Unitech Power Systems AS has recently provided assistance with investigating the cause of electric vehicle chargers malfunctioning in P-Siddis – a parking garage in Stavanger, Norway. Measurements showed high levels of conducted noise – so called “common mode” voltages – that caused the chargers’ contactor to switch on and off without stop.
During the troubleshooting the source of noise was identified to be variable speed drives for the parking garage's exhaust fans. Mitigation measures have been proposed.
Electromagnetic interference from emissions sources in power systems can cause other electrical equipment to malfunction. Unitech Power Systems AS has long experience in troubleshooting and root cause analyses in power systems.