70 likes | 221 Views
RT 2c: EMF – Revision of magnetic field limits. simple assessment procedure for 3-phase Systems practical approach for measurements practical experiences Andreas Abart Energie AG Oberoesterreich also lecturer at TU Graz Asset management Power Quality & EMC
E N D
RT 2c: EMF – Revision of magnetic field limits • simple assessment procedure for 3-phase Systems • practical approach for measurements • practical experiences Andreas Abart Energie AG Oberoesterreich also lecturer at TU Graz Asset management Power Quality & EMC andreas.abart@netzgmbh.at Phone: +43 5 9070 2107 Abart-AT-RT.2c
1st. Step of Assessment: • simple Estimation (magnetic field: 1 mT/kA at 0.2 m distance) • No further Assessment in case occupational Exposure: • Electric fields at rated voltage < 250 kV • generators and transformers • Any wire at maximum current < 1 kA (50 Hz) • Compliance demonstrated? – Yes => End of Assessment • 2nd. Step of Assesment: • regarding given compensation effects from parallel wires. • Compliance demonstrated? – Yes => End of Assessment • 3rd. Step of Assesment (expert job): • Measurements including all shielding effects
occupational exposure (1000µT) General public/office(200µT)
ASSESSMENT: • Estimation, • Calculation • Measurement • Calculation & Measurement
Measurements in Practice • applying summation Formula according to ICNIRP Guidelines => Exp=Sum of Signal + Sum of noise • following Jokelas approach 2003 (regarding phase of each spectral component) is helpful but complicating processing of measurement data. • regarding spectral components > X% of limits like standards for welding equipement suggest. • RMS of spectral components weighted on limits following the EN 50366 approach (household appliances)