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what is a manhole where both transmission and distro ducts terminate is called what

a T & D manhole

in an area where it is necessary to avoid disrupting streets and lawns it is most likely that the cable will be ?

buried with guided underground boring

on underground systems it is more costly to locate and repair faults when?

compared to overhead systems

ducts running from manhole to manhole can be made of?

concrete

primary cables cant be buried in the same trench with secondary cables

false

the term "joint construction" of a pole or an underground system refers to an installation where several utilities share the facilities but not the cost

false

advantages of underground systems compared to overhead are?

less vulnerable to damage from wind, ice and cars. more aesthetically pleasing, safer for the public

when are underground systems commonly used?

the appearance of overhead lines is undesirable. the hazard of exposed high voltage lines is too great. space is not available for overhead lines.

a disadvantage of underground systems compared to overhead is that

theyre more expensive to build

accidental dig ins, corrosion or chemical action, and earthquakes are potential problems that damage underground systems

true

fault indicators minimize the duration of outages because they aid in finding the trouble location

true

loop type feed design makes it possible to restore service to certain customers while making cable repairs

true

some underground cables may be burried directly in the ground with only an envelope of sand around them

true

the direct bury system is used mostly in underground residential distro systems

true

the underground riser provides fused protection and an isolating device for the underground cable

true

ducts for transmission lines are sometimes referred to as?

trunk ducts or subterranean feeders

the letters URD stand for?

underground residential distribution

what is oil or gas filled cable used to permit

underground transmission conductors with line voltages up to 500kilovolts

can a pad mounted transformer be used in URD

yes

can a system have sections of overhead and underground or not?

yes