Switch Disconnectors

Switch Disconnectors

3NJ62 In-Line Switch Disconnectors with Fuses up to 630 A

Introduction

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Siemens LV 10 · 2014

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Benefits

Key advantages for switchgear manufacturers

due to the following:

• Compact, modular design

• Simple and efficient mounting due to incoming plug-in contact

• High packing density in the field

• Cable connection with cable clamps or cable lugs

• Can be mounted in different control cabinet depths

• Comprehensive range of accessories

The advantages for users are:

• Conversion, retrofitting and replacement

without switching off the switchgear

• Dead-state fuse replacement

• Maintenance-free

• High personal safety

• Operating handle can be locked in OFF position

• Clear and unambiguous switch position indicator

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Application

The plug-in 3NJ6 switch disconnectors with fuses are installed

in low-voltage distribution boards where a minimum amount of

space is available for a maximum number of cable ducts to the

power distribution. They can be easily fitted in all common con-

trol cabinets (minimum depth: 400 mm).

The plug-in 3NJ62 switch disconnectors with fuses are available

for rated uninterrupted currents from 160 A to 630 A.

LV HRC fuse links according to IEC 60269-1/EN 60269-1 (sizes

NH 00 to NH 3) or BS fuse links according to BS 88 provide over-

load and short-circuit protection up to 690 V AC.

The switch disconnectors can be retrofitted at any time with aux-

iliary switches, an ammeter (48 mm x 48 mm) and current trans-

formers, with no extra space required. For installation in control

cabinets of > 400 mm depth, the mounting depth of the discon-

nectors can be increased by 200 mm using a contact extension.

Further installation accessories, such as guide rails and blank-

ing covers, complete the product range.

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Function

Fuse monitoring

Fuse monitoring is used to detect, indicate and report faults.

The electronic fuse monitoring devices are available in

2 versions.

EFM 10 electronic fuse monitoring devices:

• For use up to 690 V AC

• Operational voltage < 20 V

• Display: ready-to-run

• Individual fault display per phase

• 1 CO contact as centralized fault signaling unit

EFM 20/25 electronic fuse monitoring and line monitoring

devices:

• EFM 20 for use up to 690 V AC, EFM 25 for use up to 440 V DC

• Operational voltage < 13 V (EFM 20) < 20 V (EFM 25)

• Test function

• Closed-circuit principle or open-circuit principle

• 2 CO contacts as centralized fault signaling unit incl. line

monitoring functions with phase failure detection (EFM 20),

undervoltage/overvoltage detection

EFM 10 electronic fuse monitoring device

EFM 20/25 electronic fuse monitoring device