Thanks to all for the support. I really know now more than before. It is excellent that we have a forum for our boats. So in reply to Ian I think that Kimberlitt is right the Link 10 instrument is reading more than 300 Amperes when I moved the joystick of the thruster.
I know that you have to use the thruster only for small bursts but it is better to save the boat than the thruster. However I also thought that there is a fuse to stop the thruster as it is one for the anchor but there is not any and Amel replied to me that there is not possible to find a fuse that can withstand all these amperes. So be beware that you can damage the thruster and run into a fire disaster if you use it for longer period.
Now I will think my next step. I will use the thruster cautiously over the Easter vacations and then remove it from the boat for a closer look by an electrician and decide if I need to buy a new motor.
