18.7 Switches or other devices for motor reversal shall withstand the stresses occurring when the sense of rotation is reversed under running conditions where such a reversal is possible.Compliance is checked by the following test.The tool is operated at a voltage equal to rated voltage at no-load; the device for reversing the sense of rotation being in such a position that the rotor rotates in one direction at full speed.The direction of the rotation is then reversed, without the device resting in an intermediate "off" position.This operation sequence is performed 25 times.After the test, the switch shall have no electrical or mechanical failure. If the switch operates properly in the “on” and “off” positions at the end of the test, it is considered to have no mechanical or electrical failure.