INSTALLATION AND OPERATION
SX TRANSISTOR CONTROL
Page
12
Section 4.0 TROUBLESHOOTING AND DIAGNOSTIC STATUS CODES
Section 4.1 General Maintenance Instructions
The transistor 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 reasons, normal maintenance
should guard against any action which will expose the
components to excessive heat and/or those conditions
which will reduce the heat dissipating ability of the control,
such as restricting air flow.
The following Do’s and Don’t’s should be observed
:
Any controls that will be applied in ambient temperatures
over 100° F (40° C) should be brought to the attention of the
vehicle manufacturer.
All external components having inductive coils must be
filtered. Refer to vehicle manufacturer for specifications.
The wiring should not be directly steam cleaned.
In dusty
areas, blow low-pressure air over the control to remove
dust. In oily or greasy areas, a mild solution of detergent or
denatured alcohol can be used to wash the control, and
then low-pressure air should be used to completely dry the
control.
For the control to be most effective, it must be mounted
against the frame of the vehicle. The metal vehicle frame,
acting as an additional heat sink, will give improved vehicle
performance by keeping the control package cooler.
Apply
a thin layer of heat-transfer grease (such as Dow Corning
340) between the control heat sink and the vehicle frame.
Control wire plugs and other exposed transistor control
parts should be kept free of dirt and paint that might
change the effective resistance between points.
CAUTION: The vehicle should not be plugged when the
vehicle 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. 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 with periodic equalizing charges.
Visual inspection of GE contactors contained in the traction
and pump systems is recommended to occur during every
1000 hours of vehicle operation. Inspection is
Sept 2019
Updated
in drive equipment cabling:
The following are specific examples of level L signals used
•
DC busses less than 15 V and 250 mA
•
4 – 20 mA current loops
•
Digital signals whose logic levels are less than 15 V DC
•
Analog signals 0 through ±15 V
of:
Low-level signals are designated as
level L
. These consist
4.2.2.a Low-Level Signals (Level L)
contains recommendations for separating the levels.
classes, with specific examples of each. Section 4.2.3
Sections 4.2.2.a through 4.2.2.d define these levels and
classes.
Within those levels, signals can be further divided into
defining levels: low, high, medium power, and high power.
The signal/power carrying cables
are categorized into four
Section 4.2.2. Signal/PowerLevel
Definitions
a more trouble-free installation.
the planning stages to help ensure correct application and
On vehicle retrofits, level rules should be considered during
efficiently arrange mechanical
and electrical equipment.
On new installations, sufficient space should be allowed to
with these level separation rules.
recommends early planning of
cable routing that complies
To help ensure a lower cost, noise-free installation, GE
the level rules and cabling practices defined in this section.
locations of cables. They are
also responsible for applying
responsible for the mechanical and environmental
The customer and customer’s representative are
Section 4.2.1 Application Responsibility
standards.
separation and routing practices, consistent with industry
reduce this interference, GE recommends specific cable
interfere with a microprocessor-based control system. To
Electrical noise from cabling of various voltage levels can
Section 4.2 Cable Routing and Separation
vehicle.
attributed to welding while the control is installed in the
during the warranty period when such failures are
control(s) in the vehicle. GE will not honor control failures
performed on the vehicle after the installation of the
GE does not recommend that any type of welding be
and that the tips are intact and free of contaminants.
recommended to verify that
the contactors are not binding
