Document ID: chunk:federal_register_of_legislation:F2023L01526:body:0:p52
Version: federal_register_of_legislation:F2023L01526
Segment Type: other
Provision Reference: 
Character Range: 145476–148504

of the REESS of the vehicle in accordance with paragraph 5.2.2. above.

       5.2.5.2. The steps of the procedure in paragraph 5.2.3. above shall be repeated.

       5.2.5.3. Before the completion of the soak period, the measuring chamber shall be purged for several minutes until a stable hydrogen background is obtained. The enclosure mixing fan(s) shall also be turned on at this time.

       5.2.5.4. The hydrogen analyser shall be zeroed and spanned immediately prior to the test.

       5.2.5.5. At the end of the soak the REESS shall be moved into the measuring chamber.

       5.2.5.6. The REESS shall be charged according to the failure charge procedure as specified in paragraph 5.2.5.9. below.

       5.2.5.7. The chamber shall be closed and sealed gas-tight within two minutes from electrical interlock of the failure charge step.

       5.2.5.8. The start of a failure charge for hydrogen emission test period begins when the chamber is sealed. The hydrogen concentration, temperature and barometric pressure are measured to give the initial readings CH2i, Ti and Pi for the failure charge test.

        These figures are used in the hydrogen emission calculation (Annex 8, paragraph 6.). The ambient enclosure temperature T shall not be less than 291 K and no more than 295 K during the charging failure period.

       5.2.5.9.  Procedure of charging failure

       The charging failure is carried out with a suitable charger and consists of the following steps:

           (a) Charging at constant power during t'1,

           (b) Charging at maximum current as recommended by the manufacturer during 30 minutes. During this phase, the charger shall supply maximum current as recommended by the manufacturer.

       5.2.5.10. The hydrogen analyser shall be zeroed and spanned immediately before the end of the test.

       5.2.5.11. The end of test period occurs t'1 + 30 minutes after the beginning of the initial sampling, as specified in paragraph 5.2.5.8. above. The times elapsed are recorded. The hydrogen concentration, temperature and barometric pressure are measured to give the final readings CH2f, Tf and Pf for the charging failure test, used for the calculation in paragraph 6. below.

       6. Calculation

       The hydrogen emission tests described in paragraph 5. above allow the calculation of the hydrogen emissions from the normal charge and charging failure phases. Hydrogen emissions from each of these phases are calculated using the initial and final hydrogen concentrations, temperatures and pressures in the enclosure, together with the net enclosure volume.

       The formula below is used:

       Where:

                     MH2 = hydrogen mass, in grams

                     CH2 = measured hydrogen concentration in the enclosure, in ppm volume

                     V = net enclosure volume in cubic metres (m3) corrected for the volume of the vehicle, with the windows and the luggage compartment open. If the volume of the vehicle is not determined a volume of