Toshiba VK-6M32A Installation Operation & Maintenance page 58

lvlav.
31
2012
9:
24Al\4
No,
1530
P
59
Page
56
GONVERSIONS
VMD
The VMD {Vacuum Circuir Bresker Monitoring Device}
is a
device
used
to monitor the clrcuit breeksr
during
a
ctoiing
oparetlon lnhiated by
an
alactrical eignal and will trip the circuit blEaker open $hould
a
dow
or incorhplete clo$ing operation
occur.
Tlts
rafEty
davlcE
rhould be lnstslled on any
TorHba
clrcuh breaker udlked ln a corwerslon that
uses
the mAifi Opeflidg-Closing $haft
for any porpos€8
other dlen the
mrmal open+lose
oparadon or
1fie
oFeradon
ol
a
Toshlba MOC.
lTWmil
Do
not ovcrload rhe
circuit breaker operatlng mechanlsm, Slow
or
lncomplete oloslng
of dle clrcult bteaket can oau9e
fire
Nfid
explotion, retulting in aavsla injury, d6ath
8nd
plopitty
damege.
The VMD monitors
ths pedormance
of the circuit breaker dutlng
the
closing operation from
an
elecric€l
signal. lf the circuit breaker faile to cloae
within
lOomsec after an electrical closing
Sigttal
hag been
sent, the VMD will send an electrioal signal to a sscondary trip coil. This coil will trip the
chcuit
breakar open
at any physical poinr of rhe closing operation and r€l€as€ any en€tgy stored in
the claiing springs, thus
rEducing
tha
chancEs
of o serious electrical failute.
Once
the
vMD
has
performed
o
tripping opararion, it will eut
the control
circuit powe/
to the charging
motor thus preventing the closing springs
from
being rachatged. This
will
tandBr
the c:rcuit
breaker
temgorarily inoperable.
The
VMD will reset automatically only sftsr the control circuit powBr has bssn
idterru pted
.
An indicating
ligh
thar prorrudes elightly through tho circuit
breaker
lront cover
will
be illuminated
if rhs VMD
h€8 p€rform€d a
trlpplng op€ration.
Should
the VMD trip the circuh breaker open,
the circuit breakel must be removed from service and
a
thotough inspection
made
to determine lhe cause of tha elow or incomplete closing of the circuit
br6akor. The cause
of the slow or
incomplete closing mu$t be correctsd bdfore placing tho circuit
bro|ker back in servica,
Do
not lesct thc
vltD
or attemDt circuit bfeaker op€mtion
o,
i
comFlete
cloling has baan determlned and corrected' Fallule
to
do
untl
th6
cauaa
of dow
$o oan Cluse
fire
and
exploslon.
r6dtirrg
ln $evse iniury, detth
anal
ptopafty damagc'
Refer
to the VMD manual GF077690
for
more intormation ragarding opetEtion and maintenance'