Magnetic compatibility of standard components for electrical installations: Tests on low voltage circuit breakers and contactors

The components of the electrical distribution system installed in the ITER Tokamak Building are subjected to a constant or slowly variable magnetic field, an environmental condition unusual for standard components used in low voltage electric distribution systems. Wide typologies of breakers, contactors and protection relays and a complete Low Voltage Distribution Board have been extensively tested to assess their behaviour when subjected to magnetic field. The results allowed to establish a magnetic field limit for their regular operation and to investigate upon overall functionality of a Low Voltage Distribution Board and upon the shielding effect of its iron structure.