Digital Voltage Regulator Caterpillar

Fault Handling for Earlier Digital Voltage Regulators

Usage:

SR4B 1BN

The chart lists the serial number break between the earlier fault parameters and current fault parameters. All digital voltage regulator part numbers starting with 116 (116-XXXX) and some of the regulator part numbers starting with 130 (130-XXXX) use the earlier alarm/fault handling procedures. The current fault parameters/procedure is implemented on all versions of the digital voltage regulator built after March 1996. Another method to determine if a digital voltage regulator uses the current alarm/fault handling procedures is to check the PROM ID (parameter :91). A value of 1.03 or greater indicates use of the current alarm/fault parameters/procedures.

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Table 1
Earlier Fault Parameter Serial Number Break
Regulator Part Number	Earlier Fault Parameter Serial Number
130-3471	LBNBA0001-0123
130-3472	LBNBB0001-0301
130-3473	LBNBC0001-0176
130-3474	LBNBD0001-0190
130-3475	LBNBE0001-0392
130-3476	LBNBF0001-0238
116-XXXX	All

Fault Identification (For Earlier Digital Voltage Regulator)

Check the excitation.
1. Use a multimeter across the exciter field outputs F1 and F2. A multimeter should be set for VDC. Another way to verify that the regulator is providing excitation to the generator is by looking at parameter :55. Parameter :55 describes excitation current.
  Expected Result: The digital voltage regulator is providing the excitation to the generator.
  Results:
  - OK: Go to Step 2.
  - NOT OK: Go to Step 4.
Check the status of the alarm.
1. Check the display on the digital voltage regulator.
2. Check the status of the alarm output.
  Expected Result: The display on the regulator is flashing or the alarm output is off (open circuit). When alarm output is off, an alarm is active.
  Results:
  - OK: Go to Testing And Adjusting, "Fault Handling For Earlier Digital Voltage Regulator", section Alarm Clearing (For Earlier Digital Voltage Regulator).
  - NOT OK: Go to Step 3.
Check the alarm fault log.
1. Check the status of the alarm fault log. The alarm fault log is described by parameter :95.
  Expected Result: The alarm fault log shows "0000".
  Results:
  - OK: The alarm fault log shows "0000". No new alarm has occurred. STOP.
  - NOT OK: Go to Testing And Adjusting, "Fault Handling For Earlier Digital Voltage Regulator", section Alarm Clearing (For Earlier Digital Voltage Regulator).
Check the status of the fault.
1. Check the display on the digital voltage regulator.
2. Check the status of the fault output.
  Expected Result: The display on the regulator is flashing or the fault output is off (open circuit). When fault output is off, a fault is active.
  Results:
  - OK: A shutdown fault has occurred and is active. No new faults will be detected until active shutdown fault is reset. Go to Step 5.
  - NOT OK: Go to Testing And Adjusting, "Troubleshooting".
Check the shutdown fault log.
1. Check the number logged in the shutdown fault log. The shutdown fault log is described by parameter :92. Check the flashing number on the display.
  Expected Result: The number starts with a 7 (7xx).
  Results:
  - OK: The number starts with a 7 (7xx). A resettable fault has occurred. It can be reset without removing power by activating either shutdown fault reset, parameter :96 or the external fault reset switch. The fault can also be reset by cycling the power to 24 VDC power inputs ("B+"/"B-"). Note, that if the engine is running when the fault is reset the digital voltage regulator will provide excitation to the generator when the fault is reset. Go to Step 6.
  - NOT OK: Go to Step 7.
Check the status of the shutdown fault reset.
1. Select parameter :96 which describes shutdown fault reset. Depress the function key in order to reset the fault.
  Expected Result: Shutdown fault reset has been activated.
  Results:
  - OK: Shutdown fault reset has been activated. The fault output driver is reset and the unit is operational. The display continues to flash and the fault is still logged in the shutdown fault log, parameter :92. A flashing display indicates a fault in the shutdown fault log, parameter :92. New faults may be detected again. Go to Testing And Adjusting, "Fault Handling For Earlier Digital Voltage Regulator", section Fault Clearing (For Earlier Digital Voltage Regulator).
  - NOT OK: Shutdown fault reset has not been activated. Go to Step 5.
Check the shutdown fault log.
1. Check the number logged in the shutdown fault log. The shutdown fault log is described by parameter :92. Check the flashing number on the display.
  Expected Result: The number starts with an 8 (8xx).
  Results:
  - OK: The number starts with an 8 (8xx). A non-resettable fault has occurred. This fault is resettable only after removing all power to the digital voltage regulator, troubleshooting and correcting the problem, and reapplying the power. Go to Testing And Adjusting, "Fault Handling For Earlier Digital Voltage Regulator", section Fault Clearing (For Earlier Digital Voltage Regulator).
  - NOT OK: The number logged in the shutdown fault log, parameter :92 or flashing on the display starts with a 9 (9xx). A severe fault has occurred. The unit must be replaced. STOP.

Alarm Clearing (For Earlier Digital Voltage Regulator)

An alarm has occurred but the digital voltage regulator is still operational. No new alarms will be recorded until the present alarm is cleared. A 6xx number is flashing on the display and logged in the alarm fault log, parameter :95. Troubleshoot per the specific alarm description in service manual.

Note: If power is removed with an active fault, upon power-up the display will stop flashing. However, the fault will remain in the alarm fault log, parameter :95.

If you want to reset and clear the alarm, clear the alarm/fault by selecting parameter :94 on the display and pressing the function key. The digital voltage regulator screen should blank briefly, stop flashing and return to parameter :94. The Alarm Fault Log in parameter :95 should be cleared to "0000" and the alarm driver output should be reset. This also affects the values in parameters :92 and :93.

Fault Clearing (For Earlier Digital Voltage Regulator)

A shutdown fault has occurred. A 7xx or 8xx number is flashing on the display. A 7xx or 8xx number is logged in the shutdown fault log, parameter :92. Troubleshoot per the specific fault description.

Note: If power is removed with an active fault, upon power-up the display will stop flashing. However, the fault will remain in the shutdown fault log, parameter :92.

Reset a 7xx fault by selecting parameter :96 and depress the function key to reset the fault. Reset an 8xx fault by removing all power to the digital voltage regulator, troubleshooting and correcting the problem, and reapplying the power.

After the fault has been reset, clear the alarm/fault by selecting parameter code :94 on the display and pressing the function key. The digital voltage regulator screen should blank briefly, stop flashing and return to parameter :94.

The alarm/fault log in parameter :95 should be cleared to "0000". The fault value in parameter :92 is moved to parameter :93 and parameter :92 is cleared to "0000".

Note: In order to clear previous fault (parameter :93), select parameter :94 on the display and press the function key. Parameter :93 is cleared to "0000". Alarm log parameter :95 is also cleared to "0000" again.