ABB RET650 Technical Manual page 336

Section 12
Control
330
When invalid data such as intermediate position, loss of a control IED, or input board
error are used as conditions for the interlocking condition in a bay, a release for
execution of the function will not be given.
On the local HMI an override function exists, which can be used to bypass the
interlocking function in cases where not all the data required for the condition is valid.
For all interlocking modules these general rules apply:
• The interlocking conditions for opening or closing of disconnectors and earthing
switches are always identical.
• Earthing switches on the line feeder end, for example, rapid earthing switches, are
normally interlocked only with reference to the conditions in the bay where they
are located, not with reference to switches on the other side of the line. So a line
voltage indication may be included into line interlocking modules. If there is no
line voltage supervision within the bay, then the appropriate inputs must be set to
no voltage, and the operator must consider this when operating.
• Earthing switches can only be operated on isolated sections for example, without
load/voltage. Circuit breaker contacts cannot be used to isolate a section, that is,
the status of the circuit breaker is irrelevant as far as the earthing switch operation
is concerned.
• Disconnectors cannot break power current or connect different voltage systems.
Disconnectors in series with a circuit breaker can only be operated if the circuit
breaker is open, or if the disconnectors operate in parallel with other closed
connections. Other disconnectors can be operated if one side is completely
isolated, or if the disconnectors operate in parallel to other closed connections, or
if they are earthed on both sides.
• Circuit breaker closing is only interlocked against running disconnectors in its
bay or additionally in a transformer bay against the disconnectors and earthing
switch on the other side of the transformer, if there is no disconnector between CB
and transformer.
• Circuit breaker opening is only interlocked in a bus-coupler bay, if a bus bar
transfer is in progress.
To make the implementation of the interlocking function easier, a number of
standardized and tested software interlocking modules containing logic for the
interlocking conditions are available:
• Line for double and transfer busbars, ABC_LINE
• Bus for double and transfer busbars, ABC_BC
• Transformer bay for double busbars, AB_TRAFO
• Bus-section breaker for double busbars, A1A2_BS
• Bus-section disconnector for double busbars, A1A2_DC
• Busbar earthing switch, BB_ES
• Double CB Bay, DB_BUS_A, DB_LINE, DB_BUS_B
• 1 1/2-CB diameter, BH_LINE_A, BH_CONN, BH_LINE_B
The interlocking conditions can be altered, to meet the customer specific
requirements, by adding configurable logic by means of the graphical configuration
1MRK 504 135-UEN A
Technical manual