© Bernd Schifferdecker

A quantum of voltage

Extra-low voltage and sepa­rated extra-low voltage are not the same. Because the voltage applied to indus­trial drives for safety reasons is not a general issue but always a specific one. Philipp Rauch, Market Manager OEM Indus­trial Drive Tech­nology at ebm-papst in St. Georgen, explains why.

Extra-low voltage is a low voltage range and is defined as a maximum 120 V DC voltage or a maximum of 50 V AC. Although extra-low voltage is not harm­less for humans and animals, it is defi­nitely not life-threat­ening. And extra-low voltage in the surrounding area can also be useful for sensi­tive devices. 24 or 48 V DC are stan­dard for indus­trial drives from ebm-papst. Of course, this does not mean that the motors have to be connected to exactly this voltage. In fact, recti­fiers and trans­formers in power supply units ensure safety and customers can use supply connec­tions or batteries in most cases.

A surgeon with calm hands

But what voltage is now consid­ered a sepa­rated extra-low voltage? There are no general answers to this ques­tion, only specific answers. Because there is no classic defi­n­i­tion for sepa­rated extra-low voltage, just the idea that the voltage must be completely safe, which simply depends on the appli­ca­tion in ques­tion. An elec­tri­cally oper­ated oper­ating table, for example, has to fulfill partic­u­larly high require­ments to protect the patient. Although 120 V DC voltage is consid­ered to be (almost harm­less) low voltage on paper, even small muscle reflexes caused by elec­tricity could be fatal for patients or surgeons. The safety concept and device design in place are also deci­sive to choosing the right voltage: with a suit­able isola­tion concept, the drives from the modular drive system from ebm-papst suit any appli­ca­tion.

Perfect for self-driving systems

Extra-low voltage is not asso­ci­ated with a reduc­tion in perfor­mance, as you might think. ebm-papst drives with extra-low voltage are used, among other things, to drive auto­mated guided vehi­cles (AGV) in intral­o­gis­tics and are still powerful, effi­cient and compact. With AGVs, customers do not need to make any compro­mises on perfor­mance and never­the­less can be sure that the vehi­cles pose no risk of elec­tric shock.

Less risk = less effort

If customers can easily rely on extra-low voltage drives for their appli­ca­tions, they can also benefit in other ways that are not obvious at first glance: for example, personnel without qual­i­fi­ca­tions in dealing with low voltage may also carry out commis­sioning if this is permitted by the safety and risk assess­ment. And more simple system and factory concepts are possible for assembly robots, for example. There­fore, extra-low voltage proves itself several times over, and the right sepa­rated extra-low voltage even more so. 

Required fields: Comment, Name & Mail (Mail will not be published). Please also take note of our Privacy protection.