Terms/Definitions
Any current in excess of the rated current of equipment or the ampacity of a conductor
What is an overcurrent?
The circuit conductors between the final overcurrent device protecting the circuit and the outlet(s)
What is a branch circuit?
Often available in class J, H, and RK1
What is a fuse?
This is the smallest standard size fuse.
What is a 1A fuse?
OCPD shall be provided in each ungrounded circuit conductor and shall be located here.
What is at the point where conductors receive their supply?
240.21
An electrical circuit condition best described as a phase or ungrounded conductor that comes into contact with another phase conductor or grounded conductor
What is short circuit?
Overcurrent protection shall be provided in this type of circuit conductor
What is ungrounded?
Encased in a sealed insulating case with a center mounted toggle operating handle
What is molded case circuit breaker?
Interrupting ratings other than 10,000 must be marked on this type of OCPD
What is a fuse?
Maximum size OCPD allowed to protect a #10AWG THHN.
What is 30 amps?
240.4(D)
A current greater than the equipment rated current or conductor ampacity, which is confined to the normal conductive paths provided by the conductors and other equipment
What is an overload?
Supplemental overcurrent protection devices are usually installed by who?
Who is the manufacturer?
Fuses often come in two different AC voltage ratings, 250VAC and this.
What is 600V?
The highest current at rated voltage that a device is identified to interrupt under standard test conditions
What is interrupting rating?
Switches must have an rating indicating it is capable of safely interrupting what?
What is load current?
The amount of current available for a short circuit condition in which there is a direct connection between the ungrounded conduductors of a circuit.
What is bolted fault current?
In some breakers, as the current gets larger the opening time gets quicker, often referred to as this.
What is an inverse time circuit breaker ?
What is low voltage power circuit breaker?
Typically, the single most influencing factor on the magnitude of the available short-circuit current at the service
What is the service transformer?
Tap conductors that are run 20' in length are going to need to have an ampacity based on both: the rating of what the tap is terminated in, and also this.
What is 1/3 of the rating of OCPD protecting the feeder?
A graph that plots the interrupting time of an overcurrent device based on a given amount of current
What is a time current curve?
A category of overcurrent protection used for services, feeders, branch circuits, and equipment providing a full range of protection against short circuits, ground faults, and overloads.
What is branch circuit overcurrent protection?
Or
What is branch circuit?
An OCPD with a molded plastic frame, often installed in switchboards and requires a ratcheting device to close the circuit, but you cannot service any of the components.
What is an ICCB?
This type of circuit breaker such as 120/240V or 277/480V, is permitted on a solidly grounded system where the nominal voltage of any one conductor to ground doesn’t exceed the lower of the two values, and the nominal voltage between any two conductors doesn’t exceed the higher value.
What is slash rated?
According to 215.4, you must be able to serve THIS load when you are sizing your conductors, after you adjust and correct.
What is the maximum load to be served?