BASIC OPERATION AND FEATURES
SX TRANSISTOR CONTROL Page 8
July 1999
Section 2.2.2 Accelerator Volts Hold Off
This feature checks the voltage level at the accelerator
input whenever the key switch or seat switch is activated.
If, at start-up, the voltage is greater than 0.9 volts, the
control will not operate. This feature assures that the
control is calling for low speed operation at start up.
Section 2.2.3 Pulse Monitor Trip (PMT)
The PMT design contains three features which shut down,
or lock out, control operation if a fault conditions occurs
that would cause a disruption of normal vehicle operation:
•= Look ahead
•= Look again
•= Automatic look again and reset
The PMT circuit will not allow the control to start under the
following conditions:
•= The control monitors both armature and field FET's at
start-up and during running.
•= The control will not allow the line contactor to close at
start-up, or will drop it out during running, if either the
armature or field FET's are defective, so as to cause
uncontrolled truck movement.
Section 2.2.4 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 to 200 amps. As the
control cools, the thermal protector will automatically
reset, returning the control to full power.
Section 2.2.5 Low Voltage Detection
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 this status can be displayed to either the Dash Display
or the Handset. There are over 70 status codes that are
available with the SX systems using Pump and Traction
controls and the 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 2.3.2.a Standard Status Codes
The SX control has a wide variety of 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 from the status code
displayed when the Handset is plugged 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 appropriate corrective action.
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 2.3.4 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.
To Next Page
Loading...
