Title: 36 Siemens GDB181-MO.pdf.pdf
AC 24 V systems should always be earthed if this does not contradict the manufacturer’s specification. To avoid earth loops, systems with PELV may only be earthed at one point of the system, normally by the transformer, unless otherwise specified.VAV Compact Controller Modbus RTUA6V10631862_en--_d 2019-09-13Device safetyElectrical parallel connectionKNX bus poweringNoteWarning,maintenanceSiemens Smart InfrastructureAC 24 VThe operating voltage must comply with the requirements for SELV or PELV:The operating voltage must comply with the requirements for SELV or PELV:Permissible deviation of AC 24 V nominal voltage at the actuators: +/–20 %Permissible deviation of AC 24 V nominal voltage at the actuators: +/–20 %Specification on AC 24 V transformersSafety isolating transformers as per EN 61558, with double insulation, designed for 100 % on time to power SELV or PELV circuitsDetermine the transformer’s output by adding up the power consumption in VA of all actuators used