L3447
Emax DC
27/108
Doc. No.
Model
Apparatus
Scale
Page No.
1SDH000635R0002
L3728
Table of feasible mechanical interlocks between two or three circuit-breakers
Type of
Number of
Type of circuit-breaker
Possible interlocks
interlocks
circuit-breakers
A
TWO
a normal power supply unit
the first circuit-breaker can be closed only if
and an emergency unit
the second (emergency) breaker is open
B
THREE
two normal power supply units and
the first and third circuit-breakers can be
an emergency unit
closed only if the second (emergency)
breaker is open. The latter can be closed
only if the first and third are open
C
THREE
a unit of 2 supplies and a bus-tie.
one or two circuit-breakers out of three can
The two half-busbars can be supplied
be closed at the same time
by a single transformer (bus-tie closed)
or simultaneously by both
(bus-tie open)
D
THREE
a unit of 3 supplies / a single
only one of the three circuit-breakers can
closed circuit-breaker. Three supplies be closed
(generators or transformers) on the same
busbar for which parallel operation is
not allowed
10.3 Spare parts
The spare parts available are:
– Shields and front escutcheon plate
– Opening solenoid for the PR122/DC-PR123/DC overcurrent release
– Arcing chamber
– Closing springs
– Clamp-type isolating contact for fixed part of the withdrawable circuit-breaker
– Sliding earth contact (for withdrawable version)
– Fixed part shutters
– Operating mechanism
– Transparent protection for PR122/DC and PR123/DC releases
– SACE PR030/B power supply unit
– Tool case
– Front escutcheon plate for Ronis-type key lock
For further details, ask for the ABB SACE spare parts catalogue.
