Western Electric 407A-4, Инструкция по эксплуатации

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Fus es
then the a-c trip elements in the b reaker have
operated t o open the breaker or the c ontrol ci r­
cuit for the b reaker has opened.
E51F - '•Protective Circuit11 is extinguished by the
operation of S3D whi ch energiz es SlOA to momen­
tarily remove the carrier .
SUPPLEMENT.ARY NOTES
Apparatu s Information
The only fuses used in the e quipment are as listed in
Tab le 8 . Each fus e should b e tested for continuity b efore
placing in the fus e mounting.
Western Electric Type Kl lamps are us ed for indicating
lamps in the C ontrol Unit and Oscillator Amplifier Unit .
The 116 Tool is provided for removing these lamps and 319B
Tool for removing the la.mp caps .
General Electric Maz da No. 46 Lamps are us ed to il­
luminate the meters .
Vacuum Tubes
The types of vacuum tub es us ed in the 407A-4 Equipment
and their corresponding designations are given
in
Table 9 .
Rectifier Tubes
The life of the 2 55B and 315A vacuum tub es is greatly
affected by the care that is taken to make certain that
these tub es have been thoroughly warme d before the applica­
tion of plate voltage . The relay S2F which is inc orporate d
in the c ontrol circuit of this equ ipment prevents the ap­
plicati on of plate voltage for 3 minutes
(
for 50-kw opera­
ti on only
)
, but is advantageous when time permits to us e a
longer preheating time , particularly when the amb ient tem­
perature is low. Tubes which have not b een operated for 48
83