The daily Gate City. [volume] (Keokuk, Iowa) 1855-1916, 1915-04-22

| sistance, will hold the voltage down
to approximately normal. The arc
rises and ruptures on the discharge
horns in the usual manner.
! With a potential rise of higher en-
] ergy capacity, the current flow
across the gap and resistance may be
! insufficient to hold the voltage GOWN.
The arc will then go across to the
next lower step, cutting out one re-
| sistance section and a greater cur
rent will flow. If this current flow
is still insufficient to hold the voltage
down to a safe value, the next lower
step will arc across. This action will
continue, depending upon the energy
capacity of the potential rise.
Under abnormal conditions, the arc
bridges the lowest gap or resistance
step, and if the high value disturb
ance continues for a sufficient time,
the carbon-tetrachloride fuse opens.
This absolute limiting device will
clear the system without effecting
the load supply fuse. With the short
circuit fuse blown, the arrester is still
in operating condition, the only
change being that the lowest step
has some series resistance until the
blown fuse has been replaced.
The S. & c.. arrester action can
we'll be compared with steam boiler
which has a number of safety values
each of different effective openings
and each set at different pressure,
those of the smallest opening being
set at the lowest pressure, and those
Of the largest opening, being set at
the highest pressure.
A boiler carrying normal pres.
sure of zoe lbs. might have one inch
pop valve set at 225 lbs, inch
set at ESQ lbs, etc. and 10 inch set
at 300 lbs. II the over-pressure can
be relieved by means Of the one inch
valve set at 225 lbs, it is more de-
sure by the ten inch valve set at 800
lbs. TsIipt4s
The same reasoning applies to the
arrester, and with the arrangement
shown, over-pressures can be re-
lieved with minimum disturbance to
the system. ltTQb sn
An advantage of the tapering gap
construction Is that 1t secures a
chimney effect" and the arc rises
rapidly over the resistance portion Of
the arrester. finally breaking the d.
verging horns.
Handling Satisfaction Transformers.
It is now, recognized that some
means should be provided for quick
Iy, easily and economically handling
the transformers. These units are
comparatively heavy, and unless suit
able methods of handling are prov1d-
ed, the expense will be a consider
able item. For medium capacity sta
tions, the construction shown in the
accompanying illustrations will be
found convenient.
Near the top Of the sub-station
tower are located three pivoted 1ib
cranes. The single jib crane is pivot
ed on one corner support Of the tow
err, the double jib cranes being To-
Gated on the opposite corner. Zach
jib is equipped with heavy steel
loop in which can be placed the
hoisting tackle hook.
The main transformer platform.
consisting OF two heavy 'T'' beams,
is provided with a transfer table,
which travels the full length Of the
main platform. Limit stops at both
ends of the "1'' beams prevent the
transfer table leaving the track when
at either extreme end position.
Stimulate Desire.
Often, it is claimed that the farm.
er or small community man. is slow
to take up the use of electricity. This
same class, at first, gave the automo-
bile scant consideration-but, a
proper education and sales campaign,
has made the farmer an important
factor in the automobile field.
The desire for electric service sim
ply needs stimulation, and once its
decreased fire risks,
real economy, etc, are understood,
the way is open. One Of the real OBJ
stacles to increasing transmission Line
revenue, is the indifference to what
might be termed sales spirit. In
short, after consumer is connected,
the transmission company too often
forgets the possibility Of increasing
his load. 1t is not good policy to
spend all the time In securing new