Document ID: chunk:federal_register_of_legislation:F2014C01118:front:0:p17
Version: federal_register_of_legislation:F2014C01118
Segment Type: other
Provision Reference: 
Character Range: 49629–52677

of the line to the service brake actuator.
21.2.2.                          The input signal strength must be the final value of the applied signal and must be applied to the 'Control System' such that it rises from zero to 65 percent of the final value in not more than 0.22 second. In the case of air 'Brake System's' the input 'Control Signal' strength (kPa) will be measured at the trailer 'Control Line' coupling.
21.2.3.                          The output signal strength must be the final value of the signal generated for control of the 'Brakes' actuator and which must be reached in not more than two seconds. The output signal strength will be measured in the actuator attached to each output having a fundamentally different relation to the input. In the case of air 'Brake Systems' a  'Control Signal' path having additional pressure limiters, relay valves or other active devices will be considered as being fundamentally different.
21.2.4.                          Time response must be measured where necessary in accordance with part 15.
21.2.5.                          Where the 'Control System' is not installed on an actual trailer, it must be installed in an essentially identical manner, in the laboratory, with all bends, fittings and worst case line lengths and representative actuator volumes installed.
21.2.6.                          For the application test, clause 15.7, the actuator displacement must be the largest volume for which the 'Control System' is designed and it may be represented by an equivalent fixed volume.
21.2.7.                          The release test, clause 15.8, must commence at an actuator displacement corresponding to the largest volume for which the 'Control System' is designed. Alternatively the actuators may be replaced by an equivalent fixed volume.
21.2.8.                          All relevant test conditions pertaining to part 9 must be complied with.
21.2.9.                          The relationship between brake actuator volume and stroke must be measured and plotted from zero to full actuator stroke.
21.2.9.1.                    Where more than one actuator type is used, a plot for each actuator must be supplied. If several plots are shown on one graph, each plot must be identified and clearly related to the actuator details.
21.2.9.2.                    If the relationship between stroke and volume is not linear, all critical points must be measured and plotted.
21.2.9.3.                    The value of the maximum brake actuator design stroke and volume must be stated.
21.3.                                'Foundation Brakes'
21.3.1.                          The effectiveness of the 'Foundation Brakes' must be characterised by comparing the energy level of the signal provided to the 'Brakes' actuator against the output brake torque of the 'Brakes' device at not less than five points in the range 0.2 'E' to 1.0 'E'. These points must be equally spaced.  Where a test was not conducted at 1.0 'E', the torque from a test conducted at 0.8 'E' or greater may