to make accurate speed control of AC squirrel cage motors
DC Thyristor Greater rise and speed than AC version
Flexible Metal Conduit Excellent for transformers, motors, ballasts, where acoustic and vibration isolation in important. When covered in plastic jacket, useful in wet locations. Also knows as Flex or Greenfield
PVS Plastic Conduit Ideal for underground use
Electrical Equipment room location At the center of the facility, because it allows minimum lengths of thermal and electrical distribution runs.
Conductor cable Electrical panel to outlet = 10, 12, 14 AWG Appliance like range and dryer = 8, 10 AWG Smaller the AWG number- thicker the diameter. Thicker the wire- greater the current carrying capacity and longer the run distance
Conductors Wire/ cable/ busbars that carry electrical. They range in size from 16 GA to 4/0000.
cable Insulated 6 gauge or larger, or several smaller ones bound together in a single unit, referred to as cable
wire 8 gauge or smaller is called wire
busbars rectangular copper bars used to conduct high currents of electricity. power is transmitted through multiple bars, insulated from one another, and arranged in a metal housing called a busway
Critical distance Maximum length of drain pipe between a trap and an air vent. can be no more than 48 times the pipe diameter.
120/240 single phase residences and small office building.
277/480 three phase four wire large commercial buildings
2400/ 4160 three phase four wire industrial
120/208 three phase four wire small and medium commercial
Service entrance equipment transformers, service disconnect, fuses, meters, circuit breakers
Interior distribution equipment conductors, raceways, subpanels, submeters
loads power demand created by appliances and lights
Created by: rudolph.beukes
Popular Earth Science sets

 

 



Voices

Use these flashcards to help memorize information. Look at the large card and try to recall what is on the other side. Then click the card to flip it. If you knew the answer, click the green Know box. Otherwise, click the red Don't know box.

When you've placed seven or more cards in the Don't know box, click "retry" to try those cards again.

If you've accidentally put the card in the wrong box, just click on the card to take it out of the box.

You can also use your keyboard to move the cards as follows:

If you are logged in to your account, this website will remember which cards you know and don't know so that they are in the same box the next time you log in.

When you need a break, try one of the other activities listed below the flashcards like Matching, Snowman, or Hungry Bug. Although it may feel like you're playing a game, your brain is still making more connections with the information to help you out.

To see how well you know the information, try the Quiz or Test activity.

Pass complete!
"Know" box contains:
Time elapsed:
Retries:
restart all cards