Shorts To Frame Test - prime mover smx45 Master Service Manual

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switching the battery voltage to the motor on and off very
quickly.
Overtemperature. Overtemperature
controller is from 185 degrees F (85 degrees C) and above.
At overtemperature, the drive current limit is linearly
decreased from full set current down to zero. Plug current is
not reduced to provide full truck braking under all thermal
conditions.
Undertemperature. When the transistor controller is
operating at less than -13 degrees F (-25 degrees C), the
current limit is cut back resulting in reduced travel speed.
Short Circuit or "Short". A short circuit is an unspecified
path in a circuit that provides unwanted full or partial
continuity between two or more locations in an electrical
circuit.
Example: Two insulated wires are physically next
to each other and the insulation has been worn off
each of the wires. Because the conductors inside
each wire are now touching each other, there is a
short circuit.
Example: A power cable from the battery to a
junction post in the truck has had the insulation
worn away. Because the wire conductors are
touching the frame, there is a short circuit of the
battery cable.

2.1.2. Shorts to Frame Test

"Shorts to frame" is an industry term for unintentional current
leakage paths between normally isolated electrical circuits
and their metal enclosures. Shorts to frame may be metallic
connections, such as a wire conductor contacting metal
through worn insulation. More often, shorts to frame are
resistive "leakage" paths caused by contamination and/or
moisture. These leakage paths can result in unwanted
electrical noise on the metallic truck structure and may result
in improper operation.
Shorts to frame can be caused by the following:
• Accumulation of dirt
• Battery electrolyte leakage
• Motor brush dust
Master Service Manual
F-code Section
PT S5.0
Electrical Functions
Version no T-code
002 SMX
of
2006-12-12
C-code
5000
the transistor
157