Measuring the minimum braking ratio and braking distance

Measuring the minimum braking ratio and braking distance

(In accordance with DIN norm 0015161 and FEM)

In accordance with DIN 0015161 and FEM, when checking the brakes the minimum braking ratio must be recorded using a decelerometer (motometer, dynometer or similar). The maximum permissible braking distances are listed here as comparative values.

Test requirements

Braking must take place on a level, dry, horizontal concrete track or similar. If the truck has an operator platform, it must be occupied by the driver when recording the braking. All industrial trucks are recorded laden with the max. permissible load. Tow trucks are recorded without attachments and without load. The load lifting device must be in the transportation position, i.e. it must be freely raised in the home position as low as possible. The mast is tilted back and retracted. Braking is recorded with the truck traveling forward and in reverse, facing straight ahead. Tow trucks are only recorded in the tow direction. The brakes are applied suddenly. The wheels should not slide or block during braking, and the truck should remain within the track.

Before checking the brakes:

For trucks with a traction controller, regenerative braking must be deactivated! • Set “Coasting Brake” setting to “0”. • Set “Max. Forward + Reverse” setting to “9”. • Set “Reduction Brake” setting to “0”. • EP series 1, 2 and 3: Remove the brake switch cable. • EP series 4 and 5: bypass brake pedal switch contact (7S11).

Braking distance recording

• Read the travel speed (laden) from the truck data plate or travel at max. speed for 5m along the measurement route and record the time taken.

Calculation formula: Time taken in seconds (t) over km/h (v): v = 18 / t [km/h]

• Accelerate the truck to maximum speed and from a fi xed marker brake until the truck comes to a halt. Record the braking distance and compare this with the max. permissible braking distance for your particular truck model.

Minimum braking recording

• Read the travel speed (laden) from the truck data plate or record the max. travel speed as indicated in paragraph 1 of Braking Distance Recording. • Attach a decelerometer (motometer, dynometer or similar) to the truck and prepare the truck for operation, note the manufacturer’s instructions. • Declerate the truck from the maximum speed.

If possible, brake trucks without an automatic brake (e.g. magnetic brake) so that the wheels are on the verge of sliding. For pedestrian guided trucks, suddenly set the tiller fully to the braking zone.

• Compare the braking ratio displayed as a percentage with the truck-dependent minimum braking ratio as indicated in the diagram.

Braking

Travel speed (v)

fi g. 157

A (see table group A) B (Tow trucks with 1 or 2 braked wheels) C (All-wheel braked tow trucks) D (see table group)