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PART C Operating Mechanism working principle & maintenance
OPERATING MECHANISM
1.0 Spring charged mechanism
1.1 General
The operating mechanism has a spring charging
device, which can be operated by motor or
manually. The operating device has helical
tension spring for closing and opening. The
opening spring is charged automatically when
the breaker is closed.
A closed breaker with charged closing spring can
thus
be
operated
OPEN - CLOSE - OPEN
without
intermediate
charging, and the breaker can, therefore, be
used for auto re-closing duty cycle.
An indication shows whether the closed spring is
charged or not, and the number of opening
operations are recorded by the counter.
The motor can be supplied via station battery, a
network or via transformer with a limit load of at
least 500 VA.The motor starts after each closing
operation and charges the closing springs within
15 seconds.
4
6
5
1
8
motorized
or manual
Fig. A
1.2 Construction
The construction of the operating mechanism is
shown in Fig A.
Major components of ESH mechanism are:
1. Closing Spring
2. Tripping Spring
3. Geared-Motor
4. Push Button Assembly
5. Closing Coil
6. Tripping Coil.
7. Motor cut-off switch.
8. Auxiliary switch.
9. Spring Charged indication
10. Breaker ON/OFF indications
11. Bottom Shaft (Charging Shaft)
12. Top Shaft (Power Shaft)
10
11
12
34
9
7
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