BASIC OPERATION AND FEATURES
SX TRANSISTOR CONTROL
Page
10
January 1999
goes into severe cutback, the “Must Pulse To Time” feature
will inhibit the lA timer.
Section 2.2.6 Thermal Protector (TP)
This temperature sensitive device is internal to the power
transistor (Q1) module. If the transistor's temperature
begins to exceed the design limits, the thermal protector
will lower the maximum current limit, and maintain the
transistors within their temperature limits. Even at a
reduced current limit, the vehicle will normally be able to
reach sufficient speed to initiate 1A operation, thereby
allowing the control to cool. As the control cools, the
thermal protector will automatically reset, returning the
control to full power.
Section 2.2.7 Low Voltage
Batteries under load, particularly if undersized or more
than 80 percent discharged, will produce low voltages at
the control terminals. The SX control is designed for use
down to 50 percent of a nominal battery voltage of 36-84
volts, and 75 percent of a nominal battery voltage of 24
volts. Lower battery voltage may cause the control to
operate improperly, however, the resulting PMT should
open the Line contactor, in the event of a failure.
Section 2.3 Diagnostics
Section 2.3.1 Systems Diagnostics
The control detects the system's present operating status
and can be displayed to either the Dash Display or the
Handset. There are currently over 70 status codes that are
available with SX systems using Traction and Pump
controls and Truck Management Module (TMM). Along
with the status code display from the TMM, the SX control
is capable of reducing the current to the motor, alerting the
operator of a critical fault condition.
Section 2.3.2 Status Codes
Section 2.3.2a Standard Status Codes
The SX traction control has over 30 Status Codes that
assist the service technician and operator in trouble
shooting the vehicle. If mis-operation of the vehicle occurs,
a status code will be displayed on the Dash Display for
vehicles so equipped, or be available by plugging the
Handset into the “y” plug of the logic card.
With the status code number, follow the procedures
outlined in DIAGNOSTIC STATUS CODES to determine the
problem and a solution.
Note: The Status Code Instruction Sheets do not purport to
cover all possible causes of a display of a "status code ".
They do provide instructions for checking the most direct
inputs that can cause status codes to appear.
Section 2.3.2.b Stored Status Codes
This feature records the last 16 "Stored Status Codes" that
have caused a PMT controller shut down and/or disrupted
normal vehicle operation. (PMT type faults are reset by
cycling the key switch). These status codes, along with the
corresponding BDI and hourmeter readings, can be
accessed with the Handset, or by using the RS 232
communications port and dumping the information to a
Personal Computer terminal.
Section 2.3.3 Hourmeter Readings
This feature will display the recorded hours of use of the
traction and pump control to the Dash Display each time
the key switch is turned off.
Section 2.3.3.a Maintenance Alert & Speed Limit
This feature is used to display Status Code 99 and/or
activate a speed limit when the vehicle operating hours
match the hours set into the maintenance alert register.
This feature is set with the Handset using Functions 19, 20
and 21. The operator is alerted that maintenance on the
vehicle is required.
Section 2.3.4 Battery Discharge Indication (BDI)
The latest in microprocessor technology is used to provide
accurate battery state of charge information and to supply
passive and active warning signals to the vehicle operator.
Features and functions:
•
=
Displays 100 to 0 percent charge.
•
=
Display blinks with 20% charge. Disables pump circuit
with 10% charge. Auto ranging for 36/48 volt operation.
Adjustable for use on 24 to 80 volts.
Section 2.3.4.a Internal Resistance Compensation
This feature is used when the Battery Discharge Indicator
is present. Adjustment of this function will improve the
accuracy of the BDI.
Section 2.3.5 Handset
This is a multi-functional tool used with the LX, ZX, and SX
Series GE solid state controls. The Handset consists of a
Light Emitting Diode (LED) display and a keyboard for data
entry. Note, for ordering purposes, a separate Handset part
is required for SX controls.
Features and functions: