3 Description
5.00 Bellows
5.10 Microswitch
5.20 Housing
5.30
Circuit-breaker gas compartment
5.40
Reference gas compartment
Fig. 22
Schematic diagram of the density monitor (under
working pressure)
3.8.3 Lockouts
The individual functions are explained in the order of their appearance in the circuit diagram.
A General lockout SF
6
prevents any switching of the circuit-breaker if the SF
6
pressure is too low.
The closing lockout prevents the circuit-breaker from being switched on while the closing spring is being charged.
The anti-pumping device of the circuit-breaker pole ensures that it is not repeatedly opened and closed in the
event of simultaneous CLOSE and OPEN commands.
The swich S4 is for acknowledgement of enforced triple-pole operation.
3.8.4 Motor
Control
The motor charges the closing spring and is controlled by a limit switch.
3.8.5 Anti-Condensation
Heaters
To protect sensitive components in the operating mechanism cubicles and in the control cubicle from condensed
water during rapid temperature changes, the units are always fitted with heating resistors. As condensation can
occur at any ambient temperature, these resistors must always be in continuous operation.
3.8.6 Signals
Signals are information on the condition of the circuit-breaker.
36