Structure; Structure Of The Operating Mechanism; Structure Of The Control Module; Storage Capacitor - ABB VM1 Instruction Manual

2

Structure

2.1

Structure of the operating mechanism

(Figures 9/11 to 9/14 and 9/26)
The operating mechanism is of the magnetic type. It funda-
mentally consists of the magnetic actuator 10, the control
module 27 with sensor systems, the storage capacitor(s)
26 and the linkages which transmit the force to the breaker
poles.
In addition, there are supplementary components for emer-
gency manual opening and the controls located on the front
of the enclosure.
The actuator 10 acts on the three breaker poles via lever shaft
18. The storage capacitor 26 provides the necessary actuat-
ing energy on demand.
The mechanical switch positions of the circuit-breaker are
detected by two sensors 15 and 16 directly at lever shaft 18.
There are rating plates 7 with the main data of the switching
device on front plate 1.1, and at the left side in the mecha-
nism enclosure.
The basic version of the magnetic actuator mechanism is fit-
ted with the following controls and instruments (figure 9/17):
- ON push-button 3
- OFF push-button 4
- Emergency manual OFF 8
- Mechanical position indicator 6
- Mechanical operating cycle counter 5
- Signal lamp for switching readiness 2
("READY" lamp).
The following may also be installed:
- Five-pole auxiliary switches for switch position signal:
-BB1 and -BB3.
2.1.1

Structure of the control module

(Figures 9/14 and 9/16a)
Control module ED 2.0 produces a voltage of 80 V from any
supply voltage within the input voltage range, with which the
storage capacitor(s) is/are charged. This is also used to gen-
erate a voltage of 18 V to supply the breaker controller.
The circuit-breaker controller consists of:
- a microprocessor,
- electronic optocouplers for input,
- relays for output,
- power electronics to control the actuator coils.
2.1.2

Storage capacitor

(Figures 9/14, 9/16b and 9/26)
The energy for operation of the circuit-breaker is stored elec-
trically in a capacitor. Circuit-breakers for breaking currents of
31.5 kA and above are fitted with two capacitors. The capaci-
tors are designed in such a way that the energy for an
OFF-ON-OFF operating cycle is provided without recharging.
The energy stored by the capacitor is permanently monitored.
This is achieved by measuring the capacitor voltage.
The „READY" lamp indicates that supply voltage is applied
and the circuit-breaker is ready for the im pending switching
operation (see also sections 3.1.5 and 6.2).
The energy stored in the capacitors is one criterion for illumi-
nation of the "READY" lamp:
- Case 1: Breaker in the OFF position.
- The energy available is sufficient for an ON and an OFF
switching operation.
- Case 2: Breaker in the ON position.
- The energy available is sufficient for an OFF switching
operation.
- The energy available is sufficient for an OFF switching
operation in the first 60 or 120 seconds (from 31.5 kA)
after failure of the auxiliary power supply (see also sec-
tion 6.5).
If the energy stored is not sufficient, the "NOT READY"
contact is closed, indicating that the switch is not ready for
operation.
2.1.3

Sensor system

(Figures 9/13 and 9/14)
The systematic use of sensors permits control of the circuit-
breaker without auxiliary switches.
Two inductive proximity switches 15 and 16 are used to
detect the mechanical limit positions, which also provide for
self-monitoring of the system.
2.2

Structure of the breaker poles

(Figures 9/7, 9/9 and 9/12)
The poles in column design are mounted on the bracket-
shaped rear part of mechanism enclosure 1. The live parts of
the breaker poles are enclosed in cast resin and protected
from impacts and other external influences.
With the breaker closed, the current path leads from the
upper breaker terminal 25 to the fixed contact 24.2 in the
vacuum interrupter 24, then via the moving contact 24.1 and
the flexible connector 21 to the lower breaker terminal 22.
The switching motions are effected by means of the insulated
link rod 19 with internal contact force springs 20.
Instruction manual 504/05 | VM1 Vacuum circuit-breaker 7