M ED I U M VO LTAG E P R O D U C T S
11
6.1 Notes on safety at work
•
Operation is only permissible by specially trained
personnel who are familiar with the characteristics
of the particular switching device.
•
Observe the relevant specifications as set out in
section 1.2.
•
Before a VM1-T on the withdrawable part is moved
it must be verified that the circuit breaker is
switched off. This is the case when the mechanical
position indicator 6 shows the position “O” and
when “READY” is shining on the READY lamp 2
while the breaker is supplied with auxiliary
voltage.
•
Due to safety reasons, the circuit breaker has to be
treated as “switched on” if the switching position
can not be clearly determined. In this case all high
voltage connections to the breaker have to be de-
energized and zero potential on the primary side
of the breaker has to be confirmed prior to
commissioning, operation, maintenance or repair
work.
•
The discharge energy of the storage capacitor is
greater than 350 mJ. The procedure for discharge
of the storage capacitor as set out in section 7.1 is
to be observed.
6.2 Preparatory activities (before
connecting the primary
voltage)
•
Check the circuit breaker, withdrawable part,
contact arms, insulating parts etc. for damage,
and restore to their proper condition if necessary.
•
Remove any dirt collected during transport,
storage or installation (particularly on the
insulating materials) as described in section 7.3.1.
•
Remove lifting lugs T (Figures 10/2, and 10/5).
•
Check the primary and secondary connections and
the protective earth conductor connection.
•
Check the connection of the main earthing bar
with the station earthing conductor (DIN VDE
0141).
•
Remove all material residues, foreign bodies and
tools from the switchgear.
•
Properly refit all covers, etc., removed during
assembly and testing processes.
•
Connect the supply voltage (Figures 9/15b, 10/7
and 10/8) - “READY” will shine. Inputs -RL1:
“Closing lock-out” and -MU: “Undervoltage
release” (if applicable) must be supplied with
power before the circuit breaker can be closed.
•
For this reason, an internal circuit applies a
voltage of 80 V to the input -RL1 (Figure 9/15b), as
soon as the storage capacitor is charged in as-
delivered condition of devices with no connector
wiring.
•
“READY” will shine even if the closing operation is
blocked by inputs -RL1 or -MU.
•
If no voltage is applied to input -RL1, closing is
impossible.
•
If no voltage is applied to input -MU, closing is
impossible in case of activated -MU and not
activated closing support.
•
Storage capacitors 26:
Following a (de-energised) storage period of more
than 2 years, reforming on initial start-up leads to
a temporary increase in current consumption at
the AC/DC converter, which is however below 2 A.
•
Check mechanical and electrical interlocks for
effectiveness, without using force.
•
Perform test closing and opening of the circuit
breaker by pressing push-buttons 3 and 4 (see
Figure 9/16).
•
On motor-driven withdrawable parts, check the
direction of rotation of the travel motors as
described in section 7.5.3.
•
For any further questions on the functions of the
withdrawable circuit breaker part and its testing,
see section 7.5.
•
Instruct the local operators in the fundamental
details of regular handling of the switchgear.
6.3 Earthing
For the fixed version circuit breaker, carry out
earthing by means of the special screw marked with
the relative symbol.
Clean and degrease the area around the screw to a
diameter of about 30 mm and, on completion of
assembly, cover the joint again with Vaseline grease.
Use a conductor (busbar or braid) with a cross-
section conforming to the Standards in force.
—
6. Commissioning / Operation
Содержание VM1-T
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