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ELECTRIC SERVICE SUPPL COMPANY
r^
the iip]jer spool bracket by
means of a heavy copper strip,
K, on the base. By the use of
this copper connection, the
lii^htning discharge does not
even flow through the flexible
cable connecting the upper end
of the movable plunger with
band E : cutting out the inductance
of this flexible cable has
a])]3reciably increased the sen-
siti\-eness of the Arrester.
On grounded electric railway
circuits, after a lightning discharge
has broken down and
arced over the air gap, a path
DiaKram No, .\ '^ oftered through the Arrester
for normal or dynamic current
from line to ground, which must lie instantly cut ol¥ by the Arrester.
The path for this normal or line current is as shown by the dashed
line ; it, the same as the lightning discharge, crosses upper air gap B,
thence flowing through section CD of the resistance rod. Reaching
point D it is shunted into the magnet coil H,—for reasons see page 39,
pertaining to operation of the type CE Arrester—flows through this
winding to point E, thence through flexible lead, iron plunger J
(which rests on a carbon button M connected to ground binding post
X), thence to ground.
This flow I if line current through coil II, energizes the n'on
plunger J, which rises upward in the cuil, upening the circuit between
the lower end of the plunger and the carbon button M. This cuts olT
the flow of line current to ground, the arc at gap B dies out. the coil
loses its energy and the i)lunger returns by gravity to its normal
positicm. The .\rrester is instantly ready for another discharge.
Xote that the arc is ncit limken at the air gap, but inside a fibre
tul)e helween iron an