33
Instruction manual
| Types SDV-R and SDV-R-AR distribution circuit breakers
Item
Description
1.0
Magnet core
3.0
Housing
5.0
Mounting holes
7.0
Magnet coil
9.0
Magnet armature
11.0
Tension spring
13.0
Adjusting screw
(factory set) for 11.0
15.0
Tripping pin
21.0
Locking pin
23.0
Striker pin
25.0
Latch
27.0
Spring
31.0
Striker-pin spring
33.0
Terminal block
Item
Description
21.0
Locking pin
23.0
Striker pin
25.0
Latch
27.0
Spring
29.0
Locked/unlocked selection screw
Indirect releases - secondary shunt
release (auxiliary trip) (52T1) or
undervoltage
The indirect release provides for the
conversion of modest control signals into
powerful mechanical-energy impulses. It is
primarily used to open medium-voltage
circuit breakers while functioning as a
secondary shunt-release (dual trip) or
undervoltage device.
These releases are mechanical energy-
storage devices. Their internal springs are
charged as a consequence of the circuit
breaker mechanism operation. This energy
is released upon application or removal (as
appropriate) of applicable control voltages
(refer to Figure 19: Construction of
secondary shunt release (shown charged),
Figure 20: Latch details (shown charged)
and Figure 21: Undervoltage lock/operate
selection on page 34. The secondary shunt-
release and undervoltage release mounts to
the immediate left of the trip coil (80.0).
Secondary shunt releases (52T1)
Refer to Figure 19: Construction of
secondary shunt release (shown charged). A
secondary shunt-release (extra-trip coil)
(3AX1101) is used for electrical opening of
the circuit breaker by protective relays or
manual control devices when more than
one trip coil is required. The second trip coil
is generally connected to a separate
auxiliary supply (dc or ac) from the control
supply used for the normal trip coil. An
alternate configuration is available where an
additional coil identical to the primary coil is
used for three-cycle applications.
Undervoltage releases
Refer to Figure 20: Latch details (shown
charged) and Figure 21: Undervoltage lock/
operate selection on page 34. The
undervoltage release (3AX1103) is used for
continuous monitoring of the tripping
supply voltage. If this supply voltage falls
excessively, the undervoltage release will
provide for automatic tripping of the circuit
breaker. The undervoltage device may be
used for manual or relay tripping by
employing a contact in series with
undervoltage device holding coil. Relay
tripping may also be achieved by employing
a normally open contact in parallel with the
holding coil.
Figure 19: Construction of secondary shunt release (shown charged)
23.0
13.0
9.0
15.0
5.0
3.0
11.0
21.0
25.0 27.0
7.0
31.0
33.0
1.0
Figure 20: Latch details (shown charged)
23.0
25.0
29.0
21.0
27.0
Locked/unlocked selection screw (undervoltage release only)
If this scheme is used, a resistor must be
provided to limit current when the normally
open contact is closed. Secondary shunt and
undervoltage releases are available for all
standard ANSI/IEEE control voltages.