Specifications

GENERAL MAINTENANCE INSTRUCTIONS

The SCR control, like all electrical apparatus, does have some thermal losses. The semiconductor

junctions have finite temperature limits above which these devices may be damaged. For these rea-

sons, normal maintenance should guard against any action which will expose the components to

excessive heat, such as steam cleaning; or which will reduce heat dissipating ability of the control,

such as restricting air flow.

The following DOS and DONTS should be observed:

Any controls that will be used in ambients of 100 F (40 C) or over should be brought to the

attention of the truck manufacturer.

All external components having inductive coils must be filtered. Refer to vehicle manufac-

turer for specifications.

The control should not be steam cleaned. In dusty areas, use low-pressure air to blow off the

control. In oily or greasy areas, a mild solution of detergent or denatured alcohol can be used

to wash off the control and then blow completely dry with low-pressure air. The control can

also be cleaned with Freon TF degreaser.

For the SCR panel to be most effective, it must be mounted against the frame of the truck.

The truck frame, acting as an additional heat sink, will give improved truck performance by

keeping the SCR control package cooler. The use of a heat-transfer grease (Dow Corning

340) is recommended.

Terminal boards and other exposed SCR control parts should be kept free of dirt and paint

that might change the effective resistance between points.

CAUTION: The truck should not be plugged when the truck is jacked up and the drive

wheels are in a free wheeling position. The higher motor speeds can create excessive

voltages that can be harmful to the control.

Do not hipot (or megger) the control. Unless the terminals of each semiconductor and card

are connected together, the control may be damaged. Refer to control manufacturer before

hipotting.

Use a lead-acid battery with the voltage and ampere hour rating specified for the vehicle.

Follow normal battery maintenance procedures, recharging before 80 percent discharged and

with periodic equalizing charges.