Inspection And Functional Testing; Circuit-Breaker In General; Magnetic Actuator Operating Mechanism - ABB VM1 Instruction Manual

The servicing intervals and scope are determined
by the environmental influences, the switching
frequency and the number of short-circuit breaking
operations.
Note:
The following must be observed for all maintenance
work:
• The relevant specifications in section 1.2.2.
• Notes on safety at work in section 6.1
• Standards and specifications in the country of
installation.
Maintenance work may only be performed by fully
trained personnel, observing all the relevant safety
regulations. It is recommended that ABB after-
sales service personnel should be called in, at least
during the performance of servicing and repair
work.
While the work is in progress, and if the work
permits, all supply voltage sources must also be
disconnected and
connection.
Note:
In order to prevent accidents (particularly injury to
hands!) extreme care should be taken during all
repair work on
especially with front plate 1.1 removed.
The energy of the storage capacitor can be
released uncontrollably during incorrect handling!
Procedure for capacitor discharge:
1. Switch circuit-breaker on.
2. Switch supply voltage off (m.c.b.).
3. Switch circuit-breaker by pressing push-buttons
3 and 4 with cycle: OFF/ON/OFF.
The "Ready" lamp will go out when this
switching cycle is completed, i.e., the switch is
no longer ready for switching operations.
4. After the following waiting times the storage
capacitor will have discharged down to lower
than 15 V:
– after approx. 4 minutes for breaking currents
up to 25 kA
– after approx. 8 minutes for breaking currents
of 31.5 kA and above.
Where appropriate in individual cases, further
information can be found in the technical
documentation appurtenant to the switchgear
system (e.g. agreed special operating conditions)
in addition to this operating manual.
14
secured to prevent
the operating mechanism,
7.2

Inspection and functional testing

7.2.1 Circuit-breaker in general

• Under normal operating conditions, inspection
within the stated number of operating cycles is
not necessary.
• Inspection may be necessary under exceptional
operating conditions (including adverse climatic
conditions) and/or particular environmental
stresses (e.g. serious contamination and ag-
gressive air).
• The inspection primarily comprises visual exa-
mination for contamination, corrosion, moisture
and discharge phenomena on the high voltage
side.
If an irregular condition is found, appropriate
maintenance work is to be initiated.
• No external discharge may occur on the
surfaces of equipment at operating voltage. This
can, for example, be detected by characteristic
noises, a clearly perceptible smell of ozone, or
re-
visible glowing in the dark.
• Visual checking of the isolating contact system.
We recommend to turn alternately the contact
system in order to clean the inner contact points
of the contact system.
The contact points should be cleaned if signs of
unperminable overheating (discoloured surface)
are visible (see section Repair)
• If irregular conditions are detected, then
corresponding repair measures should be
initiated.

7.2.2 Magnetic actuator operating mechanism

(Figures 9/19 and 9/28)
A first functional test of the operating mechanism is
to be performed:
• after the stated number of operating cycles, or
• during maintenance work as described in
section 7.2.1.
Before the functional test, open the circuit-breaker
and
• move it into the test position (withdrawable
breaker) or
• isolate and secure the working area in
accordance with the Safety Regulations to DIN
VDE / IEC (with stationary mounted breakers).
• Observe the procedure for capacitor discharge
as set down in section 7.1.
• Perform visual examination of the condition
(removing front plate 1.1), e.g.:
– the lubrication at the rotary bearings,
– the operating cycle counter,
– the sensor mounting,
– the position indicator.