| conditions under which the machine is operated in normal use, obtained at the following power input Pm of the vacuum motor:
Pm = 0,5 (Pf + Pi)
where
Pf is the input, in watts, when the machine has been operated for 3 min, fitted with the nozzle and hose giving the highest input;
Pi is the input, in watts, when the machine has been operated for 20 s with the nozzle sealed, immediately following the 3-minute-period with the nozzle open. Any valve or similar device used to ensure a flow of air to cool the motor in the event of a blockage of a main air inlet is rendered ineffective.
Pf and Pi are measured with the supply voltage adjusted to rated voltage, or to a voltage equal to the mean value of the rated voltage range if the difference between the limits of the rated voltage range does not exceed 10 % of the mean value of the range. If the difference between the limits of the rated voltage range exceeds 10 % of the mean value, the tests are carried out with the supply voltage set to the upper limit of the range.
The measurements are made with the machine fitted with a clean dust bag and filter and with the water container, if any, empty. If the machine is intended for use only with a hose, detachable nozzles are removed and the hose is laid out straight. If the machine is provided with a hose as an optional accessory, it is operated without the hose.
Electrically driven devices, if any, are in operation but are not in contact with the floor or any other surface or with the means used to seal the air inlet.
The normal load is equal to the mean load Pr for the electrically driven agitating device such as a motor driven brush determined in accordance with the following:
– the agitating device operates on a carpet as specified in IEC 60312-1;
– the mean load Pr is determined when using the device in the following way:
After setting the device, the device is moved twice over a distance of 5 m in the direction giving the highest load;
– the motor responsible for the airflow operates under the same conditions as for determining Pf , i.e. no airflow restrictions, and measurements are taken after 3 min;
– the device is adjusted to the carpet pile height;
– it is necessary to move the agitating device slowly across the carpet to avoid carpet damage.
Soiled water discharge pumps, if applicable, are operated as follows.
The pump delivers a continuous flow of water without any soiled water discharge hose attached to the soiled water outlet of the machines unless the discharge hose is permanently attached to the machine. The vacuum motor works during the test, unless an interlock device is provided to prevent combined operation of both motors. |