AL Fault Codes rely upon certain setpoints. Refer to Systems Operation, "Service Mode" for more information on setpoints. AL Fault Codes are not stored in the fault log of the GSC+P. Many of the AL Fault Codes are programmable as a fault alarm or as a shutdown fault. In order to show the severity of the fault, the AL Fault Codes are accompanied by a fault alarm indicator. Also, the fault shutdown indicator on the GSC+P can accompany an AL Fault Code. The AL Fault Codes and the related setpoints are described in the paragraphs that follow.
AL1 High Water Temperature Alarm - A high water temperature shutdown is issued by the GSC+P when the engine coolant temperature increases to about 6°C (11°F) from setpoint P015. The fault alarm indicator will FLASH. The AL1 fault code is shown on the upper display after the "Alarm Fault Codes" key is pressed.
P015 is the setpoint for a high water temperature shutdown. This setpoint sets the coolant level temperature. The GSC+P uses the temperature in order to declare that a shutdown fault due to high water temperature is present. When the setpoint is reached, the dedicated shutdown indicator for high water temperature FLASHES and the engine is shutdown.
AL2 Low Water Temperature Alarm - When the engine coolant temperature decreases to setpoint P016, the GSC+P issues a low water temperature alarm. Setpoint P016 is the setpoint for the low water temperature alarm. The fault alarm indicator will FLASH and the AL2 fault code is shown on the upper display after the "Alarm Codes" key is pressed.
P016 is the setpoint for the low water temperature alarm. By displaying P016, the GSC+P indicates a low water temperature alarm fault.
AL3 Alarm for Low Engine Oil Pressure - When the engine oil pressure decreases to within 34 kPa (5 psi) of Setpoint P013 or P014, the GSC+P issues an alarm for the low engine oil pressure. The fault alarm indicator will FLASH and the "AL3" fault code is shown on the upper display after the "Alarm Codes" key is pressed.
P013 is the setpoint for low oil pressure shutdown at engine rated speed. If the oil pressure falls below this setpoint while the engine is at rated speed, the GSC+P will declare a low engine oil pressure fault. When the setpoint is reached, the dedicated shutdown indicator for low oil pressure flashes and the engine is shut down.
P014 is the setpoint for low oil pressure shutdown at idle speed. While the engine is at idle speed, Setpoint P014 tells the GSC+P when to declare a low oil pressure shutdown fault. When the setpoint is reached, the dedicated shutdown indicator for low oil pressure FLASHES and the engine is shutdown.
AL4 Fault Detected By The Engine ECM - The AL4 fault occurs when the Electronic Control Module (ECM) for the engine detects an alarm fault or a shutdown fault. The engine ECM tells the GSC+P whether the AL4 fault is an alarm fault or a shutdown fault. This indication includes faults that include derating of the engine. When the engine ECM is used in applications with generator sets, the engine ECM is programmed in the factory NOT to derate. The occurrence of an AL4 fault code could mean that the engine ECM is not programmed correctly. For the particular engine, refer to the Troubleshooting Service Module. The AL4 fault (P023) is disabled on MUI engines and gas engines.
When the fault is programmed as a shutdown fault, the fault shutdown indicator will FLASH and the "AL4" fault code is immediately shown on the upper display.
When the fault is programmed as an alarm fault, the fault alarm indicator will FLASH and the AL4 fault code is shown on the upper display after the alarm codes key is pressed.
AL5 Low Engine Coolant Level Fault - When the engine coolant level drops below the probe of the coolant loss sensor for ten seconds, the GSC+P issues a low coolant level warning (AL5). The GSC+P can be programmed (P006) to treat a low coolant level warning as an alarm or a shutdown. The fault can be disabled (P005). The GSC+P can be programmed to light one of the spare fault indicators when this fault occurs. The spare fault indicators are located on the front of the GSC+P.
When the fault is programmed as a shutdown fault, the fault shutdown indicator will FLASH and the AL5 fault code is immediately shown on the upper display.
When the fault is programmed as an alarm fault, the fault alarm indicator will FLASH and the "AL5" fault code is shown on the upper display after the "Alarm Codes" key is pressed.
AL6 High Engine Oil Temperature Fault - When the engine oil temperature rises to within 6 °C (11 °F) setpoint P026, the GSC+P issues a high engine oil temperature fault. The GSC+P can be programmed (P027) to treat this fault as an alarm, a shutdown, or the fault can be disabled (P025). When this fault occurs, the GSC+P can be programmed to light one of the spare fault indicators that is located on the GSC+P. The programmable setpoints are SP17, SP18 and SP19.
When the fault is programmed as a shutdown fault, the fault shutdown indicator will FLASH and the "AL6" fault code is immediately shown on the upper display.
When the fault is programmed as an alarm fault, the fault alarm indicator will FLASH and the "AL6" fault is shown on the upper display after the "Alarm Codes" key is pressed.
AL7 Generator Over Voltage Fault (protective relaying function) - When the line to line voltage between any two phases of the generator rises above the P102 setpoint or the P105 setpoint, the GSC+P issues an overvoltage fault. The GSC+P can be programmed to enable this fault or disable this fault as an alarm, a shutdown, or an alarm and a shutdown. The setpoints for the overvoltage fault are P101 and P104. The fault can be programmed with a time delay from 0 to 120 seconds. These setpoints are P103 and P106. The fault threshold can be adjusted from 100 percent to 125 percent of the nameplate voltage for the generator (P028. The setpoints for the fault threshold are P102 and P105.
When the fault is enabled as both an alarm fault and a shutdown fault, the fault thresholds and time delays can be programmed independently to allow the alarm fault to serve as an early warning for the shutdown fault.
When the fault is programmed as a shutdown fault, the fault shutdown indicator will FLASH and the AL7 fault code is immediately shown on the upper display.
When the fault is programmed as an alarm fault, the fault alarm indicator will FLASH and the AL7 fault code is shown on the upper display after the "Alarm Codes" key is pressed.
Note: If the AC offset adjustment OP10 has been performed, then the adjusted voltages are NOT used for determining the fault thresholds for protective relaying functions. The values that have not been adjusted for AC voltage are still determined by the GSC+P (but not shown), and the values will be used instead of the displayed values.
AL8 Generator Under Voltage Fault (protective relaying function) - When the line to line voltage that is between any two phases of the generator drops below Setpoint P108 or Setpoint P111, the GSC+P issues an under voltage fault. The GSC+P can be programmed to enable or disable the under voltage fault as an alarm, a shutdown, or an alarm and a shutdown. The setpoints for the under voltage fault are P107and P110. The fault can be programmed with a time delay from 0 to 120 seconds. The options with the time delay are P109 and P112. The fault threshold can be adjusted from 60 percent to 100 percent of the nameplate voltage (P028). The setpoints that are used for the fault threshold are P108 and P111.
When the fault is enabled as an alarm fault and a shutdown fault, the fault thresholds and time delays can be independently programmed. The independent programming allows the alarm fault to serve as an early warning to the shutdown fault.
When the fault is programmed as a shutdown fault, the fault shutdown indicator will FLASH and the AL8 fault code is immediately shown on the upper display.
When the fault is programmed as alarm fault, the fault alarm indicator will FLASH and the AL8 fault code is shown on the upper display after the "Alarm Codes" key is pressed.
Note: The AL8 fault is disabled when the ECS is in the STOP/COOLDOWN position.
Note: If the AC offset adjustment (OP10) has been performed, then the adjusted voltages are NOT used for determining the fault thresholds for protective relaying functions. The values that are not adjusted for the AC voltage are still determined by the GSC+P (but not shown), and will be used instead of the displayed values.
AL9 Generator Over Frequency Fault (protective relaying function) - When the generator frequency rises above the P113 or the P117setpoints, the GSC+P issues an overfrequency fault. The GSC+P can be programmed (P113 and P116) to enable or to disable this fault as an alarm, a shutdown, or both. The fault can be programmed (P115 and P118) with a time delay from 0 to 120 seconds. The fault threshold (P114 and P117) can be adjusted from 60 to 72 Hz (for 50 Hz applications, 50 to 60 Hz).
When the fault is enabled as both an alarm fault and a shutdown fault, the fault thresholds and time delays can be programmed independently to allow the alarm fault to serve as an early warning for the shutdown fault.
When the fault is programmed as a shutdown fault, the fault shutdown indicator will FLASH and the AL9 fault code is immediately shown on the upper display.
When the fault is programmed as an alarm fault, the fault shutdown indicator will FLASH and the AL9 fault code is shown on the upper display after the "Alarm Codes" key is pressed.
Note: The frequency shown on the GSC+P will FLASH when the generator frequency is greater than 70 Hz or equal to 70 Hz.
AL10 Generator Under Frequency Fault (protected relaying function) - When the generator frequency drops below the P120 or the P123 setpoints, the GSC+P issues an underfrequency fault. The GSC+P can be programmed (P119 and P122) to enable this fault or to disable this fault as an alarm, a shutdown or both. The fault can also be programmed (P121 and P124) with a time delay from 0 to 120 seconds. The fault threshold (P120and P123) can be adjusted from 36Hz to 60 Hz (for 50 Hz applications, 30 to 50 Hz).
When the fault is enabled as both an alarm fault and a shutdown fault, the fault thresholds and time delays can be programmed independently to allow the alarm fault to serve as an early warning for the shutdown fault.
When the fault is programmed as a shutdown fault, the fault shutdown indicator will FLASH and the AL10 fault code is immediately shown on the upper display.
When the fault is programmed as an alarm fault, the fault alarm indicator will FLASH and the AL10 fault code is shown on the upper display after the "Alarm Codes" key is pressed.
Note: The AL10 fault is disabled when the ECS is in the STOP/COOLDOWN position.
AL11 Generator Reverse Power Fault (protective relaying function) - When reverse power rises above the P126 setpoint, the GSC+P issues a reverse power fault. The GSC+P can be programmed (P125) to enable this fault or to disable this fault as a shutdown. In addition, the fault can be programmed (P127) with a time delay from 0 to 30 seconds. The fault threshold (P126) can be adjusted from 0 to 20 percent of the nameplate power (P030).
When the fault is programmed as a shutdown fault, the fault shutdown indicator will FLASH and the AL11 fault code is immediately shown on the upper display.
AL12 Generator Phase Over Current Fault (protective relaying function) - When any current rises above the P129 or the P134 setpoints, the GSC+P issues a phase over current fault. The GSC+P can be programmed (P128, P133) to enable or disable this fault as an alarm, a shutdown or both. The fault can also be programmed (P130 and P135) with a time delay from 0 to 250 seconds. The fault threshold (P129and P134) can be adjusted from 100 percent to 160 percent of the nameplate current (P029).
When the fault is enabled as both an alarm fault and a shutdown fault, the fault thresholds and time delays can be programmed independently to allow the alarm fault to serve as an early warning for the shutdown fault.
When the fault is programmed as a shutdown fault, the fault shutdown indicator will FLASH and the AL12 fault code is immediately shown on the upper display.
When the fault is programmed as an alarm fault, the fault alarm indicator will FLASH and the AL12 fault code is shown on the upper display after the "Alarm Codes" key is pressed.
AL13 Generator Total Over Current Fault (protective relaying function) - When generator total current (sum of three phases) rises above the P131 or P136 setpoints, the GSC+P issues a total over current fault. The GSC+P can be programmed (P128 and P133) to enable or to disable this fault as an alarm fault, a shutdown fault or both. In addition, the fault can be programmed (P132 and P137) with a time delay from 0 to 250 seconds. The fault threshold (P131 and P136) can be adjusted from 100 percent to 160 percent of three times the nameplate current rating (P029).
When the fault is enabled both as an alarm and a shutdown fault, the fault thresholds and time delays can be programmed independently to allow the alarm fault to serve as an early warning for the shutdown fault.
When the fault is programmed as a shutdown fault, the fault shutdown indicator will FLASH and the AL13 fault code is immediately shown on the upper display.
When the fault is programmed as an alarm fault, the fault alarm indicator will FLASH and the AL13 fault code is shown on the upper display after the "Alarm Codes" key is pressed.
AL14 Phase A No Voltage Input Fault (protective relaying function) - When the phase A voltage is not being received at the GSC+P input (GSC+P connector contact 10), the GSC+P issues a phase A no voltage input fault. The phase A voltage input is needed to accurately measure the generator output. The accuracy of some power metering functions and AC frequency measurement may be reduced. The GSC+P automatically treats a lost voltage input on phase A as an alarm fault. This response is not programmable.
When this fault occurs, the fault alarm indicator will FLASH and the AL14 fault code is shown on the upper display after the "Alarm Codes" key is pressed.
AL15 GSC+P Configuration Error - The GSC+P checks the relationship between the frequency of the generator output voltage and the engine speed. This relationship is shown in the formula below.
frequency (hertz) = (number of generator poles X rpm) / 120
The GSC+P automatically treats a configuration error as an alarm fault. This response is not programmable. This fault is corrected by programming the proper values into setpoints P009 (number of ring gear teeth) and P033 (number of generator poles).
When this fault occurs, the fault alarm indicator will FLASH and the AL15 fault code is shown on the upper display after the "Alarm Codes" key is pressed.
Note: If setpoint P033 (number of generator poles) is set to 0, the AL15 fault is disabled.
Paralleling Alarms
Paralleling Alarms are always treated as fault alarms and will not shut down the engine.
Synchronization may be halted, depending upon the fault. With one exception, paralleling alarms are issued only when the GSC+P is in Synchronization mode. The only paralleling alarm that will be active in Normal mode is AL16 Incorrect Phase Sequence. If this alarm is active in Normal mode, the alarm will be displayed when the "AL CODES" key is pressed, in the same manner as other fault alarms.
Paralleling alarms are detected and annunciated only if synchronization is enabled by programming the Synchronization Enabled setpoint, P301, with a non-zero value.
AL16 Incorrect Phase Sequence - This fault occurs whenever any synchronization function is in progress, and the GSC+P verifies that the generator and the bus have a phase sequence mismatch. The incorrect Phase Sequence alarm is immediately made active, and synchronization is halted. In this case, the alarm is latched until the synchronization request is removed. If the request was made locally using the SMS, then the SMS must be moved to the OFF position to CLEAR the alarm. If the phase sequence mismatch is detected immediately following closure to a dead bus, but no synchronization function is in progress, the "Incorrect Phase Sequence" alarm is made active but is not latched. In this case, if the phase sequence mismatch condition is not present, the alarm will be removed.
AL17 Improper Generator Or Bus Voltage - This fault occurs whenever the generator voltage, bus voltage, or both are incorrect for synchronization. The alarm is generated only if synchronization is enabled and synchronization request has been made. The conditions that may cause an "Improper Generator Alarm" or "Bus Voltage Alarm" are listed below.
- The Bus voltage is too low for synchronization.
- The Generator voltage is too low for synchronization.
- The Generator voltage and the Bus voltage are out of tolerance.
The specific conditions tested depend on the synchronization request and on setpoint values. Setpoint P303 enables or disables generator voltage or bus voltage checking during automatic synchronization. Setpoint P304 determines the mazimum acceptable difference in voltage between the bus voltage and the generator voltage.
This alarm will prevent frequency control and and breaker closure while the alarm is active, but will not halt synchronization. If the condition causing the alarm is removed while synchronization is in progress, then the alarm will be removed and the GSC+P will proceed with synchronization.
If the Improper Generator Alarm or the Bus Voltage Alarm is active when synchronizationis halted due to a synchronizer Time-out Alarm, the alarm is latched until the synchronization request is removed. In this case, if the request was made locally using the SMS, then the SMS must be moved to the OFF position to CLEAR the alarm. If the request was made remotely using a Customer Communication Module (CCM), then the CCM must send a Generator Synchronizer Control command (with a value of OFF) to CLEAR the alarm.
AL18 Synchronizer Time-out Alarm - This fault occurs whenever the GSC+P is unable to complete Automatic Synchronization or Dead Bus Parallel after a programmed amount of time. For the purposes of this alarm, Automatic Synchronization /Dead Bus Parallel is considered complete after breaker closure has been verified.
This alarm has two time-out thresholds, Synchronization Time Warning and Maximum Synchonization Time fault. Synchronization may be halted, depending on the time-out threshold that has been exceeded.
Timing for this alarm is started when Automatic Synchronization is requested, and the Dead Bus On-Time Delay (if the bus is dead) has completed.
Note: If the GSC+P closes the breaker, and a fault occurs that causes the breaker to open within 15 seconds, the GSC+P will lock out all synchronization functions until the SMS is turned to another position. If the breaker opens after 15 seconds, the GSC+P will reattempt the requested synchronization function.
Synchronization Time Warning
If the GSC+P is unable to complete Automatic Synchronization or Dead Bus Paralleling during the time specified in the Synchronization Time Warning setpoint, the GSC+P will activate the AL18 Synchronizer Time-out Alarm but continue synchronization. If synchronization is completed before the Maximum Synchronization Time fault setpoint has expired, the alarm will be deactivated.
Maximum Synchronization Time Fault
If the GSC+P is unable to complete Automatic Synchronization or Dead Bus Parallel during the time specified in the Maximum Synchronization Time-out Fault setpoint, the GSC+P will activate AL18 Synchronizer Time-out Alarm and halt synchronization. In this case, the alarm is latched until the synchronization request is removed. If the request was made locally using the SMS, then the SMS must be moved to the OFF position to CLEAR the alarm. If the request was made remotely by a CCM, then the CCM must send a Generator Synchonizer Control command (with a value of OFF) to CLEAR the alarm.