Safe disconnect in accordance with IEC 62626-1

Jon Lawson

8146/5-V37 and 8150/5-V37 safety switches (load disconnect switches) from R. STAHL give users a wide range of products that comply with IEC/EN 62626-1, class 1.

Specifically applying to the forced electrical disconnection of safety switches, this standard has come into effect in December 2014. It stipulates requirements for encapsulated load disconnect switches up to 1,000 V AC that are used to disconnect electrical equipment, such as machines and equipment, for the purpose of maintenance and cleaning.

The new requirements go far beyond those in IEC/EN 60947-3. The IEC/EN 62626-1 distinguishes between switching devices for general use (class 0) and those for rough, heavy-duty conditions (class 1). It is advisable to use class 1 switching devices in hazardous areas. Series 8146/5-V37 and 8150/5-V37 switches are built into robust and corrosion-resistant enclosures made of GRP or stainless steel. They come with flameproof-enclosed 3- or 6-pole switch contacts and are certified for use in zones 1 and 2, 21 and 22.

The product range includes switchgear for rated operational currents between 10 A and 180 A and an operating voltage between 230 V and 690 V. Their motor switching capacity is equivalent to AC 3 and AC 23 according to IEC/EN 60947-3. A 20 ms leading auxiliary contact ensures a motor switch-off even when used with frequency converters.

The integration of the auxiliary contact into the load switch allows for operating only one rotary actuator, resulting in improved usability. The load disconnect switches provide IP66 ingress protection and are designed for a temperature range of -40 °C to +70 °C. In addition to the forced opening of the main contacts, easy handling and a special safety mechanism ensure maximum operating safety: the cover is locked in 'off' position, the switch handle can be locked with three padlocks. 

Machine drives in hazardous areas can therefore be stopped quickly and safely to facilitate cleaning a plant, repair operations or other service work, without needing a trained electrician.