UFC 3-520-01
June 10, 2002
Glossary-8
Closed Transition Switch--Transfer switch that provides a momentary paralleling of
both power sources during a transfer in either direction. The closed transition is
possible only when the sources are properly interfaced and synchronized.
Constant Voltage Transformer--A ferroresonant transformer used for voltage
regulation in single-phase circuits.
Current Limiting Circuit Breaker--A circuit breaker that does not utilize a fusible
element, and that when operati ng within its predetermined current-limiting range, limits
the let-through I
2
t to a value less than the I
2
t of one-half cycle of the expected
symmetrical current.
Current Limiting Fused Circuit Breaker--A circuit breaker in combination with
integral current-limiting fuses that, when it interrupts a current within its specified current
limiting range, purposely introduces an impedance so as to reduce the current
magnitude and duration.
DC Link--The direct-current power interconnection between rectifier or rectifier/charger
and inverter function units.
Delayed Transition--A timed disconnection of the load from the power sources during
transfer, primarily to allow for the decay of motor residual voltage.
Earth Ground--An electrical connection to earth obtained by a grounding electrode
system.
Electromagnetic Relay--An electromechanical relay that operates principally by action
of an electromagnetic element that is energized by the input quantity.
Electromechanical Relay--A relay that operates by physical movement of parts
resulting from electromagnetic, electrostatic, or electrothermic forces created by the
input quantities.
Emergency Lighting System--A system capable of providing minimum required
illumination specified in NFPA 101, Code for Safety to Life from Fire in Buildings and
Structures, Section 5.9. It includes the lighting units, related backup power source(s),
and required connections.
Equipment Grounding Conductor--The conductor used to connect the noncurrent
carrying parts of conduits, raceways, and equipment enclosures to the grounded
conductor (neutral) and the grounding electrode at the service equipment (main panel)
or secondary of a separately derived system, such as an isolation transformer.
Existing Facility--A facility is existing if changes to be made are cosmetic or minor in
nature.
Summary :
Current Limiting Circuit Breaker--A circuit breaker that does not utilize a fusible element, and that when operati ng within its predetermined current-limiting range, limits the let-through I 2 t to a value less than the I 2 t of one-half cycle of the expected symmetrical current. Current Limiting Fused Circuit Breaker--A circuit breaker in combination with integral current-limiting fuses that, when it interrupts a current within its specified current limiting range, purposely introduces an impedance so as to reduce the current magnitude and duration.
Tags :
current,sources,circuit,power,oltage,system,electromagnetic,limiting,grounding,equipment,used,earth,parts