Interpretation ID: nht94-7.23

DATE: March 25, 1994

FROM: Tilman Spingler -- Robert Bosch GMBH

TO: John Womack -- Acting Chief Counsel, NHTSA

TITLE: FMVSS 108, S4.Definitions, Integral Beam Headlamp Request for Interpretation

ATTACHMT: Attached to letter dated 5/5/94 from John Womack to Tilman Spingler (A42; Std. 108)

TEXT:

In this paragraph an integral beam headlamp is defined to be an indivisible optical assembly of lightsource, reflector and lens. In the case of High Intensity Discharge Headlamps where the lightsource is comprised of a bulb and associated electronic modules, it may in some cases not be feasible to integrate the ignition module and the control module in the headlamp housing because of space limitations. In the letter to TOYOTA of March 1991 these modules were permitted to be separately located, but permanently attached by cable at the time of assembly. When the ignition module is installed inside and the control module outside the headlamp housing they will be connected by a 4-core cable in one design. Are there requirements for this cable concerning indivisibility and integration, for example, may it be of the following? - soft cable, resistant to abrasion? - hard cable, resistant to cutting and abrasion? - armored cable? Maximum voltage on 2 cores will be 130 V AC in the on-mode of the headlamp, on the 2 other cores 400 V AC for 700 msec during ignition of the light source. These voltages are much lower than voltages on ignition cables for motor vehicle engines.