Hand-held trimmers are operated for

Hand-held trimmers are operated for 15 h at a voltage equal to 1,1 times the highest rated voltage or 1,1 times the upper limit of the rated voltage range, and then for 15 h at a supply voltage equal to 0,9 times the lowest rated voltage or 0,9 times the lower limit of the rated voltage range. The machine may be operated for a number of periods in order to achieve the 15 h operating time. For machines that can be operated in various positions in accordance with 8.14.2, the test may be conducted in any single orientation or distributed in various orientations for each 15 h test duration.