Electric, Fuel Cell and Hybrid vehicles may contain many types of high voltage systems. Adequate barriers between occupants and the high voltage systems are necessary to provide protection from potentially harmful electric current and materials within the high voltage system that can cause injury to occupants of the vehicle during and after a crash. This SAE Recommended Practice is applicable to Electric, Fuel Cell and Hybrid vehicle designs that are comprised of at least one vehicle propulsion voltage bus with a nominal operating voltage greater than 60 and less than 1,500 VDC, or greater than 30 and less than 1,000 VAC. This Recommended Practice addresses post-crash electrical safety, retention of electrical propulsion components and electrolyte spillage.
This version of SAE J1766 represents a significant update to the April 2005 version that it replaces. The substantive revisions are summarized as follows:
- The definition of high voltage (and corresponding applicability of this Recommended Practice) has been updated to include upper limits of 1,500 VDC and 1,000 VAC, consistent with international convention.
- The references to crash test procedures and test conditions have been updated and clarified.
- Electrolyte spillage provisions have been updated to reflect international regulatory requirements.
- Component retention provisions have been updated to be consistent with the requirements of Federal Motor Vehicle Safety Standard (FMVSS) 305.
- The previous version of SAE J1766 included three alternatives for providing post-crash electrical safety - electrical isolation, low voltage, and low energy. This update provides a fourth option for post-crash electrical safety, specifically an electrical protection barrier option. This fourth option aligns with ECE R94 and R95, the current draft of the fuel cell vehicle (FCV) global technical regulation (GTR), ISO 6469-3, and the consensus of international regulatory and industry experts that electrical protection barriers are foundational to in-use and post-crash electrical safety. In order to expedite acceptance of the electrical protection barriers, requirements for these electrical protection barriers were developed to verify that adequate electric shock protection is still provided after the crash. Test methods and rationale for these requirements are provided in Appendix C.
- The time criterion for initiating verification of post-crash electrical safety was also changed from 5 seconds after the vehicle comes to rest to 10 seconds after initial impact. Basing the criterion on time after initial impact provides more accuracy in establishing the allowable time period and aligns the criterion with other international standards. The increase from 5 to 10 seconds accounts for the post-crash period where the vehicle or parts of the vehicle could still be moving.
- The test procedures now contained in Appendices A and B have been updated and expanded.
- The rationale for the 0.2 Joules low-energy option has been expanded and updated. This updated rationale is provided in Appendix D.