Usage:
General
The following troubleshooting guide is an aid in isolating trouble to the control box, actuator, plant wiring, or elsewhere. Troubleshooting beyond this level is recommended ONLY when a complete facility for control testing is available.
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The control can be damaged with the wrong voltage. When replacing a control, check the power supply, battery, etc., for the correct voltage. |
Troubleshooting Procedure
Table 6-1 is a general guide for isolating system problems. This guide assumes that the system wiring, soldering connections, switch and relay contacts, and input and output connections are correct and in good working order. Make the checks in the order indicated. Each system check assumes that the prior checks have been properly done.
Control Test And Calibration
General
Perform the following checks on the 705 Control. Then verify the functioning of set points and adjustments.
1. Connect the Set Point Programmer to the control in accordance with the instructions in Chapter 5. Verify that correct voltage and polarity are applied to the control. Verify that the programmer performs its power-up tests. Failure to perform the power up test indicates either the control or Set Point Programmer has failed. Replace the control and/or Set Point Programmer.
2. Press the SP key. The message "705 Speed Control P/N 5410-868" should appear. Failure indicates either the control and/or Set Point Programmer has failed. Replace the control and/or Set Point Programmer.
3. Select Menu D. Step through the menu to the Self Test Result step. Verify that the displayed value is 49. If any other value is displayed, replace the control.
4. Select Menu A. Verify that all set points are as recorded during installation. Repeat for Menus B,C and 1. If any differences are found, change the set point(s) to the correct value. Press the "=" key. The message "Set Points Saved" should be displayed. Remove power from the control for at least 10 seconds. Verify correct values were retained during power down. Failure indicates the control has failed and should be replaced.
Discrete Inputs
Perform the following test to verify the function of the Discrete Inputs. Do not perform these tests with the engine in operation. When reading the Set Point Programmer, be sure to update the display by pressing the up or down arrow.
1. Close the Run/Stop contact or apply 24 Vdc between terminals 8(-) and 9(+) to select Run. Select Run/Stop Switch Status on Menu D. The status should be closed. If the value does not change from closed to open when the Run/Stop switch is opened, verify the voltage at the control terminals. If correct voltage is verified, the control has failed and should be replaced.
2. Close the Idle/Rated contact or apply voltage to terminal 10(+). The Idle/Rated switch status should change from closed to open when the voltage is removed.
3. Continue as above with the Lower contact, terminal 11.
4. Continue as above with the Raise contact, terminal 12.
5. Close the Remote contacts, terminals 11 and 12. Remote Switch status should be Remote. If not, check 3 and 4 above to determine which input is incorrect.
6. Continue as above with the Alternate Dynamics, terminal 13.
7. Continue as above with the Raise/Lower Rate 3 contact, terminal 14.
Any discrete input with power applied should indicate a closed status. If proper voltage is determined at the terminal strip, failure indicates the control input is bad. Replace the control.
Remote Input
The following tests calibrate and verify the function of the Remote Input, Analog Input 1. When reading the Set Point Programmer, be sure to update the display by pressing the up or down arrow.
1. Connect a 4 to 20 mA or 1 to 5 Vdc source to terminals 18(+) and 19(-). If a mA source is used, a jumper must be installed across terminals 17 and 18. Connect a dc voltmeter across terminals 18(+) and 19(-). Optionally, a mA meter may be installed in series with the 4 to 20 mA source.
2. Set the source for 5.0 Vdc (20.0 mA) on the meter. Select Menu 1 on the Set Point Programmer.
3. Set the Calibration Key to 49. Select Remote Input Calibration on Menu 1.
4. Update the value on the display by pressing the up or down arrow until the display reads 20.00 ± 0.01 mA.
5. Set the source for 1.0 Vdc (4.0 mA). The Remote Input value should be 4.0 mA ± 0.2 mA. If the meter indicates proper voltages (or currents) are present on the Analog Input 1, but readings on the Set Point Programmer are incorrect, the 705 control is defective and should be replaced.
Rack Limiter Input
The following tests calibrate and verify the function of the Limiter Input, Analog Input 2. When reading the Set Point Programmer, be sure to update the display by pressing the up or down arrow.
1. Connect a 4 to 20 mA or 1 to 5 Vdc source to terminals 21(+) and 22(-). If a mA source is used, a jumper must be installed across terminals 20 and 21. Connect a dc voltmeter across terminals 21(+) and 22(-). Optionally, a mA meter may be installed in series with the 4 to 20 mA source.
2. Set the source for 5.0 Vdc (20.0 mA) on the meter. Select Menu 1 on the Set Point Programmer.
3. Set the Calibration Key to 49. Select Rack Limit Input Calibration on Menu 1.
4. Update the value on the display by pressing the up or down arrow until the display reads 20.00 ± 0.01 mA.
5. Set the source for 1.0 Vdc (4.0 mA). The Rack Limit Input value should be 4.0 mA ± 0.2 mA. If the voltmeter indicates proper voltages are present on the Analog Input 1, but readings on the Set Point Programmer are incorrect, the 705 control is defective and should be replaced.
Actuator Output
The following tests verify the actuator output of the control.
1. Select Run and Failed Speed Override on. (Terminal 9 has the correct voltage applied and "Failed Speed Override" on Menu 1 is on.) Connect a milliamp meter across terminals 3(+) and 4(-) if no actuator is connected. Connect the milliamp meter in series with the actuator if one is connected to the control. (Alternately, a dc voltmeter may be connected across the output, terminals 3(+) and 4(-), when an actuator is connected. The correct output currents must be computed using the voltage measured and the input resistance of the actuator.)
2. Select Menu 1 on the Set Point Programmer. Set the Calibration Key to "49".
3. Select Forward/Reverse Acting Actuator on Menu 1, and select Forward Acting.
4. Select the Start Fuel Limit set point on Menu C. Set Start Fuel Limit to 20%. The output current should be 42 ± 2 mA.
5. Set the Start Fuel Limit to 100%. The output current should be 210 ± 10 mA. If with all connections verified, the output of the control fails to perform as above, replace the control.
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To prevent possible death, serious injury, or damage to equipment resulting from engine overspeed, return the Failed Speed Override to off. |
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Speed Input
The following tests verify the operation of the Speed Input.
1. Connect an audio frequency signal generator to the speed signal input. Set the output level above 1.0 Vrms. Set the Number of Gear Teeth set point on Menu 1 to 60 (this causes the rpm values and Hertz values to be the same for ease of performing the tests).
2. Set the signal generator to 120 Hz. Read engine rpm value of 120 rpm on Menu D. Increase the signal generator frequency to 400 Hz. The value read should follow the signal generator frequency.
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To prevent possible damage to the engine, return the Number of Gear Teeth to the correct value. |
Aux Output
The following tests calibrate and verify the operation of the Aux Output.
1. Connect a mA meter across the Aux 4-20 mA Output, terminal 5(+) and terminal 6(-). Select Menu 1 on the Set Point Programmer.
2. Set the Calibration Key to 49. Select Aux Output Configuration on Menu 1, and select Actuator Percent.
3. Select Actuator Output on Menu D and record the value shown.
4. Select 20mA Aux Actuator Percent on Menu C and record the value. Then set to the same value recorded in step 3.
5. Select Aux Output Calibration on Menu 1 and update the value on the meter by pressing the up or down arrow until the meter reads 20.00 ± 0.01 mA.
NOTE: If 4mA Aux Actuator Percent and 20mA Aux Actuator Percent are the same value, the Aux Output will be 0 mA.
6. Select 20mA Aux Actuator Percent on Menu C and reset to the original value recorded in step 4.
7. Select 4mA Aux Actuator Percent on Menu C and record the value. Then set to the same value recorded in step 3. The mA meter should read 4.0 ± 0.1 mA. Failure of this test indicates a faulty 705 control, which should be replaced.
8. Select 4mA Aux Actuator Percent on Menu C and reset to the original value recorded in step 7.
Conclusion Of Test And Calibration Procedures
This completes the test and calibration chapter. Save the set points by pressing the "=" key on the Set Point Programmer. Power down the control for about 10 seconds. Restore power and verify that all set points are as recorded.
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To prevent possible damage to the engine resulting from improper control settings, make sure you save the set points before removing power from the control. Failure to save the set points before removing power from the control causes them to revert to the previously saved settings. |
Disconnect the Set Point Programmer from the control. Close the cover over J1 and retighten the retaining screw.
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TO PROTECT AGAINST POSSIBLE PERSONAL INJURY, LOSS OF LIFE, and/or PROPERTY DAMAGE WHEN STARTING THE ENGINE, BE PREPARED TO MAKE AN EMERGENCY SHUTDOWN to protect against runaway or overspeed should the mechanical-hydraulic governor(s), or electric control(s), the actuator(s), fuel control(s), the driving mechanism(s), the linkage(s), or the controlled device(s) fail. |
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System Troubleshooting
