30
A DVAC® 3 8 K V I N STA LL ATI ON , OPE R ATI ON A N D M A I NTE N A NCE M A N UA L
—
Accessories
ADVAC® smart coils
First open coil
Shunt opening release (-MBO1) allows opening
command of apparatus to be enabled by remote
control. This release is suitable for both
instantaneous and permanent duty. However, an
auxiliary contact (-BGB1) de-energizes the coil after
the circuit breaker has opened. In the case of
instantaneous service, the current impulse must
last at least 100 ms. This release can be controlled
by the following devices: coil continuity control
(CCC), opening circuit supervision (TCS) or the
STU functionality control device (accessory
supplied on request).
Second open coil
Additional shunt opening release (-MBO2), similarly
to shunt opening release -MBO1, allows the opening
command of the apparatus to be transmitted by
remote control. It can be powered by the same
circuit as main shunt opening release -MBO1 or
by a circuit that is completely separate from release
-MBO1. This release is suitable for both permanent
and instantaneous duty. However, an auxiliary
contact (-BGB1) de-energizes it after the circuit
breaker has opened. To guarantee release action,
the current impulse must last at least 100 ms.
Continuity functionality can be checked with
a continuity control device (CCC), opening circuit
supervision (TCS) or the STU functionality control
device (supplied on request). Release -MBO2 has
the same electrical and operating characteristics
as release -MBO1
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 110 V to 250 V, and Itcs <50 mA for low
voltage coils from 24 V to 60 V). A simple resistor
can be sized for this purpose, depending on the
parameters of the TCS and the auxiliary voltage
range used.
