Western Electric 407A-4, Инструкция по эксплуатации

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plate transformer T58P during 5-kw emergency operation.
S63P and S64P are contactors which transfer the 460-
volt output of the Plate Regulator between the high-voltage
transformers T53P, T54P, T55P
(
for 50-kw operation
)
and
T58P
(
for 5-kw emergency operation
)
. These contactors are
located in auxiliary power distri bution cabinet DP51P.
For 50-kw operation, L51P and C51P are the inductive
and capacitive elements of the power-amplifier plate-supply
filter. PR52P is an oil-immersed thyrite surge arrester,
which under transient conditions absorbs the energy stored
in L51P, thus avoiding destructively high voltages. Re­
sistor R55P prevents C51P from drawing an excessive charg­
ing current when high voltage is applied. This resistor is
automatically shorted by contactor S51P after C51P is
charged to the operating voltage. R56P and R57P are surge­
limiting resistors which prevent excessive currents from
flowing under trouble conditions. D57P and D58P are dis­
connect switches
•
.Any accumulated dust should occasionally be blown out
of coil L51P by dry compressed air. The proper oil level
should be maintained by PR52P.
For 5-kw
L52P and C52P form the
high-voltage filter. R58P is the charging-current limiting
resistor for C52P, and is shorted by contactor S67P after
C52P is fully charged.
D-99119 Rectifier Tube Unit
(
Unit H, Schematic 2
)
Circuit Description
This unit contains the six tubes VlH to V6H inclusive
connected in a three-phase full-wave bridge type rectifier
circuit. The tubes convert the three-phase high-voltage
power furnished by the th ree-phase supply transformers into
10