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harlanjr
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what are the 2 types of cut outs
load break; non load break
CSP transformer
completely self protected
what is typically attached to the tank of a CSP transformer
surge arrestor
what two protective devices are built into CPS transformers
an internal current limiting fuse; secondary circuit breaker
in a CPS transformer what does the handle operate
the internal circuit breaker that operates the secondary bushing
what protective devices does a conventional transformer have
external switch; fused cut out, and surge arresters
single phase transformers are verstitile because
they can be installed individually or in banks to supply proper voltage
define protective equipment
anything that will de energize a line automatically
what causes fuses to blow
heat; amperage
surge arrestors are located in areas to
protect lines and equipment from surges and over voltage
how is a surge arrestor wired to the line
top is connected to a phase; bottom is connected to ground
what does a piece of equipment connected in series have to have
full power flow through it
key components of a gang operated switch
open all phases at same time; wired in series
reclosers do what
close a line after a temporary fault has cleared
what does the recloser do if the fault is permanent
locks out the de energized line until it is repaired
what percent of faults are temporary in nature
80%
when does a fault current occur
when energized conductor insulated from the ground comes in contact with another energized conductor or ground conductor
sectionalizer is a device that
clears faulted sections of line in coordination with a recloser
do sectionalizer open on a energized line or de energized line
de energized
what do voltage regulators do
allows utilities to maintain voltage levels within acceptable limit +/- 10%
4 characteristics of a voltage regulator
automatic trans installed in series with a line; all of the line current must pass through regulator; they are easily identified by the dial indicator located at the top of unit; not a piece of electrical equipment
2 characteristics of a capacitor bank
they have conductive plates separated by a dielectric (insulated) material; connected in parallel
gang operated switches do allow what; how are they wired
to mechanically open a three phase line; wired in series
distribution systems are designed to
minimize outage time to customers
what is the height range for the majority of distribution poles
35-55 feet
what can commercial and industrial customers experience when the power goes out
significant monetary losses
in what manner is protective equipment designed and coordinated in
which distinguishes temporary faults from permanent faults
the ability to take a section of line out of service and supply power from other circuits; loop fed
where are power transformers used
inside sub stations
underground risers consist of what
cut outs for opening the circuit; surge arresstors to protect the cables and equipment from over voltage conditions
what is an easement
areas designated or reserved for installation of distribution lines = franchise agreement; can be preserved by city or county; can require the utility to secure from the landowners
what is joint use
poles or underground trench use by other utility as ling as they comply with the NEC
protective equipment mainly consists of
fused cutout switches; reclosers; sectionalizers; and lighting arresters
9 components in a substation
power transformers; circuit breakers; disconnect switches; current and potential transformers; capacitors and reactors; voltage regulators; steel structures
a piece of equipment connected is series has what
full power coming in and out of it
a piece of equipment connected in parallel
not all power flows through it
as voltage increases so does
insulation
as amperage increases so does what
conductor
what cause a fault
phase to phase or phase to ground
3 pieces of equipment not connected in series
capacitor, surge arrestor, transformer
CPS transformer. list its functions; what is the handle's function; what is it connected to