WAGO WAGO-I/O-SYSTEM 750 Series Manual

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WAGO WAGO-I/O-SYSTEM 750 Series Manual Manual pdf 33 page image

WAGO-I/O-SYSTEM 750 Function Description 33750-495 3-Phase Power Measurement ModuleManualVersion 1.0.0Tamper DetectThe function ‘Tamper Detect’ may be used to detect a fault current caused by adefect machine or equipment.In general, the sum of the 3 actual phase currents Lx is equal to the neutral wire’scurrent in a faultless supply network. Therefore the I/O module calculates the sumof the 3 actual currents Lxi SUM Lx (t) = i L1 (t) + i L2 (t) + i L3 (t)and subtracts the actual neutral wire’s current. The result is the fault currenti SUM Lx (t) - i N (t)If it is higher than the set threshold (WAGO-I/O-CHECK or Parameter 32/33),signaling is carried out in the process image (PI).Type of current transformer!In order to achieve correct results all current transformers must be of the sametype!LimitsThe I/O module also offers limit monitoring. Limits (thresholds) for undervoltage,overvoltage and overcurrent can be set for each phase (WAGO-I/O-CHECK orRegister 36-38, parameters 23-31). Signaling is carried out in the process image(PI).4.4 Measuring Errors and AccuracyThe measuring errors of the I/O module are specified in the table below. Thevalues already take into account the errors caused by the differential connectionmethod (0.1%) and the calibration tolerance (0.1%). They apply to the entiretemperature range of 0 to 55 °C and to frequencies of 45 to 65 Hz. Outside thisfrequency range, the error is max. 2%.‘Rogowski’ coils generate a frequency depending signal which increases with thefrequency. This effect is corrected however by the ‘Rogowski’ variant 750-495/000-002 for the coils RT500 and RT2000.