operations on fork lift trucks equipped with electronic assemblies

Instructions for the prevention of accidents and damage to equipment when performing servicing, checking and repair operations on fork lift trucks equipped with electronic assemblies

1. Safety measures

Observe t • he operating instructions, section “Repair”. • Remove all rings, bracelets and similar objects before commencing any operations on fork lift trucks. • Repairs, as well as removal and installation of electronic components and fuses must only be performed on a dead system. Unplug the battery plug or disconnect the battery. • Connect the battery and switch on control voltages only, if required for checking operations. Exercise care during all operations (hazard of arcing). • If not instructed otherwise, the vehicle must be jacked up for checking to allow the drive wheels to move freely. (Ensure absolutely that the vehicle cannot slip.)

2. Electric welding operations

Before commencing any electric welding operations on a fork lift truck, ensure that all control current plugs and all cable connections have been disconnected from the electronic assemblies, and that all electronic mounting boards have been removed. During electric welding operations on the vehicle, the welding current causes in the cables an inductive voltage with high voltage peaks which is liable to destroy the semi-conductors incorporated in the electronic assemblies.

3. Correct handling of electronic printed circuit boards

When removing or installing electronic mounting boards or when fi tting the test adapter ensure that the electric s • ystem is dead (switch off battery main switch and key switch), • the contact pins are not deformed, • the cooling on the multipoint connector corresponds with the coding on the mounting board, • the contacts of the mounting board and multipoint connector are facing each other correctly when there is no coding), • the mounting board is correctly inserted into the guide rail, • a seized mounted board is not removed or installed by force (contacts will be deformed), • Use a tool (brass sockets) for the removal of printed circuit boards which are fi tted by means of lugs.

4. Handling of electronic components (MOS-components, E-PROM and others)

These electronic components are very sensitive against static charges and might be destroyed by such static charges. Always ensure that the electronic components, when not required, are placed with their connecting contacts on metallic, bare supports, or that they are in conductive foam rubber. New electronic components are always supplied on a strip of conductive foam rubber and for transportation purposes the replaced electronic components must be set back into the conductive foam rubber.

5. Changing the EPROM

In case of varnished boards, do not exchange the EPROM. ! Do not bend or damage the connecting contacts of the EPROM!

Lift the EPROM equally out of the plug connector by putting the tool - order no. 081.0996 (plastic pliers) - under the narrow edges. When replacing the EPROM, ensure that the sides are correctly placed. EPROM and plug connector are marked by a notching.

6. Installation of heat-sensitive components

(Diodes, thyristors, transistors, cooling elements, etc.) Heat-sensitive components must be installed using heat conducting compound, heat-conducting mats or foils. Do only apply enough heat-conducting compound to the threads of electronic components or into tapped holes accepting such components, or onto the surfaces of cooling elements that the threads or any unevenness in the cooling element surfaces are just fi lled or evened out. If excessive heat-conducting compound is applied, the compound, which softens when the components become heated, will leak out (leaving hollows) thus impairing its heat conducting properties.

7. Cleaning operations

• Cleaning operations must only be performed on dead installations. Unplug the battery plug or disconnect the battery. • Do not use a steam jet when cleaning electronic components, but use lowpressure compressed air and a brush. • See SHB 0000.15.