Defeata Ble Ground-Fault Protection - GE Power Break II Manual

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MicroVersaTripPius
Defeatable G rou nd-Fa u lt Protection (Optiona ll­
Not U L Listed
A defeato ble g round-fault p rotection is offered for users who
wont the ability to enable or disable g round-fa u lt protec­
tion depending on special circumsta nces. When this type of
g round-fault protection is ordered, in addition to the normal
g round-fault settings, the user con enable or disable ground­
fa ult protection d u ring progra m ming. To d isable this kind of
g round-fa ult p rotection, set the delay to OFF.
Zone Selective I nterlocking (Optional)
Trad itional means of obtaining selectivity between main and
feeder breakers is to set the furthest downstream device
with the lowest time delays, and increase time delays of
u pstream devices. The disa dva ntage of this is that u pstream
portions of the system m ust endure h i g h values of fau lt cur­
rent until time-out occurs.
"Output" from Trip unit
"Input" to Trip unit
ZSIM No.1
Upstream
Downstream
Connections Connection s
- Bus Wiring
--
M u lti-zone sel ective interlocking
and PM™ Trip Units
MicroVersoTrip Plus™ and MicroVersoTrip PM™ trip units
provide coordination between the fi rst breaker and the im­
mediate u pstream breaker. When the downstream breaker
detects a fa ult, it signals the upstream device to shift to its
preset time delay bond, a l lowi ng the downstream device to
clear the fa ult. Without a signal from a downstream brea ker,
on u pstream breaker will respond on the minimum delay
bond. For a fau lt between these two breakers, the upstream
would clear the fault on the minimum delay bond since n o
sig nal i s being sent b y t h e downstream breaker.
Zone Selective i nterlocking is ava i lable for either g round fault
only, or both g round-fault and short-ti me functions. The
zone selective i nterlocking feature requi res a zone selective
interlock module (ZS I M ) catalog num ber TI M l. The module is
on i ntermediate control device used between upstream and
downstream circuit b reakers to commu nicate with the short­
time and g round-fault zone selective interlock functions of
the M icroVersoTrip Plus and MicroVersoTrip PM units. The
module req uires 120/208/240 VAC, 15 VA maxi mum.
Operation of MicroVersaTrip PM Trip Units
M icroVersoTri p PM trip un its odd com m u nications capability
with remote h ost computers and the G E POWER LEADERTM
Power Management System. I n a d d ition, the user can choose
to odd metering, protective relaying or both. In the block dia­
g ra m (page 2 0) of the M icroVersoTrip PM trip unit, note that
there o re two a dditional sets of i n p uts- voltage inputs from
each p ho se a n d a +24 Vdc input from on external power
supply. Additionally, there is a commu nication input/output
link to the POWE R LEADER system.
Voltage I n puts
Voltage inputs to the MicroVersoTrip PM trip unit o re required
for both metering and protective relays. Voltage in puts
require three delta or wye-connected potential transformers
with 120 Voc secondaries, and an external voltage module
that further conditions the voltage signals for use by the trip
unit's microprocessor. A single set of external voltage mod­
ules con serve the req uirements of u p to 20 trip un its.
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