GE IC3645SP4U400N3 Benutzerhandbuch

SX TRANSISTOR CONTROL

 

 

 

Page 8

 

 

January 2000 

Section 2.1.7 On-Board Coil Drivers & Internal Coil 
Suppression 
 

Coil drivers for the LINE and SP contactors 

are on-board the control card. These contactors must have 

coils rated for the vehicle battery volts. 

 

Section 2.2 System Protective Override 
 
Section 2.2.1 Static Return to Off (SRO) 
 

This inherent feature of the control is designed to require 

the driver to return the directional lever to the neutral 

position anytime he leaves the vehicle and returns. 

Additionally, if the seat switch or key switch is opened, the 

control shuts off and cannot be restarted until the 

directional lever is returned to neutral. A time delay of 

approximately 2 seconds is built into the seat switch input 

to allow momentary opening of the seat switch, if a bump is 

encountered. 

 
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 less than 3.0 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, and maintain the 

transistors within their temperature limits. Even at a 

reduced current limit, the vehicle will normally be able to 

reach sufficient speed.  As the control cools, the thermal 

protector will automatically reset, returning the control to 

full power. 

 
Section 2.2.5 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 claim 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.