Document ID: chunk:federal_register_of_legislation:F2025L00028:reg:3:p10
Version: federal_register_of_legislation:F2025L00028
Segment Type: reg
Provision Reference: reg 3 (pt 10/11)
Character Range: 146844–150059

isolation (Ri) is calculated according to the following formula:

              Ri = Ro*Ub*(1/U1' – 1/U1)

         Figure 5
         Measurement of U1'

              If U2 is greater than U1, insert a standard known resistance (Ro) between the positive side of the high voltage bus and the electrical chassis. With Ro installed, measure the voltage (U2') between the positive side of the high voltage bus and the electrical chassis (see Figure 6 below). The electrical isolation (Ri) is calculated according to the following formula:

           Ri = Ro*Ub*(1/U2' – 1/U2)

       Figure 6
       Measurement of U2'

              5.2.2.3.5. Fifth step.

               The electrical isolation value Ri (in Ω) divided by the working voltage of the high voltage bus (in V) results in the isolation resistance (in Ω/V).

               Note: The standard known resistance Ro (in Ω) should be the value of the minimum required isolation resistance (Ω/V) multiplied by the working voltage (V) of the vehicle plus/minus 20 per cent. Ro is not required to be precisely this value since the equations are valid for any Ro; however, a Ro value in this range should provide a good resolution for the voltage measurements.

              6. Electrolyte leakage

                An appropriate coating, if necessary, may be applied to the physical protection (casing) in order to confirm if there is any electrolyte leakage from the REESS resulting from the test. Unless the manufacturer provides means to differentiate between the leakage of different liquids, all liquid leakage shall be considered as the electrolyte.

              7. REESS retention compliance shall be determined by visual inspection.

[1] The ellipsis (…) indicates the version(s) of the ADR in force at the 'Date of Manufacture'.
   Former titles of the Agreement:
Agreement Concerning the Adoption of Uniform Conditions of Approval and Reciprocal Recognition of Approval for Motor Vehicle Equipment and Parts, done at Geneva on 20 March 1958 (original version);
Agreement concerning the Adoption of Uniform Technical Prescriptions for Wheeled Vehicles, Equipment and Parts which can be Fitted and/or be Used on Wheeled Vehicles and the Conditions for Reciprocal Recognition of Approvals Granted on the Basis of these Prescriptions, done at Geneva on 5 October 1995 (Revision 2).

 [2] As defined in the Consolidated Resolution on the Construction of Vehicles (R.E.3.), document ECE/TRANS/WP.29/78/Rev.6, para. 2 -
https://unece.org/transport/standards/transport/vehicle-regulations-wp29/resolutions
 [3] The distinguishing numbers of the Contracting Parties to the 1958 Agreement are reproduced in Annex 3 to the Consolidated Resolution on the Construction of Vehicles (R.E.3), document ECE/TRANS/WP.29/78/Rev. 3, Annex 3 -
https://unece.org/transport/standards/transport/vehicle-regulations-wp29/resolutions
 [4] Until 30 September 2000, for the purposes of the test requirements, the range of normal longitudinal adjustments shall be limited such that the H-point lies within the length of the door aperture.
[2] 1 Distinguishing number of the country which has granted/extended/refused/withdrawn approval (see approval provisions in