Kraus & Naimer, an Austrian manufacturer with more than a century of experience, is a global reference for cam-operated switches and switch disconnectors. Built to IEC 60947-3 and VDE 0660, the "Blue Line" programme covers continuous currents from 10 A up to 2400 A and serves industrial control, motor switching, power distribution and personnel safety isolation. This guide explains how to choose the right switch family and the parameters that matter most.

1. Choose the right product family

C series — classic cam switches

The C series is the original Kraus & Naimer cam switch. With easily accessible fixing-screw terminals it suits most cam-switch applications: general on/off and change-over switching, main-circuit isolation, multi-position control and equipment isolation during maintenance. Typical thermal-current range 10 A–315 A (higher ratings available across the programme).

CA / CAD series — finger-safe control and load switches (10 A–32 A)

CA and CAD switches add finger-protected terminals to EN 50274 / VDE 0660 part 514, making them ideal for control, instrumentation and motor circuits. Captive plus-minus terminal screws and integrated screwdriver guides speed up wiring. The CA4-1 variant offers gold-plated contacts for reliable low-level signal switching in humid, dusty or corrosive environments. CAD types ship with open terminals protected against accidental finger contact.

KG series — switch disconnectors

The KG range provides a clearly visible break and high short-circuit withstand capacity, making it the first choice for equipment isolation and motor switching (AC-21A resistive / AC-23A motor loads). Available in 3- and 4-pole versions with panel (FT), base (VE) or DIN-rail mounting, and optional door interlock and lockable handle (e.g. KG32B) to prevent inadvertent re-closing.

L series — off-load switches

L-series switches are continuous-current rated for off-load switching of resistive or low-inductive loads and are available in high current ratings (e.g. L350–L2000).

2. Key selection parameters

• Rated current and voltage: select by thermal current and AC-3 motor rating (kW). For example KG41 suits about 15 kW direct-on-line motor starting, while KG100 covers about 37 kW.

• Poles and positions: define the number of poles and switching positions, then choose the matching cam programme (e.g. A214, A730) so the contact make/break sequence matches your control logic.

• Terminals and wiring direction: finger-safe versus open box terminals; horizontal or vertical wiring depending on panel versus base mounting.

• Mounting: panel (2/4-hole), base, or DIN rail — match the available space in the enclosure.

• Environment: standard IP40; specify a CL-type enclosure to reach IP66 for wet, dusty or outdoor use.

• Accessories: auxiliary contacts for status feedback, door couplings and lockable handles for safety.

3. Typical applications

Motor start/stop and forward-reverse control, speed and tapping selection, mains and emergency isolation, instrumentation and signal switching, and switching of resistive or low-inductive loads in distribution boards.

As a long-term Kraus & Naimer supplier, EFFSEN stocks C, CA, CAD, KG and L series switches and provides selection support, fast delivery and global shipping for industrial automation projects.