Document ID: chunk:federal_register_of_legislation:F2025L00028:reg:3:p7
Version: federal_register_of_legislation:F2025L00028
Segment Type: reg
Provision Reference: reg 3 (pt 7/11)
Character Range: 137964–141176

U22

                  This procedure is not applicable if the test is performed under the condition where the electric power train is not energized.

       Figure 2
       E.g. measurement of high voltage bus energy stored in X-capacitors

              4. Physical protection

              Following the vehicle impact test any parts surrounding the high voltage components shall be, without the use of tools, opened, disassembled or removed. All remaining surrounding parts shall be considered part of the physical protection.

              The jointed test finger described in Figure 3 shall be inserted into any gaps or openings of the physical protection with a test force of 10 N ± 10 per cent for electrical safety assessment. If partial or full penetration into the physical protection by the jointed test finger occurs, the jointed test finger shall be placed in every position as specified below.

              Starting from the straight position, both joints of the test finger shall be rotated progressively through an angle of up to 90 degrees with respect to the axis of the adjoining section of the finger and shall be placed in every possible position.

              Internal electrical protection barriers are considered part of the enclosure

              If appropriate a low-voltage supply (of not less than 40 V and not more than 50 V) in series with a suitable lamp should be connected, between the jointed test finger and high voltage live parts inside the electrical protection barrier or enclosure.

              Figure 3
       Jointed Test Finger

              Material: metal, except where otherwise specified

              Linear dimensions in mm.

              Tolerances on dimensions without specific tolerance:

                  (a) on angles: +0/-10 seconds;

              (b) on linear dimensions:

                (i) up to 25 mm: +0/-0.05;

                (ii) over 25 mm: ±0.2.

              Both joints shall permit movement in the same plane and the same direction through an angle of 90° with a 0 to +10° tolerance.

              The requirements of paragraph 5.3.7.1.3. of this Regulation are met if the jointed test finger described in Figure 3, is unable to contact high voltage live parts.

              If necessary a mirror or a fiberscope may be used in order to inspect whether the jointed test finger touches the high voltage buses.

              If this requirement is verified by a signal circuit between the jointed test finger and high voltage live parts, the lamp shall not light.

              4.1. Test method for measuring electric resistance:

           (a) Test method using a resistance tester.

                   The resistance tester is connected to the measuring points (typically, electrical chassis and electro conductive enclosure/electrical protection barrier) and the resistance is measured using a resistance tester that meets the specification that follows:

                   (i) Resistance tester: Measurement current at least 0.2 A;

                   (ii) Resolution: 0.01 Ω or less;

                   (iii) The resistance R shall be less than 0.1 Ω.

                  (b) Test method using DC power supply,