The Federal Motor Carrier Safety Administration has granted an temporary exemption period to allow commercial motor vehicle operators to use trailer-mounted electric brake controllers that monitor and actuate electric trailer brakes based on inertial forces developed in response to the braking action of the towing vehicle.
Each tow vehicle normally is equipped with a brake controller in the towing vehicle that applies the trailer brakes when the driver applies the towing vehicle’s brakes. Tow vehicle brake controllers usually are aftermarket devices that are manually adjustable to increase or decrease the amount of electric brake force applied to the trailer wheels to adjust for wet or dry road conditions and loaded or unloaded trailer condition. Electric brakes on commercial trailers will not operate unless the tow vehicle has a brake controller.
Innovative Electronics’ exemption application argued that technology developments in electronics have allowed the development of a self-contained electric brake control device that is mounted directly to the trailer, enabling it to monitor and actuate the brakes based on inertial forces developed in response to the braking action of the towing vehicle. The device is essentially an electric surge brake controller, with the electric power for the brakes provided by the tow vehicle, but the braking action of the trailer is controlled by the electric controller mounted on the trailer.
A trailer using this trailer-mounted electric brake controller did not meet the “operative at all times” requirement of the Federal Motor Carrier Safety Regulations, nor did they meet the “apply by a single application valve” requirement. During FMCSA’s temporary exemption period, motor carriers must meet the hydraulic surge brake requirements, substituting “trailer-mounted electric brake controller” for “surge brake” as follows:
- Trailer-mounted electric brake controllers are allowed on any trailer with a gross vehicle weight rating of 12,000 pounds or less when its GVWR does not exceed 1.75 times the GVWR of the towing vehicle; and any trailer with a GVWR greater than 12,000 pounds, but less than 20,001 pounds, when its GVWR does not exceed 1.25 times the GVWR of the towing vehicle;
- The GVW of a trailer equipped with a trailer-mounted electric brake controller may be used instead of its GVWR to calculate compliance with the weight ratios when the trailer manufacturer’s GVWR label is missing;
- The GVW of a trailer equipped with a trailer-mounted electric brake controller must be used to calculate compliance with the specified weight ratios when the trailer’s GVW exceeds its GVWR; and
- The trailer equipped with a trailer-mounted electric brake controller must meet FMCSR requirements.
For more information, go to www.regulations.gov; the docket number is FMCSA-2011-0022.