NHTSA'S HEAVY DUTY VEHICLE BRAKE RESEARCH PROGRAM REPORT NUMBER 10 -- EVALUATION OF TRAILER ANTILOCK BRAKING SYSTEMS ELECTRICAL POWERING. INTERIM FINAL REPORT

Two means of powering trailer Antilock Brake Systems (ABSs) have been considered in this country. One approach is to provide separate electrical circuits; the other approach is based on the use of the existing 7-pin connector and the stoplamp circuit in it. A number of full-scale vehicle tests were conducted to evaluate the following areas: Electrical power available from tractor stoplamp circuits; ABS power requirements (amperage and minimum operating voltage); and ABS powering on doubles and triples (separate vs. shared power circuits; one vs. two ABS modulators per axle; effect of using light-emitting diode (LED) stoplamps in lieu of incandescent lamps). The tests showed that current ABSs require a minimum of from 7 to 10 volts to operate and draw approximately two to six amps. Given the minimum voltages necessary and the current draw of the ABSs and the stoplamps, some of the test tractors were not able to supply sufficient power for multiple trailers. Additionally, modulated brake applications of stoplamp powered trailer ABSs could, under certain conditions, result in trailer wheel lock-up. In testing double and triple combinations, it was found that improvements in ABS powering for trailers can be made by using full-time power on a separate circuit with increased wire size to the ABS and by using LED lights. Also found to be critical to powering trailer ABSs were the connectors between the tractor and the trailer and between the trailers.

Language

  • English

Media Info

  • Features: Appendices; Figures; References; Tables;
  • Pagination: 31 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00719517
  • Record Type: Publication
  • Source Agency: National Highway Traffic Safety Administration
  • Report/Paper Numbers: VRTC-82-0255, HS-808 249
  • Files: HSL, TRIS, USDOT
  • Created Date: Mar 28 1996 12:00AM