VAMP 221
Arc protection system
Technical description
VAMP Ltd
10
VAMP 24h Technical Support: +358 (0)20 753 3264
VM221.EN013
The output trip relays of the central unit can also operate
selectively during arc faults in different protection zones.
The output trip relays of the I/O units can also be used for
tripping in different protection zones. Each I/O unit has one
output trip relay, which trips either in faults in its own zone
(VAM 10L and VAM 3L / VAM 3LX) or in the programmed zone
(VAM 4C).
If necessary, trips can be multiplied using the multiplying relay
VAR 4CE.
2.4.
Self-supervision
The system monitors the microcontroller and related circuit
operation, and program execution with a separate supervision
circuit. In addition to system supervision, the circuit attempts
to re-start the microcontroller in the event of a fault. If the re-
start fails, the supervision circuit gives a self-supervision alarm
on a permanent internal fault. In case of am microcontroller
failure the trip functions still works but latching is blocked.
Whenever the supervision circuit detects a permanent fault in
any system component it ignores activation signals coming
from this component e.g. faulty arc sensor.
The supervision circuit also monitors the internal operating
voltage. In the event of loss of operating voltage in the central
unit, the system automatically gives an IF alarm, since the IF
output relay operates on steady-state current; in other words,
the IF relay is actuated when the operating voltage is on and
within the permitted limits.
2.5.
BI/O bus interface
All VAMP 221 Arc Protection System units can receive or
transmit light and/or current criteria (depending on the unit)
on the BI/O bus.
VAMP 221 can send BI/O information to two central units or
two protection relays. If there are more than two recipients of
BI/O information or the length of the BI/O bus exceeds 100 m,
the BI/O bus must be equipped with a line amplifier as shown
in the figure below.
