Maintenance
9229 9947 176 0C
49
2013-03-28
Maintenance
Maintenance and servicing
To maintain reliability during the entire operating time and to ensure the operating
cycle numbers, depending on
• the type of vacuum circuit-breaker (see “Technical data” on page 31)
• the operating conditions see “Ambient conditions” on page 32),
• the number of mechanical and electrical operating cycles,
• and the operating time,
regular maintenance work must be performed according to the following
maintenance plan.
This is especially the case for the vacuum circuit-breaker
• with instantaneous release 3AX601 for traction power supply with 16.7 Hz for
compliance with the short break-times and
• with two vacuum interrupters arranged one over the other to ensure sufficient
synchronism of the two vacuum interrupters.
DANGER
High-voltage – danger to life
Touching live parts is fatal or causes serious physical injury.
Before beginning maintenance work, note the five safety rules for high-voltage
equipment specified in EN 50110-1, namely:
• Isolate from the power supply*
)
• Secure against reclosing
• Verify safe isolation from the power supply
• Earth and short-circuit
• Cover or cordon off neighboring live parts
*
)
On the vacuum circuit-breaker, actuate the OPEN, CLOSED and OPEN
pushbuttons manually one after the other. This ensures that the vacuum circuit-
breaker is open and the closing spring is relaxed.
Note
The vacuum circuit-breaker should be taken out of the switch cabinet or
switchgear for servicing.
Note
Applies to the 3AH4756 and 3AH4757 vacuum circuit-breakers with grading
capacitors:
If the vacuum circuit-breaker is taken from the switchgear, any residual charge of
the capacitors, e.g. due to brief closing of the vacuum circuit-breaker, should be
diverted. However, due to the low capacity, direct contact is not dangerous.
