Western Electric 407A-4, Инструкция по эксплуатации

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tactor S58P. The operation of S58P energizes the power am­
plifier filaments through the s tarting res istors R51P, R52P
and R53P. As the filaments heat up, increasing in resis ­
tanc e , the proportion of the supply voltage appearing acros s
the f ilament trans formers also increases . Relay S6 2P, con­
nected across one phase of the filament trans forme r supply,
is adjusted to operate when the vo ltage
(
and hence the re­
s istance of the filaments
)
has increased to a value at which
it is safe to apply full voltage to the fi laments . The
operation of S 6 2P connects the coil of contactor S59P across
one phas e of the power supply. The operation of S 59P shorts
out the s tarting resis tors R51 -53P.
Rectifier Filaments and B ias
Clos ing DlF "Rectifi er Filaments
11
supplies 230V through
terminals 21F, 22F and 23F to terminal 15 of the dis tribu­
tion panel and operates contactor S57P . Assuming switch
D21H to b e clos ed, the filament circuits of rectifier units
H and
K
are energized. The fi lament c ircuit of Unit G is
energiz ed at reduced voltage assuming switch D5G to be open,
and at full voltage if D5G is closed. For 50-kw operation,
the 230-volt circuit is continue d through the auxiliary con­
tacts of S57P to the c ontacts of relay S8H which is operated
when the fi laments of rectifier units H and
K
are energi z ed
and the b lower motor switch D5H is close d. For 5-kw opera­
tion, the c ontrol circuit extends through the c ontacts of
relay Sl8F, which is operated when switch D5G is c losed to
energi z e the filaments of rectifier unit G. The control
circuit then pas s e s through the 50-5 kw trans fer switch
D6G and returns to terminal 24F, operating hour meter M5F
and light ing E5F - "Rectifier Filaments . " Delay relay S2F
is energiz ed
(
50-kw operation only
)
, and 11 5 volts is sup­
plied through LlF to terminals 1 and 2 of Sl6F . A detailed
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