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Switch-disconnector functions
Compact NSX100 to 630 NA switch-
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and withdrawable versions. They use the
same accessories and offer the same
connection possibilities as the circuit-
breaker versions.
They may be interlocked with another
Compact switch-disconnector or circuit
breaker to forma source-changeover system.
Suitability for isolation with positive contact
indication
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IEC 60947-3. The corresponding conformity tests guarantee:
the mechanical reliability of the position indication, i.e. the O (OFF) position
b
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the required distance between contacts is provided
v
padlocks may not be installed unless the contacts are open
v
the absence of leakage currents
b
overvoltage withstand capacity between upstream and downstream connections.
b
Installation of a rotary handle or a motor mechanism does not alter the reliability of
the position-indication system.
Emergency-off function
ACompact NSX NA is combined with an MN or MX release connected to an
emergency-off button. In an emergency, an operator at a remote location can
interrupt the circuit at rated load to isolate the entire switchboard and the
downstream loads.
Motor mechanism
Compact NSX NA devices equipped with a motor mechanism module enable remote
closing and opening. This function may be combined with the emergency-off
function. In this case, the emergency off function is combined with a closing lock-out
that must be intentionally reset (electrical diagram with closing lock-out).
Earth-leakage protection
A Vigi module may be added to a switch-disconnector to monitor all leakage currents
in the outgoing circuits of the switchboard on which the switch-disconnector is
installed. When the Vigi module detects an earth-leakage current, the switch-
disconnector interrupts the load current. This function may be combined with the
motor mechanism and the emergency-off function using an MN or MX release.
Switch-disconnector protection
The switch-disconnector can make and break its rated current. For an overload or a
short-circuit, it must be protected by an upstream device, in compliance with
installation standards.
The circuit-breaker/switch-disconnector coordination tables determine the required
upstream circuit breaker. However, due to their high-set magnetic release, Compact
NSX100 to 630 A switch-disconnectors are self-protected.
Switch-disconnector utilisation category
Depending on the rated operational current and the mechanical durability (A for
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utilisation categories as shown in the table below. Compact NSX NA switch-
disconnectors comply with utilisation categories AC22A or AC23A.
PB103199-28
Compact NSX switch-disconnector.
PB103372-34
Compact NSX switch-disconnector
equipped with a motor mechanism module.
PB103629-31
Compact NSX switch-disconnector
equipped with a Vigi module.
Utilisation category
Typical applications
Infrequent
operation
Frequent
operation
AC-21A
AC-21B
Resistive loads including moderate overloads (cos
K
=
0.95)
AC-22A
AC-22B
Mixed resistive and inductive loads including moderate
overloads (cos
K
= 0.65)
AC-23A
AC-23B
Motor loads or other highly inductive loads (cos
K
= 0.45
or 0.35)
559E1700.indd
version: 1.0