GE IC3645SP4U400N3 b Creep Speed, c Control Acceleration, Current Limit, d Auto Braking

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BASIC OPERATION AND FEATURES

SX TRANSISTOR CONTROL

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Section 2. FEATURES OF SX FAMILY OF TRANSISTOR MOTOR CONTROLLERS

Section 2.1 Performance

Section 2.1.1 Oscillator Card Features

Section 2.1.1.a Standard Operation

With the accelerator at maximum ohms or volts, the creep speed can be adjusted by Function 2 of the Handset or a trimpot. The field control section allows the adjustment of the field weakening level in order to set the top speed of the motor. This top speed function (Minimum Field Current) is enabled when the armature current is less than the value set by Function 24 and the accelerator input voltage is less than 1 volt. Top Speed can be adjusted by Function 7 of the Handset or a trimpot.

The percent on-time has a range of approximately 0 to 100 percent. The SX controllers operate at a constant frequency and the percent on-time is controlled by the pulse width of the voltage / current applied to the motor circuits.

Section 2.1.1.b Creep Speed

With the accelerator at maximum ohms or volts (approximately 3.7 to 3.5 VDC), the creep speed can be adjusted by Function 2 of the Handset. At creep speed, the ON time can decrease to approximately 5%, with the OFF time at approximately 95%. At full transistor operation, this condition will be reversed (short OFF time, long ON time). This variation of ON and OFF time of the oscillator varies the voltage applied to the motor, thereby varying the speed of the motor for a given load.

Section 2.1.1.c Control Acceleration

This feature allows for adjustment of the rate of time it takes for the control to accelerate to 100% applied battery voltage to the motor on hard acceleration. Armature C/A is adjusted by Function 3 from 0.1 to 22 seconds.

Section 2.1.2 Current Limit

This circuit monitors motor current by utilizing sensors in series with the armature and field windings. The information detected by the sensor is fed back to the card so that current may be limited to a pre-set value. If heavy load currents are detected, this circuit overrides the oscillator and limits the average current to a value set by Function 4 and Function 8 of the Handset. The C/L setting is based on the maximum thermal rating of the control. Because of the flyback current through 3REC, the motor current is usually greater than battery current, except at 100% ON time.

Section 2.1.3 Braking

Section 2.1.3.a Plug Braking

Section 2.1.3.b Regenerative Braking to Zero Speed

 

 

Slow down is accomplished when

 

 

reversing direction by providing a

 

 

small amount of retarding torque for

Q2

 

deceleration. If the vehicle is

 

ARM moving, and the directional lever is

 

 

moved from one direction to the

 

 

other, the regen signal is initiated.

 

Q1

Once the regen signal has been

 

initiated, the field current is

 

 

Figure 5

 

increased (armature circuit shown in

 

 

Figure 5). Armature current is

regulated to the regen current limit as set by Function 9. As the vehicle slows down, the field current continues to increase, and transistor Q2 begins to chop. The field current will increase until it reaches a preset value set by Function 10, and transistor Q2 on-time will increase until it reaches 100% on-time. Once both of the above conditions have been met, and regen current limit can no longer be maintained, the braking function is canceled. The fields will then reverse, and the control reverts back to motoring. Part of the energy produced by the motor during regen is returned to the battery, and part is dumped in the motor as heat.

Section 2.1.3.c Pedal Position Plug Braking

This feature allows control of the plugging distance based on pedal position when there has been a “directional switch" change. Pedal position will reduce the regenerative current to the "value set by this function" as the accelerator is returned to the creep speed position. Maximum regen current is obtained with the accelerator in the top speed position.

Section 2.1.3.d Auto Braking

This feature is enabled by initiating a "neutral position" using either the directional switch or the accelerator switch. Once activated, Auto Braking operates similar to Pedal Position Plug Braking and is adjusted by using Function 21 of the Handset.

Section 2.1.4 Auxiliary Speed Control

Section 2.1.4.a Field Weakening

This function allows the adjustment of the field weakening level in order to set the top speed of the motor. The function is enabled when the armature current is less than the value set by Function 24 and the accelerator input voltage is less than 1 volt. It is important to note that this function is used

January 2000

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Contents Installation and Operation Table of Contents 46-52 20-4041-45 57-62Basic Operation and Features Motor CharacteristicsFlexible System Application More Features with Fewer ComponentsSolid-State Reversing Slows with the increase of current in the field2 Current Limit 1.b Creep Speed1.c Control Acceleration 3.c Pedal Position Plug Braking4.c Proportional Operation for Dual Motor Vehicles 6 Steer Pump Contactor Time Delay4.b Speed Limits 5 Ramp Operation 5a Ramp StartSystem Protective Override 1 Static Return to Off SRO Diagnostics 1 Systems Diagnostics7 On-Board Coil Drivers & Internal Coil Suppression 2 Accelerator Volts Hold Off3 Hourmeter Readings 3.a Maintenance Alert & Speed Limit4 Battery Discharge Indication BDI 4.a Internal Resistance CompensationBasic Operation and Features Outline DRAWINGS, Elementary Drawings and INPUTS/OUTPUTS Part NumberArgument Outline SX-3 and SR-3 Package Size Drawings and INPUTS/OUTPUTS DRAWINGS, Elementary Drawings and INPUTS/OUTPUTS Control SectionConnections to Main Plug 23 PIN and Y Plug 12 PIN PINDiagnostic Status Codes 2.d. High Power Signals Level HP High-Level Signals Level HMedium-Power Signals Level MP Cable Spacing GuidelinesCleaner Reconnect plugs328A1777G1 General Troubleshooting Instructions Traction No seat switch or deadman switchTraction Control Codes Status CodeReverse directional switch is closed on Description of Status Cause of Status IndicationStart switch fails to close Accelerator depressed with noDirection selected KEY Negative Directional switches are closed at Both the forward and reverseSame time Start switch closed on power up after Initial key switch closureDischarged battery Motor field current is high on start up Reverse directionForward direction Volts DC Power supply is less than 10 volts Run modeMotor field current is too high during Traction Controller Slave/auxiliary control Transistor over temperature Open thermal protector TP orArmature transistor did not turn off Motor armature offset voltage is tooLow ProperlyThan 12% of battery volts Armature transistor did not turn onLook Ahead test for A2 volts less Motor field current is too low during Capacitor volts are low before the lineContactor closes Controller motor current sensor Input too low during runningLine driver input P2-17 is less Description Armature current exceeds Armature transistor limitVerify connection between the master control P21 Traction Status Code Symptom Temperature TMM Status CodesSteer Plug P5 pump is shorted to positive Plug P8 pump is shorted to positive Corrective Actions TROUBLE-SHOOTING Diagram YES Symptom PumpPossible Cause Transistor is over temperature Open thermal protector TP1 orSensor input is missing No power to pump motorPump Controller motor current Control rangeTurn off properly Power Transistor Q1 did notPower Transistor Q1 did not turn on With no pump contactor, controlCapacitor volts are low after the line Contactor closesController motor current Sensor input voltage polarityCheck Battery voltage is less than Voltage at capacitor 1C is less than VoltsTMM7A 3 TMM Pump Control Connections TMM7A Outline DrawingsAdjustable Features START-UP Display SequenceAccessing Stored Status Codes With GE Handset ActionRemarks Function Function 10 Field Current for Regen Internal Resistance Compensation Battery VoltsBattery volts Set units Function 16 Stall Trip Point with % ON-TIME PushFunction 19 Maintenance Code Tens and Units Hours SET Function 25 MonitorFunction 26 Base Ratio Function 49 Mode 1 Field Weakening Start Push Function 51 Mode 1 MAX Armature % onFunction 28 Stored Status Code Count Pointer Push Function 57 Mode 3 Field Weakening Start Function 52 Mode 2 Armature Controlled AccelerationFunction 55 Mode 2 MAX Armature % on Function 59 Mode 3 MAX Armature % onSummary of Current Limit Adjustments Field CurrentFunction Current Limit Function 14 not ApplicableFunction 16 Speed / Torque Compensation Function 49 Mode 1 Speed Limit 2 SL2 Push Speed / Torque Compensation Table Voltage SettingFunction 48 Mode 1 Controlled Acceleration Push Function 50 Mode 1 Speed Limit 3 SL3Function 55 not Applicable Function 53 Mode 2 Speed Limit 2 SL2Function 54 Mode 2 Speed Limit 3 SL3 Function 59 not ApplicableStandard Dash Displays Dash DisplaysApplication ConnectionsStart-Up Display Sequence Outline DrawingsTurn Angle Potentiometer Installation SetupOperation Degree Potentiometer for Steer Angle Input Degree Potentiometer Left Right RS-232 Memory MAP Tables Traction ControlRestrictions Function Reset to Zero Only HoursTens/Ones Reset to Zero Only Stored Status Code #5Reset to Zero Only Stored Status Code #6 Reset to Zero Only HoursThou/HunNone Dash Display Ratio2-1 Reset to Zero Only Stored Status Code #16Reset to Zero Only Dash Display CA-1 Dash Display FWS-1 None
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