During FPSO conversion project, the ship side system - 440LV Emergency Board, 65KA was retained and it was planned that a new generator to be connected to 440V emergency board. The new 1500kVA generator with same capacity as existing but lower reactance (11% compared to existing 15%) leads to higher fault level. Before any studies were carried out, generator was already ordered to meet deadlines.
PowerQ carried out analyses using SKM Power Tools software to determine the maximum fault currents under various scenarios including emergency operation. It was found that the short circuit level in 440 LV Emergency Board increased to 69kA thus rendering existing switchboard non-compliant.
Based on PowerQ's recommendation, the switchboard was replaced to meet the increased kA rating. As FPSO modifications occur, the load flow and short circuit calculation shall be (re) performed to identify any potential issues which may lead to Non Compliance to IEC and Class, and costly delays.