I just noticed that you are in Croatia. This could be a problem because of the way the voltage is coming into your house.
In the US, 240V service is made up of 3 wires. two "hot" lines and one "neutral" line. Each of the hot lines carries 120V with opposite polarity. So, when you measure the voltage between the two hot lines, you see 240V. If you were to measure between one of the hot lines and the neutral line, you would see only 120V.
If I am correct, 240V service in Europe is entirely different. It does not use two 120V hot lines and one neutral line. Instead, it uses a single 240V hot line and a neutral line.
If your product is from the US and meant to be powered by 120V, you really need to have some sort of converter to change that 240V into 120V so that you can properly power the device. In the US, we can simply use one of the hot lines and the neutral to get 120V, but you might not have that luxury of your electricity does in fact come in as one 240V hot line and a neutral line.
I'm interesting in hearing more from you, and hope you have not damaged your controller by plugging it into a voltage source that is too large.