3 Opening solenoid (-MBO3)
The opening solenoid (-MBO3) is a special
demagnetizing release for use in conjunction with
self-supplied overcurrent protection relays.
It is situated in the operating mechanism (in the
left-hand side) and is not an alternative to the
additional shunt opening release (-MBO2).
It is only available for VD4G-25 circuit-breakers.
If this accessory is required, it must be specified
when ordering since it cannot be installed by the
customer at a later date.
Note: for use in conjunction with a protection relay
ask for document: Data sheet 1VCD600854.
The opening solenoid (-MBO3) is available in two
versions:
• For D.C. (release by discharging energy stored in
protection relay against overcurrent of the self-
supplied type)
• For A.C. (release by means of energy supplied by
an adder transformer on the secondaries of the
protection current transformers) (the adder CT is
at the customer’s charge)
4 Shunt closing release (-MBC)
Allows the apparatus to be closed by remote control.
This release is suitable for both instantaneous and
permanent duty. An auxiliary contact to de-energize
it after the circuit-breaker has closed is not envis-
aged.
The permanently supplied release provides the elec-
trical anti-pumping function with both electrical
opening and re-closing commands maintained. To
guarantee the closing action, the current impulse
must last at least 100 ms.
If there is the same supply voltage for shunt closing
release -MBC and under-voltage release -MBU and
the circuit-breaker must close automatically when
auxiliary voltage returns, there must be a delay of at
least 50 ms between under-voltage release energiz-
ing and energizing of the shunt closing release to al-
low the closing operation to take place.
Continuity functionality can be checked with a con-
tinuity control device (CCC), opening circuit supervi-
sion device (TCS)(*) or the STU functionality control
device (see accessory 19, supplied on request).
Characteristics
Un
48 - 110 ... 125 - 220 ... 250 Vdc
Un
110 ... 125 - 220 ... 250 Vac
Operating limits
in accordance with IEC/IEEE
62271-37-013
Power at inrush (Ps)
60...100 W / VA
Continuous power
consumption (Pc)
1.5 W
Electronics self-consumption
(no coil supplied); value
independent of voltage
applied
1.5 mA
Opening time
33...60 ms
I
nsulation voltage
2000 V 50 Hz (for 1 min)
(*) The minimum current
that the relay with TCS
function (used for
monitoring coil
continuity) detects as a
condition denoting that
the trip circuit is
operating correctly
(specified for each relay in
the relative manual), must
be sensibly higher than
the current consumption
of the actual coil (~1.5
mA).
If this fails to occur,
always add, in parallel to
the TCS, a circuit able to
absorb sufficient current
to compensate the gap
while preventing the total
current in the TCS circuit
from rising above the
maximum threshold (Itcs
< 10 mA for High Voltage
coils - from 110V to 250V,
and Itcs < 50 mA for Low
Voltage coils from 24 V to
60 V).
A simple resistor can be
sized for the purpose,
depending on the
parameters of the TCS
and the auxiliary voltage
range used.
M ED I U M VO LTAG E PRO D U C T S
15
