Section 10 Digitrip Rms Retrofit - Eaton Cutler-Hammer Digitrip RMS 510 Instructions Manual

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SECTION 1O DIGITRIP RMS RETROFIT
SWITCHGEAR ASSEMBLY
APPLICATIONS
1O.1
Zone lnterlocking
Zone Selective lnterlocking (ZSl) capabilities are
available
with Digitrip RMS 510, 610, 810, & 910
Trip Units. ZSI provides positive system coordina-
tion by allowing the Breaker closest to the fault to
trip without any preset time
delay.
This
is achieved
by setting up the distribution system as shown
in
the adjacent diagram. The hard wired connection
between Trip Units sends a restraining signal
upstream, allowing
the
Breaker closest to the fault
to trip instantaneously.
ZSI's superior system coordination ensures that
the Breaker closest to the fault will trip without
preset time delays while reducing stress on the
distribution system.
10.1.1 Zone Selective
lnterlocking
Fig.
10-1
Zone Selective Interlocking
Fault
1
-
There are no interlocking signals.
The main Breaker Trip Unit will initiate the
trip
instantaneously.
Fault
2
-
The feeder Breaker Trip Unit will initiate
the trip instantaneously to clear the fault; and Zone
2
will send an interlocking signal to the Zone
1 Trip
Unit. The Zone
1
Trip Unit will begin to time out
and,
in
ihe event that the feeder Breaker in Zone 2
would not clear the fault. the main Breaker in Zone
'1 will clear the fault in 0.5 seconds.
Fault 3 -
The branch Breaker Trip Unit will initiate
the
trip
instantaneously to clear the fault; Zone 3
will send an interlocking signal to the Zone 2
Trip
Unit; and Zone
2 will send an interlocking signal
to
Zone
1 .
Zone 1 and Zone 2 Trip Units will begin to time out
and, in
the event that the branch breaker in Zone
3
would not clear the fault, the feeder breaker
in
Zone
2
will clear
the fault in 0.3 seconds. Similarly,
in
the event that the feeder breaker in Zone 2
would not clear the fault, the main breaker in Zone
1
will clear the fault
in 0.5 seconds.
NOTE: Digitrip
RMS Zone lnterlocking will trip the
Breaker instantaneously on Short Time (S)
or Ground Fault
(G) Delay Trip Functions
unless
it
is
defeated as described
in
the
following text.
For RMS 510 Basic Retrofit Kits, Zone lnterlock
functions are
not wired out from the Trip Unit.
The External Harness provided consists of a small
jumper plug that shods out the Zone lnterlock
signals at the Trip Unit.
For RMS 510 Zone, 610, 810, & 910 Retrofit Kits,
Zone lnterlock functions are available at
the
Cell
Harness assembly as shown in Figure
12-12.The
Breaker External Harness plugs into the Cell
Harness Assembly, which includes provisions
for
external wiring connections as shown in Figure
12-12. Shorting jumpers are provided at the Termi-
nal Block Assembly
to defeat the Zone lnterlock
functions. These jumpers can be removed and
selective Zone lnterlocking schemes applied.
Typical connection schemes for multiple Circuit
Breakers are shown in Figures 10-2 and 10-3.
i
5OOA P1CKUP
i
0.3
sEcoNDs
rME
DELAY
i.-2qNs
sg1s611yg
i
INTERLOCK WIRING
BREAKER NUMBER
1
GROUND
FAULT SETTING:
l2OOA PICKUP
0.5 SECONDS
TII\IE
DELAY
BREAKER NUMBER
2
GROUND FAULT SETTING:
i
BREAKER NUMBEB
3
--J
GROUND FAULT SETTING:
3OOA
PICKUP
NO TIME DELAY
Etfective 9/01
FlT.il