Field Discharge Switch - Westinghouse De-ion DB-15 Instructions Manual

When the series coil current
ward direction, armature movement is prevented by
a stop. When the series coil current
the armature rotates in the opposite direction to
trip the breaker.
25
to percent reverse current, based on normal
current rating.
After tripping, the reverse current armature is
reset by opening the potential coil circuit. For this
purpose an "a" contact of the breaker auxiliary
switch should be connected in series with the poten­
tial coil.
•
FIG. 15. Auxiliary Switch-Location
in
is
flowing
is
Calibration adjustment covers
R E A R
I N S U L A T I O N ROTORS
1 8 3
FIG. lSA. Auxiliary Switch-Construction Details
laspection.
the for­
push backward on the spring stud located on the
bottom of the armature, to trip the breaker.
reversed,
armature should move without friction, and should
5
have approximately 'h2-inch overtravel after trip­
ping.
Final inspection should be made electrically, after
the circuit connections are complete as shown in
8,
Fig. page
�aintenance.
breaker and repeat the mechanical inspection given
above. Check for loose bolts and open circuit in
potential coil.
DBF-6 FIELD DISCHARGE SWITCH
The field discharge switch is ordinarily used
with a two-pole breaker, and mounts on the center
moulded pole unit base. (See Fig. 14). The switch
is shipped with the gap setting shown in Fig. 14,
for generator field protection.
setting can be reduced to zero or set to open after
the breaker contacts close,
is always supplied to interrupt motor starling second­
ary currents.
Inspection.
breaker manually and check for freedom of motion.
The break distance is adjusted by loosening the lock
nut and turning the sleeve in or out. Always leave
a slight gap at the slop surface.
�aintenance.
er, clean the contacts
separation and adjust
bolts.
F R O N T I N S U L A T I O N R O T O R
F l N G E R S
1 8 4
R O T O R
1 8 5
F RO N T C O V E R
1 8 6
"DB" AIR CIRCUIT BREAKERS
Close the breaker manually, and
22.
Remove all power from the
However, the gap
if An
desired.
Remove the arc chute, close the
Remove power from the break-
if
necessary, check the contact
if
necessary. Check for loose
The
arc chute
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