GA200 rapid rise of element temperature during start-up

Hi Cas, We have 2 GA200s with twin stages each. Both have the same problem of rapid raise of element temperature when starting them. In case of voltage fluctuation, it is not possible to restart them immediately since at 90 Celsius temperatures will raise rapidly to 160 Celsius! To start this units we normally have to wait till when both elements are at 45 Celsius. At this time, when starting the compressors there is a rapid raise in element temperature to 90 - 108 Celsius and later temperatures go down during loading. What could be the problem Cas?   Regards, Linus