OCPD
This part of a circuit breaker is used to open and close the switch.
What is "the handle".
Current in excess rated current for equipment, resulting in overload, short-circuit, or ground fault.
What is "overcurrent".
This current reaches high levels during motor start-up.
What is "inrush" current.
Feeder tap conductors are protected by short circuits by OCPD's located here.
What is the feeder OCPD.
Indirect connection from phase to ground or phase to phase.
What is "arcing fault current"
This part of a fuse melts during high levels of current.
What is the "link".
Motor nameplate current is used to select this value.
What is the motor overload trip value.
Feeder tap conductors are protected from overloads by the the OCPD's located here.
In the equipment containing the OCPD's that they terminate.
This characteristic of OCPD's causes them to operate faster with more current.
What is "inverse-time characteristic"
This UL section provides required interrupt ratings for class J fuses.
What is "UL 248".
This table is used to find the full-load current of 480v motors.
What is Table 430.250.
Fire pump circuits are generally not allowed to have this.
What is ground fault protection.
This instantaneous trip device offers only short circuit protection to a circuit.
What is a "motor circuit protector" or MCP.
This UL section details requirements for fuses used in DC Photovoltaic sources and output circuits.
What is UL 2579.
These code sections would apply to calculating the ampere rating of a dual element fuse for a multi-motor circuit.
430.52, 430.62, Tables 430.248-250.
When a utility transformer with an impedance of 5% is replaced by a unit with an impedance of 2.5%, the available fault current level will do this.
What is increase.
This part of a circuit breaker signals the contact mechanism to unlatch.
What is "the current sensing means or trip unit".
Circuit breakers should be inspected and tested when they interrupt a fault at this level.
What is "near their interrupt rating".
This is the golden rule for code tests.
What is "RTFQ"?
When required, services will be labeled with the available fault current, and the date this was performed.
What is fault current calculation.