AS NZS 60335.2.31:2020 pdf free.Household and similar electrical appliances一Safety Part 2.31: Particular requirements for range hoods and other cooking fume extractors.
If the range hood is intended to be installed over a hob having four hob elements, the hob shall have two 2 kW electric elements at the back and two 1,5 kW electric elements at the front.
If the range hood is intended to be installed over a hob having six hob elements, the hob shall have three 2 kW electric elements at the back and three 1,5 kW electric elements at the front.
The layout of the hobs used in the tests is shown in Figure 101. The hobs are centrally situated with respect to the range hood.
Vessels, without lids, containing water are placed on the hob elements. The diameter of the vessels is approximately equal to that of the hob elements. The hob elements are operated to maintain vigorous boiling.
The appliance is also tested without the hob elements in operation.
For appliances delivered for installation with the control and filter boxes separate from the fan, the duct length on input and output shall be 4 times fan diameter. However, if the fan is intended to be mounted on the external structure of a building, the fan is not ducted on the output side.
11.7 Replacement:
Appliances are operated until steady conditions are established.
11.8 Addition:
The temperature rise limit for external enclosures and wood does not apply when the hob elements are in operation. When the appliance is tested without the hob elements in operation, only the temperature rises of the external enclosure and wood are measured, the temperature rise limit for wood being 65 K.
Temperature rises of lam pholders and the enclosure are also determined with the fan motor switched off and lights switched on. Enclosure temperatures are not measured within a distance of 35 mm around the lamp glass regardless of its shape.
For down-draft systems, the temperature rises shall not exceed the values given in Table 3 reduced by 15 K.AS NZS 60335.2.31 pdf download.