L&T Electrical & Automation OMEGA, Manual

Page: 73 / 135

Breaker Accessories:
Modularity, the key design aspect of OMEGA ACBs facilitates the quick fixing & removal of several breaker mounted
accessories such as CR, SR, UVR, Auxiliary contact blocks & various indicating micro-switches. These accessories are
located on the front top-side of breaker mechanism & have specified positions.
1) Auxiliary Contact Block:
Auxiliary Contact Block contains the change-
over switch contacts in combination of 4 units of 1NO+1NC each. Auxiliary
contact block reflects the breaker ON/OFF state in control circuit.
3)
Closing Release (CR):
Closing Release remotely closes the Circuit Breaker
if the spring mechanism is already charged. Closing Releases in Omega
Air-circuit breakers come with inbuilt Electrical anti-pumping feature. Inbuilt
electrical anti-pumping feature prevents auto-reclosing of Circuit Breaker on
faults. Anti-pumping relay cancels the persistent closing signal after successful
completion of the closing operation.
24V
10A
10A
Operational voltage (Ue)
In (DC-12)
In (DC-13)
40V
8A
4A
110V
3.5A
1.2A
220V
1A
0.4A
upto 24V
10A
6A
Operational voltage (Ue)
In (AC-12) at 50/60 Hz
In (AC-15) at 50/60 Hz
110V
10A
6A
220/230V
10A
6A
400V
10A
4A
2) Shunt Release (SR):
Shunt Release when energized opens the breaker
instantaneously. Omega ACBs offer general purpose Shunt Release which can
reliably trip the Circuit Breaker through external trip command.
Power consumption
200VA for 0.5 sec
200W for 0.5 sec
Operating range
70-110% of Ue
70-110% of Ue
Operational voltage (Ue)
110, 240, 415V AC at 50/60Hz
24, 30, 48, 60, 110, 125, 220, 250V DC
Operating range
85-110% of Ue
85-110% of Ue
Power consumption
200VA for 0.5 sec
200W for 0.5 sec
Operational voltage (Ue)
110, 240, 415V AC at 50/60Hz
24, 30, 48, 60, 110, 125, 220, 250V DC
Closing
Release Auxiliary Contact
Block
Under-voltage
Release
Controller
Under-voltage
Release
Shunt
Release
Operation
Counter
6
2 3 4 5
1
Under-voltage
Trip Indication
Common
Fault Indication
Shunt Trip
Indication
C1
C2
TCS
A1 A2
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4) Under-voltage Release + Delay Module (UVR):
The Under-
voltage Release causes the Circuit Breaker to open if the operational voltage
falls to a value between 35% and 70% of its rated voltage or not applied.
UV Release mechanically locks the closing of breaker & it makes it impossible
to close the Circuit breaker, either manually or electrically. The Circuit breaker
can be closed with operation voltage of 85-110% of its rated value.
UV Release can be used for monitoring the voltage in the primary (power
circuit) or secondary (control circuits) circuits or can be used for electrical
interlocking scheme (for DG synchronization, paralleling of transformers etc).
In order to avoid the nuisance tripping of the circuit breaker during short
voltage dips, UV release comes with the UV-delay module. Operation of UVR
can be delayed between 0 to 5 secs. in steps of 0-1-3-5 sec.
D1
D2
5) Electrical Charging Device (ECD):
Electrical Charging Device
automatically charges the closing springs of the circuit breaker operating
mechanism. After Circuit Breaker closing operation, the geared motor
immediately recharges the closing spring. Thus instantaneous re-closing of
the circuit breaker is possible following opening operation. The closing springs
can also be charged manually (using the spring-mechanism charging handle)
in the event of an auxiliary power supply failure or during maintenance work.
6) Operation Counter:
The Operation Counter indicates the number of
operating cycles the Circuit breaker has been subjected to and it is visible on the
Circuit breaker front-facia. It is compatible with manual and electrical control
functions. Counter readings serve as a guide for maintenance & inspection.
Operating range
85-110% of Ue
85-110% of Ue
Power consumption
300VA for 1 sec
300W for 1 sec
Operational voltage (Ue)
110, 240, 415V AC at 50/60Hz
24, 30, 48, 60, 110, 220, 250V DC
7) Micro-switches for electrical indications:
a. Common Fault Indication (CFI): CFI provides the
electrical indication of circuit breaker tripping due to
operation of protection & control unit.
b. Under-Voltage Release Trip Indication: Under-voltage
Release Trip Indication micro-switch provides electrical
indication of circuit breaker tripping with the operation of
under-voltage release.
c. Shunt Release Trip Indication: Shunt Release Trip
Indication micro-switch provides electrical indication of circuit breaker tripping with operation of shunt
release.
d. Spring Charging Indication: Spring Charging Indication micro-switch provides the electrical indication
whether main mechanism spring is charged or not.
e. Ready-To-Close Indication (RTC): RTC takes into account all the safety parameters that are part of the
control & monitoring system of electrical installation. OMEGA RTC allows the circuit breaker to close only if
following conditions are met:
ü ü
ü ü
ü
ü
ü
Main spring is charged All Arc-chutes are properly placed
Circuit Breaker is OFF Mechanical trip indication lever on release is
reset
Shunt release is de-energized
Racking shutter is closed
Under-Voltage release is energized
24, 30, 48, 110, 220 V DC
110, 220, 240, 415 V AC
50Hz / 60Hz
85 - 110%
200 VA max, 3s
200 W max, 3s
UVR
(Delay Setting-0,1,
3 & 5 sec)
N o r m a l V o l t a g e
T y p e
O p e r a t i n g
L i m i t
S h o r t - t i m e P o w e r
C o n s u m p t i o n
72 Accessories