Interpretation ID: nht79-1.16

DATE: 10/25/79

FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA

TO: SEV Corporation

TITLE: FMVSS INTERPRETATION

TEXT:

Mr. H. J. T. Young Vice President - Technical Affairs SEV Corporation 33201 Harper Avenue St. Clair Shores, Michigan 48082

Dear Mr. Young:

This is in reply to your letter of September 24, 1979, to Mr. Vinson of this office asking for an interpretation of Federal Motor Vehicle Safety Standard No. 108.

You referred to the SAE standard on motorcycle headlamps, J584, which specifies that the "bulb or unit shall be operated at its rated voltage during the photometric test." You asked whether the "rated voltage" of J584 is the same rated voltage of ECE Regulation 37 when the bulb in question is a European bulb bearing an E mark signifying compliance with Regulation 37.

The term "rated voltage" is not defined by J584 or by the corresponding standard on sealed beam headlamps, J579c. It is our opinion, however, that "rated voltage" is the equivalent of "design voltage" on the basis of the SAE standard that covers bulbs used in sealed beam headlamps, J573d, Lamps Bulbs and Sealed Units. Table 2 of J573d lists voltages for such headlamps under the heading of "Design."

We realize that your question arises in the context of recent testing by NHTSA of Cibie headlamps, incorporating European H4 halogen bulbs, for compliance with the requirements of Standard No. 108 for motorcycle headlighting. NHTSA tested these headlamps at 12.8 volts and discovered that the maximum allowable 5000 candela at test point 4D-V was exceeded by many of the lamps tested. You raised the question whether NHTSA should not have tested at 12 volts, the "rated value" given by Regulation 37 for the H4 bulb, at which value all lamps tested by NHTSA would have complied at test point 4D-V.

We do not believe that NHTSA is required by J589 to test the H4 bulb at 12 volts. Regulation 37 specifies a "test voltage" of 13.2 for the H4 bulb, a point apparently recognized by EFPE Company's catalogue "Turned on Lighting" which gives wattage figures for the headlamps in question "at 13.2 design volts as specified by the bulb manufacturer." If anything, NHTSA was overly conservative in testing its lamps at 12.8 volts, for it is apparent that had it tested at 13.2 volts even more failures would have occurred.

As Roman Brooks explained to you, it has been the European practice as nearly as we can determine to test the H4 bulb at 12.8 volts, apparently in recognition that the higher voltage levels are closer to those generated by the electrical systems of the motor vehicles on which the headlamps are installed. Given this fact and Regulation 37's specification of 13.2 test volts, we do not believe that a lamp manufacturer could successfully argue in court that J584 was ambiguous and should be construed against NHTSA in any attempt by this agency to enforce motorcycle headlighting requirements on the basis of results of tests conducted at 12.8 volts.

Sincerely,

Frank Berndt Chief Counsel