ABB VM1-T Manual page 7

M E D I U M V O LTA G E P R O D U C T S
This input switches the VM1-T off if the voltage
applied falls below the tolerance range stipulated in
IEC 62271.
The nominal value of the voltage to be monitored is
set at the works in accordance with the
specification in the order. In order to prevent
switch-off when the voltage briefly falls below the
specified level (e.g. on motor start-up), a tolerance
time can additionally be set.
If no voltage is applied to -MU, the VM1-T cannot be
closed normally. However a closing support function
is provided, that can enable the closing operation
even if no voltage is applied to -MU. If after this
closing operation no voltage is applied to -MU, the
VM1-T will switch off.
The function of -MU can on the control module be
deactivated if it is not required. If the function of
-MU is deactivated, the VM1-T can be opened and
closed without any voltage being applied.
For the coding of the DIP switches, see figure 9/15a.
• Monitoring of the closing and opening coil of the
actuator
This function monitors the closing and opening coil
of the actuator for cable breakage.
If such a breakage is detected, the "READY" lamp on
the front of he switching device goes out and
corresponding signals (-DR, -DN) are issued.
• Additional contacts for position signalling
An additional pair of NO contacts to signal the ON
and OFF positions are made available by the
controller (-DO2, -DC2).
• Direct opening without microprocessor is
supported
The second opening input -MO2 is designed in such
a way that an opening command is executed directly
without being passed through the microprocessor.
3.1.5 The "READY" lamp monitors the following
conditions:
• supply of auxiliary power to the VM1-T circuit
breaker (see also section 6.2),
• detection of a defined ON or OFF position by the
position sensors,
• monitoring of the controlled function of the
microprocessor – Watchdog,
• sufficient voltage at the capacitors for the next
switching operation (see also section 2.1.2) and
• continuity of the actuator coils.
The "READY" lamp does not monitor the status of
inputs -RL1 and -MU. Therefore, it may happen that
the VM1 will not perform a closing operation even
though "READY" is shining. In that case, the status
of inputs -RL1 and -MU has to be checked.
A flashing "READY" lamp signals recharging of the
capacitor. Switching readiness is enabled during
that time.
3.1.6 Blocking magnet -RL2
(Figure 9/27)
The optional blocking magnet prevents the
withdrawable part from being moved when no
supply voltage is applied or when the CB is not in
OFF position. This interlock is cancelled by applying
supply voltage to blocking magnet -RL2.
3.2 Circuit diagrams for circuit
breaker withdrawable
assemblies
(Figures 9/14, 10/7 and 10/8)
• The circuit diagrams, shown in figures 10/7 and
10/8, comprise the basic equipment and all
possible additional equipment for the various
VM1-T types. The scope of equipment possible for
each type is shown in the relevant switching
device list. The equipment fitted in individual
cases is detailed in the order documents.
Panel type Plug type
58-pole
UniGear type ZS1
control wiring plug
The possible coding of a 58-pole plug is shown in
figure 9/14.
7
Figure no.
10/7 and 10/8