The protection against overload is built in. When there's an overload, the engine automaticaly switch off. Next, you need to turn of the switch, wait a few minutes, open the machine and push on the green button.
An overload is an abnormal increase of the current. This may cause a heating or even destroy serveral parts in the machine.
W = I^2*R*t (Joule) (the influence of the time on the formula of heat development)
How it works: in the engine there's a thermal relay. The working of the thermal relay is based on the warping of a bimetal strip. These are 2 thin strips of metal sticked together. One of the metal strips hardly expands by heating, the other one much more. So by heating, the strip warps, this movement is used to trigger the overload mechanism.
You need to wait a few minutes to cool down the bimetal. The green button is necessary to close the electrical circuit.
