El Paso daily herald. (El Paso, Tex.) 1881-1901, 1900-08-16
ELECTRIC SYSTEMS


The Underground Trolley Sys-
tenn Offset In the Case OF A
Small City BY the Increased
First Cost.
Considerable speculation exists In
FL Paso concerning the kind OF electric
railroad that is to be built here. The
SURVEYS are now being made and peo-
nile have begun to ask whether the line
is to be operated by underground or
overhead trolley.
Electric street railways In the On!teo
States are usually operated by what
in known as the direct current, SUI
volt constant potential, series system.
In practice there are several
methods of installing the wiring and
apparatus for she operation OF electric
railways. Only two OF the above
mentioned methods can be considered
as the others have bad only Limited
practical application.
The first system is what ia known rs
the grounded or earth return series
system, the current being carrlea
from the positive terminal OF the
generator through q trolley wire car
ried on poles to the end OF the railway
line or to the end of section OF the
line, the return being made through
negative terminal of the generator.
The current for the motors on the cars
ia taken from the trolley wire by
means of q trolley, pole, harp and
wheel, which are carried above the
car. and which are in electrical con-
uection with the motors of the cars.
The current at 500 volts passes from
the trolley wire to the trolley wheel:
from the trolley wheel to the series OF
from the motor through the bonded
rail and the earth to the generator
terminal.
The second system is what is known
"a the all metallic circuit series system
| In which the current at pofentlal OF
500 volts leaves the positive terminal
of the generator, is carried by means
of feeder or other currens supply
wire to the end of the line or to the
end of q section of the railway line and
returns to the negative terminal OF the
generator through trolley.
This trolley wire is usually run In q
slotted conduit. from which it 1s care
fully insulated, the conduit Ia laid In
| the center of the track under ground.
Current for the series of car motors ls
taken from the trolley wire In the con-
duit bv means of q trolley pole, harp
and wheel of other mechanical adapta-
4
bottom or the car through the slot In
the conduit and makes electrical con
nec.ion between the trolley wire and
the motors on the cars by means OF
the trolley wheel.
| The advantage of the first system ls
due 10 the comparative simplicity and
| cheeppess at which it can be insta leo
and operated Its disadvantages rlsee
from the electrolytic corros1on OF gas
| and water pipes, due to the leakage Of
the current from the bonded rail re
turn to the said gas and water pipes
| any where near 1T. 49,
| In order to avoid as far as posi- oi
the electrolytic corrosion OF gas an q
| water pipes, section IL, article N, OF
the ordinance recently passed oy the
city council of Ri Poo reads as !ollows
| tFor the diminutiop CT eleotrolytlc
corrosiou of underground metal wO X,
return ground wires must be go arrang'
ed that the difference of potential be-
tween the grounded dynamo terminal
| and any poiut on the return circuit
will not exceed twenty-five VOLTS"
The advantage of the second system
lies in the fact that it does away with
overhead wiring altogether in the
event it may be so desired and that as
no return is made through the rail- or
the ground, no electrolytic corrosion
of as and water pipes takes place.
The disadvantage lies In the greatly
added first cost of installing such a
| aystem, due to the cost OF the conduit
| and the labor of installing same. and
the cost of tina additional copper wire
| necessary.
The Ell Paso system will be the over
head trolley.