Siemens LV 10 · 2004 7/17
SENTRIC NP Fuse Switch Disconnectors
General data
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Area of application
SENTRIC NP fuse switch disconnectors are switching devices
for the occasional manual connection and disconnection of
loads and distribution boards. They are designed to connect the
specified rated nominal current (including a specified overload),
to carry it and to disconnect it.
SENTRIC NP fuse switch disconnectors are used to isolate all
poles of downstream electrical loads safely under load
conditions.
The SENTRIC NP fuse switch disconnectors are ideally suited for
surface mounting or installation in distribution boards (e.g.
ALPHA, SIKUS), meter cabinets (e.g. ALPHA 400-ZS), and
molded-plastic distribution panels e.g. SENTRIC HP.
The ability to mount these devices onto many different busbar
systems supports a wide range of applications in the
construction of control cabinets and control systems.
SENTRIC NP size NH 0002) and NH 00 can be snapped onto
35mm standard mounting rails and are optimized for use with
other switching devices, for example, in capacitor units for the
purpose of reactive-power compensation.
SENTRIC NP fuse switch disconnectors are used in combination
with semiconductor protection fuses (e.g. SITOR) for the
effective protection of frequency converters and soft starters.
SENTRIC NP fuse switch disconnectors
3NP40 10 3NP40 70 3NP52 with open fuse carrier
The SENTRICNP fuse switch disconnectors are suitable for use
in any climate and comply with the specifications of
IEC60947-1, IEC 60947-3 and DIN VDE 0660 Par t 107.
The 3NP401 and 3NP40 7 variants are available tin-plated for
use in extremely sulphurous atmospheres (available on request).
In addition, the SENTRIC 3NP5 series of fuse switch disconnec-
tors complies with the requirements of BS 5419 and is also ap-
proved for marine applications.1)
All SENTRIC NP fuse switch connectors are either sealable as
standard or using accessories.
1)Use only approved fuse links.
2)Corresponds to fuse sizes NH 000 (NH 00C) or NH 00
with smaller dimensions; maximum width 21 mm according to
IEC 60269-2-1 and DIN VDE 43620.
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Design
The SENTRIC NP fuse switch disconnectors comprise a fuse
base and a removable fuse carrier with an inspection and mea-
suring function window.
Lyre-shaped contacts, arc chambers and connection pieces are
integrated in the fuse base. The fuse links or isolating links are
stored in the fuse carrier.
The fuse links can be replaced or changed without the need for
any tools.
The three conducting paths in the fuse base as well as the fuse
links in the fuse carrier are separated by partition walls that over-
lap when the device is opened and closed.
This strong self-protection is known as "full compartmentaliza-
tion" and effectively and reliably prevents inter-phase arcing.
LV HRC fuses of sizes NH 000 to NH 3 according to
IEC60269-2-1 and DIN VDE 43620 are used in the SENTRIC NP
fuse switch disconnectors. Furthermore, SITOR semiconductor
protection fuses are also used.
For further details, see the operating instructions for the
SENTRIC NP fuse switch disconnectors.
Auxiliary switches
The SENTRIC NP fuse switch disconnectors can be retrofitted
with auxiliary switches for signaling the switch position of the
fuse carrier.
One contact element (1 CO) can be mounted on size NH 000 of
the SENTRIC 3NP4 fuse switch disconnector and two contact el-
ements (1 CO) can be mounted on sizes NH 00 to NH 3.
Further variants and accessories for the SENTRICNP fuse
switch disconnectors as well as the complete SENTRICNP se-
ries in industry-compatible design for increased technical re-
quirements can be found in Catalog LV 30.