Safety relay PNOZ s50 – Safe, contactless control of two brakes

Pilz: The new safety relay PNOZ s50 can safely control two powerful brakes simultaneously without the use of contacts. As such it provides the required level of safety, particularly in the field of vertical axes: on loading and unloading gantries, machine tools, lifting devices and in stage technology, for example, a suspended load’s own weight may be enough to allow the axis to fall unintentionally. Thanks to the reduced cycle times, the safety relay also increases the plants' energy efficiency significantly.

The safety relay PNOZ s50 with emergency stop function is designed to control holding brakes or safety brakes in the 24/48 Volt DC range on vertical axes up to PL e of EN ISO 13849-1 or SIL CL 3 of EN/IEC 62061. The special feature about this new development on the market is that two brakes, even brakes from different manufacturers, can be controlled simultaneously using one safety relay. Due to the high output current of 3.5 ampere, PNOZ s50 can control powerful brakes for heavy loads; if necessary up to peak currents of 6.5 ampere.

The safety relay PNOZ s50 offers a high level of safety due to fast shutdown of the power circuits. The alternative option of a slow shutdown enables low-noise switching of the brakes. Four safety-related and two standard inputs are available to activate the functions.

High energy efficiency due to reduced cycle times

To improve the cycle times, and thus the plant’s energy efficiency, Pilz uses pulse width modulation to reduce the voltage. Contactless and therefore non-wearing technology in the 24/48 Volt DC range is also new. It reduces the reaction time in conjunction with the brake, significantly improving protection for operating personnel.  

Depending on the safety requirement, PNOZ s50 can also be combined with the safe motion solution PMCprotego DS from Pilz, in which case it also provides a safe brake test (SBT). Just like other developments in the PNOZsigma product range, PNOZ s50 has a rotary knob for easy navigation through the menu and for setting the required parameters. This saves time during setup, as neither a PC nor software is required.

Vertical axes present a safety challenge

Failure of the braking device due to wear and tear plus failure of the energy supply are two of the main reasons for suspended loads falling or crashing in an uncontrolled manner. The safety relay PNOZ s50 makes an important contribution towards the management of risks on vertical axes. Typical application areas for vertical axes are loading and unloading gantries, machine tools, lifting devices and stage technology.