Interlock/Protection Against Erroneous Operation; Panel Internal Interlocking; Door Interlocking; Interlocks Between Panels - ABB UniGear ZS1 Instruction Manual

3.4 Interlock/protection against erroneous operation

14
3.4.1 Panel internal interlocking (Figure 2)
To prevent hazardous situations and erroneous operation, there is a series of interlocks to protect both
personnel and equipment:
• The withdrawable part can only be moved from the test/disconnected position (and back) when the
circuit-breaker and earthing switch are off (i.e. the switch must be off beforehand.) In the
intermediate position, the switch is mechanically interlocked. When the circuit-breakers have an
electrical release, the interlock is also electrical;
• The circuit-breaker can only be switched on when the withdrawable part is in the test or service
position. In the intermediate position, the switch is mechanically interlocked. When the circuit-
breakers have an electrical release, the interlock is also electrical;
• In panels with digital control technology, prevention of malfunction of the switch can also be achieved
by means of the control terminal (i.e. REF542 plus );
• In the service or test positions, the circuit-breaker can only be switched off manually when no control
voltage is applied and it cannot be closed (electromechanical interlock);
• Connecting and disconnecting the control wiring plug 10.2 (figure 5) is only possible in the test/
disconnected position of the withdrawable part;
• The earthing switch 6 can only be switched on if the withdrawable part is in the test/disconnected
position or outside of the panel (mechanical interlock ¹);
• If the earthing switch is on, the withdrawable part cannot be moved from the test/disconnected
position to the service position (mechanical interlock);
• Optionally there can be interlocking on shutters to prevent opening them manually. If it is applied
then a shutter device needs to be ordered;
• Details of other possible interlocks, e.g. in connection with a locking magnet on the withdrawable
part and/or earthing switch drive, can be obtained from the relevant order documents.
3.4.2 Door interlocking (Figures 13 to 20)
The panels can be equipped with the following interlocks (all optional):
• The apparatus (circuit-breaker or contactor) cannot be racked-in if the apparatus compartment door
is open (figure 13, 14). ³);
• The apparatus compartment door cannot be opened if the apparatus (circuit-breaker or contactor)
is in service or in an undefined position (figure 15, 16);
• The earthing switch cannot be operated if the cable compartment door is open (figure 17, 18);
• The cable compartment door cannot be opened if the earthing switch is open (figure 19, 20).
Warning
It is important that when the front doors (circuit-breaker and cable) are supplied with
screws, these screws are all fixed properly in order to guarantee the interlocks and the
safety of the personnel in case of internal arc.

3.4.3 Interlocks between panels

• The busbar earthing switch can only be closed when all the withdrawable parts in the relative busbar
section are in the test/disconnected position (electromechanical interlock ²);
• When the busbar earthing switch is closed, the withdrawable parts in the earthed busbar section
cannot be moved from the test/disconnected position to the service position (electromechanical
interlock ²).
3.4.4 Locking devices (Figure 2)
• The shutters 12.1/12.2 can be secured independently of each other with padlocks when the
withdrawable circuit-breaker part has been removed;
• Access to the operating-shaft 14.1 of the earthing switch can be restricted with a padlock;
• Access to the circuit-breaker racking slot can be restricted with a padlock;
• Access to the circuit-breaker compartment and the cable compartment can be restricted with a
padlock.
1) In the case of a motor operator, the mechanical interlock or the locking magnet is replaced by an electrical interlock of the
earthing switch. The manual emergency switch is not locked!
2) The locking magnet is not installed in the case of a motor operator; busbar earthing switches or the withdrawable parts are
electrically locked. The manual emergency switch is not locked!
3) This interlock is not available for motor-operated withdrawable apparatus as a mechanical device.