There are many codes for integration of renewable energy into grids. Nevertheless, the codes hardly discuss the transient response of grid connected generators and converters to maintain a power balance (equal input power and out power) in the DC link that connects the RE source to the grid under transient conditions. This is especially vital under a fault. The fault codes mainly focus on the system performance in an interval of tens to hundreds of msecs. However, It seems that there are needs for codes to govern the first few msecs of the system performance after a fault to maintain the balance and prevent the DC link over-voltage or over-current.