WAGO 750-494 Series Manual

Contents

74 Connect Devices WAGO-I/O-SYSTEM 750750-494 3-Phase Power Measurement ModuleManualVersion 1.2.0connected measuring instruments. FS shall be max. 10 for the 1 A module resp.max. 5 for the 5 A module.Note the max. continuous measuring current of 1 A resp. 5 A!The max. continuous measuring current of the module is 1 A resp. 5 A. If the usedtransformers allow greater secondary currents than 1 A resp. 5 A install additionaltransformers with an appropriate transforming ratio!7.3.2.4 Protection against Shock Hazard VoltagesNo hazardous voltage is produced when the 3-phase power measurement moduleis used as specified, with appropriate current transformers. Secondary voltage isonly a few Volts. Nevertheless, the following faults can result in high voltagelevels:• Open current path for one or more transformers• Disconnected/cut N conductor at the voltage measuring end of the 3-phasepower measurement module• General insulation faultsInstall protection against electric shock!All wiring for the measurement system shall be equipped with protection againstshock hazard voltages along with the corresponding safety signs!The 3-phase power measurement module permits a maximum voltage of 480 Vfor normal operating conditions. The voltages at the voltage inputs shall notexceed 480 V. For higher voltages use a transformer stage. This one however,shall not produce a phase angle shift (Yy0)!The 3-phase power measurement module is equipped with a protective impedanceof 1072 kΩ at the voltage measurement end. If the N conductor is not connected,and only one of the three voltage measuring terminals is under power, a voltage of230 VAC to ground is yielded in a 3-phase system with a phase-to-phase voltageof 400 VAC. This voltage is also present at the current measuring end and can bemeasured using a multimeter with 10 MΩ input resistance. This does not representan insulation fault.