# JASC 2424: AC Regulator

- Type: JASC system/component code (FAA)
- ATA chapter: 24 Electrical Power
- Title in the code table: AC REGULATOR
- Service difficulty reports: 480
- FAA code table: https://www.faa.gov/sites/faa.gov/files/JASC_Code.pdf#page=20
- Page: https://openairdocs.org/jasc/2424

## What it covers

The component that regulates the AC voltage from the alternator-generator to maintain a set voltage output for the using systems (i.e., generator control unit).

## Service difficulty reports (480, newest 50)

- [SDR TIMA20230224002](https://openairdocs.org/sdr/TIMA20230224002), Feb 19, 2023: Beech B99. NONE. NONE. STARTED TRAINING FLIGHT, DID TRIM RUNAWAY, STEEP TURNS, CRUISE STALL, APPROACH TO LAND STALL. ON APPROACH TO LAND STALL  (N216CS)
- [SDR HALA2023021000021](https://openairdocs.org/sdr/HALA2023021000021), Feb 9, 2023: Airbus A330243. UNKNOWN. UNKNOWN. ETOPS-ELEC APU GEN FAULT. REMOVED AND REPLACED APU GENERATOR IAW A330 AMM 24-23-51. OPS CHECK GOOD. NO FAULT NOTED. NO L (N388HA)
- [SDR HALA2023011800008](https://openairdocs.org/sdr/HALA2023011800008), Jan 17, 2023: Airbus A330243. APU. SHUTDOWN. APU AUTO SHUTDOWN ON VERIFICATION FLIGHT. STILL IN WORK (N381HA)
- [SDR HALA2022112800301](https://openairdocs.org/sdr/HALA2022112800301), Nov 25, 2022: Airbus A330243. GENERATOR. LEAKING. ETOPS- DIRYT SOCKS SMELL ON DECENT AND WHEN AT THE GATE WITH APU ON IN SEATTLE. INSPECTED #1 AND #2 ENGINE, RAN ENGINES, (N384HA)
- [SDR ENHA202290240002](https://openairdocs.org/sdr/ENHA202290240002), Aug 19, 2022: Cessna 207A. REGULATOR. ABNORMAL. DURING FLIGHT RADIO AND ADSB STOPPED WORKING WHILE IN FLIGHT. MAINTENANCE INSPECTED AIRCRAFT AND REPLACED VOLTAGE REGULA (N9651M)
- [SDR HALA2022062700117](https://openairdocs.org/sdr/HALA2022062700117), Jun 24, 2022: Airbus A330243. NONE. NONE. ETOPS - FOUND APU GENERATOR LEAKING OIL // REMOVED AND REPLACED APU GEN. LEAKED AND OPS CHECKED GOOD. REF A330 AMM 24-23 (N383HA)
- [SDR HALA2022061600114](https://openairdocs.org/sdr/HALA2022061600114), Jun 15, 2022: Airbus A330243. NONE. NONE. ETOPS - APU GEN FAULT // REMOVED AND REPLACED APU GEN PER AMM 24-23-51-400-801-A. OPS SAME. REMOVED AND REPACED GAPCU PE (N382HA)
- [SDR HALA2022052300101](https://openairdocs.org/sdr/HALA2022052300101), May 21, 2022: Airbus A330243. NONE. NONE. ETOPS - ELEC APU GEN FAULT ECAM // PERFORMED BITE OF EPGS REF. AMM 24-41-00-740-801-A. FAULT CODE 242317 WAS CAPTURED. C (N382HA)
- [SDR HALA2022040600085](https://openairdocs.org/sdr/HALA2022040600085), Apr 5, 2022: Airbus A330243. NONE. NONE. ETOPS - ECAM APU GEN FAULT AFTER APU START UP ON PDC // TROUBLESHOT PER TSM 24-20-51-810-804-A. NEED TO REPLACE GLC-APU  (N361HA)
- [SDR HALA2022012400021](https://openairdocs.org/sdr/HALA2022012400021), Jan 23, 2022: Airbus A330243. GENERATOR. INOPERATIVE. ETOPS - APU GEN FAULT // ACCOMPLISHED TSM 24-20-81-810-905-A. BITE TEST OF EPGSM TEST PASSED FOR GAPCU. TSM NEXT STEP IS (N395HA)
- [SDR HALA2022011900019](https://openairdocs.org/sdr/HALA2022011900019), Jan 19, 2022: Airbus A330243. GENERATOR. DEFECTIVE. ETOPS - APU GEN FAULT BEFORE ENGINE START // PERFORMED FIM 24-20-00-810-985-A. REMOVED AND REPLACED APU GEN PER AMM UP T (N393HA)
- [SDR YENA2022011800018](https://openairdocs.org/sdr/YENA2022011800018), Jan 9, 2022: Airbus A321271N. GENERATOR. FAILED. FLT # 20, LHR-JFK. NO POWER FROM APU GENERATOR; R/R APU GENERATOR REF AMM 24-23-51. OPS CHECK NML. OK FOR SVC (N4058J)
- [SDR HALA2021092800126](https://openairdocs.org/sdr/HALA2021092800126), Sep 27, 2021: Airbus A330243. GENERATOR. DEFECTIVE. ETOPS - APU GENERATOR FAULT DURING MAINTENANCE NO POWER FROM GEN FAULT. // REMOVED AND REPLACED GAPCU PER AMM 24-41-34 F
- [SDR UIEA2021020100175](https://openairdocs.org/sdr/UIEA2021020100175), Feb 1, 2021: Boeing 76731K. GCU. FAILED. DUE TO PREVIOUS FAULT CT LOOP FAIL, CHANGE APU GCU. R & R APU GCU IAW AMM 24-22-01, OPS CHECK OK. (N1487A)
- [SDR HALA2020091430182](https://openairdocs.org/sdr/HALA2020091430182), Sep 11, 2020: Airbus A330243. GENERATOR. OUT OF LIMITS. DURING SERVICE CHECK APU GEN FAULT LIGHT NO OUTPUT POWER FROM APU, RPTD BY CHACON. GENERATOR APU, OFF 33-2423-9-0001 043 (N379HA)
- [SDR HYIA202009109002](https://openairdocs.org/sdr/HYIA202009109002), Sep 8, 2020: Cessna 402C. VOLT REGULATOR. DAMAGED. THE PILOT REPORTED A DUAL ALTERNATOR FAILURE AFTER TAKE-OFF. MAINTENANCE INSPECTED AND FOUND THE RIGHT HAND VOLTAGE REGU (N890CA)
- [SDR UIEA2020070901508](https://openairdocs.org/sdr/UIEA2020070901508), Jul 7, 2020: Boeing 76731K. GCU. FAILED. LT AC BUS FAILED DURING POWER TRANSFER WHILE SHUTTING OFF ENGINES PERFORMED BITE TEST OF BPCU. LT GCU FAIL AND BTB SW/WI (N1489A)
- [SDR UIEA2020062901453](https://openairdocs.org/sdr/UIEA2020062901453), Jun 29, 2020: Boeing 76731A. GCU. FAULTY. R GEN OFF, SERVICED RT ENG IDG IAW AMM 12-13-03. ACCOMPLISHED BPCU TEST, FOUND GCU FAULT. REMOVED AND REPLACED GCU IAW A (N662GT)
- [SDR P5CA2020061500191](https://openairdocs.org/sdr/P5CA2020061500191), Jun 13, 2020: Boeing 7673JHF. GCU. MALFUNCTIONED. AFTER ENG START L GEN OFF EICAS ANNUNCIATED. RESET L GEN CONTROL PER NON-NORMAL, OPS NORMAL REMAINDER OF FLIGHT. FOUND B (N644GT)
- [SDR AXSA2020061200001](https://openairdocs.org/sdr/AXSA2020061200001), Jun 11, 2020: Emb EMB110P1. CONTROL UNIT. DEFECTIVE. LOST BOTH GENERATORS IN FLIGHT (N119WA)
- [SDR UIEA2020060101149](https://openairdocs.org/sdr/UIEA2020060101149), May 28, 2020: Boeing 767375. GCU. MALFUNCTIONED. RIGHT IDG INOPERATIVE. TRANSFER TO MDDR #128942 IAW MEL 24-00-01-01 CAT B DUE DATE 31-MAY-2020 LOG PAGE 1138658. REMOVED (N649GT)
- [SDR UIEA2020060101163](https://openairdocs.org/sdr/UIEA2020060101163), May 27, 2020: Boeing 767383. GCU. MALFUNCTIONED. LEFT UTILITY BUS INOPERATIVE. TRANSFERRED TO MDDR 128861 MEL 24-51-01, CAT C, DUE 04 JUNE 20, LOG PAGE 1143636. REMOVED  (N1511A)
- [SDR FDEA2020052211014](https://openairdocs.org/sdr/FDEA2020052211014), May 21, 2020: Airbus A300F4605R. GCU. MALFUNCTIONED. PDIS 689 24-20 1465 20MAY20 GENERATOR #2 FAULT @ CLIMB FROM FL 300 TO FL 330. TRIED RESET GENERATOR #2 WOULD NOT RESET . (N689FE)
- [SDR UIEA2020042700827](https://openairdocs.org/sdr/UIEA2020042700827), Apr 24, 2020: Boeing 767306. GCU. FAULTY. R AC BUS EICAS MSG DURING DESCENT&NBSP;(<P>REPLACED RH GEN GCU. IAW AMM 24-22-02. OPS CHKS GOOD.</P>) (N1409A)
- [SDR UIEA2020042400824](https://openairdocs.org/sdr/UIEA2020042400824), Apr 24, 2020: Boeing 767306. GCU. MALFUNCTIONED. R GEN TRIPPED OFF, RAN QRH, RECOVERED R GEN, BUT R UTILITY WOULD NOT COME ON LINE. POSITION 13000 FT MSL30 NM FROM ILN.( (N1409A)
- [SDR VNAA2020040241102](https://openairdocs.org/sdr/VNAA2020040241102), Mar 31, 2020: Cndair CL6002D24. GCU. MALFUNCTIONED. DURING CRUISE TO MKE THE CAPT REPORTED A IDG 1, GEN 1, AC BUS 1 MAGENTA FAULT. HE DIVERTED TO DAY PER OUR REQUEST. MX HA (N608NN)
- [SDR UIEA2020031700452](https://openairdocs.org/sdr/UIEA2020031700452), Mar 14, 2020: Boeing 76731A. GCU. MALFUNCTIONED. INFO ONLY, R GEN CAME OFFLINE BRIEFLY &AMP; RESET W/O ISSUE.(<P>ACCOMPLISHED BPCU BITE TEST. NO MESSAGES NOTED, REMOVED  (N662GT)
- [SDR CALA2020032000641](https://openairdocs.org/sdr/CALA2020032000641), Mar 13, 2020: Boeing 777300ER. GCU. FAULTY. MOMENTARY LOSS OF ALL ELECTRICAL COMPONENTS PWR CYCLED TWICE SUSPECT GCU 2, REF FIM 24-13-00-810-809, SN5170 HAS FAULT H (N2748U)
- [SDR CALA2020032000640](https://openairdocs.org/sdr/CALA2020032000640), Mar 13, 2020: Boeing 777300ER. GCU. FAULTY. THE TOMC CONTROLLER AND SENIOR MANAGER CONCUR THAT THE AIRCRAFT CAN BE RELEASED BACK TO SERVICE AFTER EXPERIENCING A DIV (N2748U)
- [SDR JIKA20200317301](https://openairdocs.org/sdr/JIKA20200317301), Mar 13, 2020: Beech C99. GCU. OUT OF ADJUST. ENROUTE TO PHX FROM OLS WHEN CREW WAS ADVISED TO HOLD FOR WEATHER AROUND THE SAMETIME THE AIRCRAFT LOST SEVERAL INSTRUME (N225BH)
- [SDR UIEA2020031300440](https://openairdocs.org/sdr/UIEA2020031300440), Mar 12, 2020: Boeing 7673S1. GCU. MALFUNCTIONED. APU GENERATOR DROPPED OFF LINE, APU RUNS OK (ELECTRIC INOP), BPCU FAULTS GEN TRIP AND GEN.(<P>DEFERRED APU GENERATOR INO (N640GT)
- [SDR G1IA2020031300000](https://openairdocs.org/sdr/G1IA2020031300000), Mar 10, 2020: Beech B200. GCU. CONTAMINATED. FAR 1135.415 REPORT. PILOT REPORTS "LH GENERATOR DROPPED OFFLINE CAUSING A MASTER CAUTION. TRIED ONE RESET, BOTH VOLTMET (N351SA)
- [SDR UIEA2020010800035](https://openairdocs.org/sdr/UIEA2020010800035), Jan 5, 2020: Boeing 7673S1. GCU. MALFUNCTIONED. REPEATS OF RT GENERATOR DISCONNECT ON RT ENGINE START.(<P>REMOVED AND REPLACED RIGHT GENERATOR CONTROL UNIT IAW B767 AMM (N640GT)
- [SDR UIEA2019110505860](https://openairdocs.org/sdr/UIEA2019110505860), Nov 5, 2019: Boeing 76731K. GCU. MALFUNCTIONED. MOMENTARY GEN DRIVE EICAS AFTER START.(<P>REMOVED AND REPLACED L GEN CONTROL UNIT IAW AMM 24-22-02, OPS CHECK GOOD AND N (N1373A)
- [SDR QXEA2019093000373](https://openairdocs.org/sdr/QXEA2019093000373), Sep 27, 2019: Bombdr DHC8402. GCU. MALFUNCTIONED. #1 AC GEN CAUTION LIGHT ILLUMINATED BEGINNING INTERMITTENTLY AT APPROXIMATELY 20,000FT LIGHT EVENTUALLY REMIANED ILLUMIA (N427QX)
- [SDR AALA201909259001](https://openairdocs.org/sdr/AALA201909259001), Sep 23, 2019: Emb ERJ190100IGW. GCU. FAILED. AIRCRAFT WAS GROUNDED: PILOT REPORTS DURING CRUISE "IDG 1 OFF BUS" FORCED ELEC EMERGENCY CONDITION. APU STARTED SUCCESSF (N956UW)
- [SDR AALA201909179006](https://openairdocs.org/sdr/AALA201909179006), Sep 16, 2019: Airbus A321211. GCU. FAILED. AIRCRAFT WAS GROUNDED: FLIGHT DIVERTED TO BNA ON ACCOUNT OF APU SHUT DOWN AND NUMBER TWO GENERATOR ON PLACARD. AN EMERGE (N165US)
- [SDR FDEA201909062113](https://openairdocs.org/sdr/FDEA201909062113), Sep 6, 2019: Doug MD11F. RELAY. FAULTY. TEST FLIGHT - WHEN CHECKING THE ADG, YOU PULL L EMER AC BUS C/B (UPPER MAIN B-14) TRIPPING THE EMER PWR SWITCH FROM ARM  (N590FE)
- [SDR Q2SA20190702423](https://openairdocs.org/sdr/Q2SA20190702423), Jul 2, 2019: Boeing 73783N. GCU. MALFUNCTIONED. AIRCRAFT GROUNDED. DURING THE "BEFORE START CHECKLIST", THE APU GEN TRIPPED OFF AND A STRONG ELECTRICAL SMELL FILLED THE (N5153A)
- [SDR FDEA201903010529](https://openairdocs.org/sdr/FDEA201903010529), Mar 1, 2019: Airbus A300F4605R. GCU. INOPERATIVE. PDIS 731 24-20 2134 01MAR19 CLE FACT U LOGPAGES:2733993 DURING CLIMBOUT FROM KPIT @ 14000' GEN 1 FAULTED. ATTEMPTED TO R (N731FD)
- [SDR QXEA2019021100069](https://openairdocs.org/sdr/QXEA2019021100069), Feb 10, 2019: Bombdr DHC8402. GCU. MALFUNCTIONED. A/C GEN CAUTION ILLUMINATED FLICKERED ABOUT 10 TIMES BEFORE STAYING ON. REMOVED FROM SERVICE. INTERROGATED CDS AND NO FA (N427QX)
- [SDR UIEA2019011500091](https://openairdocs.org/sdr/UIEA2019011500091), Jan 15, 2019: Boeing 76731K. GCU. MALFUNCTIONED. LEFT ENG GEN OFF LIGHT&NBSP;(<P>TRANSFERRED TO MDDR # 105940 AS PER MEL 24-00-01-01 CAT B&NBSP;</P><P>LOG PAGE 706715&NB (N1487A)
- [SDR SIMA20181212004](https://openairdocs.org/sdr/SIMA20181212004), Dec 12, 2018: Emb EMB145LR. GCU. FAILED. GEN1-4 OFF BUS EICAS MESSAGE DISPLAYED INTERMITTENTLY THEN RETURNED TO GEN 1 OFF BUS WHICH IS NORMAL CONDITION DUE TO CU (N623AE)
- [SDR ASAA2018121127357](https://openairdocs.org/sdr/ASAA2018121127357), Dec 11, 2018: Boeing 737990ER. GCU. FAULTY. NR 1 TRANSFER BUS OFF LIGHT ILLUMINATED AT CRUISE FL230. ACCOMPLISHED QRH, BUS WOULD NOT RESET, TRANSFERRED TO APU BUS.  (N479AS)
- [SDR AALA2018121809002](https://openairdocs.org/sdr/AALA2018121809002), Dec 8, 2018: Boeing 777223. CIRCUIT BREAKER. FAULTY. THE AIRCRAFT WAS GROUNDED. AC DIVERTED TO ORD ON ACCOUNT 7 TIMES DURING DESCENT FROM 18,000 FEET THROUGHOUT TOUCHDOWN -  (N772AN)
- [SDR AALA201812039014](https://openairdocs.org/sdr/AALA201812039014), Dec 2, 2018: Emb ERJ190100IGW. GCU. FAILED. FLT 1869 EN-ROUTE MCI - PHL. THE AIRCRAFT WAS GROUNDED. IDG 2 OFF BUS CAUTION MSG OCCURRED IN FLIGHT COMPLIED WITH QRH M (N959UW)
- [SDR FDEA201812013411](https://openairdocs.org/sdr/FDEA201812013411), Dec 1, 2018: Airbus A300F4605R. GCU. MALFUNCTIONED. OPERATING UNDER MEL 49-33-12 (NO APU GEN AVAILABLE) DURING TAKEOFF AT V1 FO PFD FLICKERED, ALT FLAT. AT APPROXIMATELY 10 (N661FE)
- [SDR ASAA2018112727132](https://openairdocs.org/sdr/ASAA2018112727132), Nov 27, 2018: Boeing 737990ER. GCU. FAILED. TRANSFER OF POWER AFTER LANDING TO APU NR 1 TRANSFER BUS OFF LIGHT CAME ON. GROUNDED - YES. ACCOMPLISHED TRANSFER BUS OF (N479AS)
- [SDR CALA2018111902403](https://openairdocs.org/sdr/CALA2018111902403), Nov 19, 2018: Airbus A320232. WIRE. ARCED. MULTPLE SYSTEMS POWERED BY AC BUS 1 FAILED DURING FLIGHT RELATED TO AC BUS 1. UPDATED MAA CODE FIX USING VENDOR MAA SCRE (N439UA)
- [SDR CALA2018101502120](https://openairdocs.org/sdr/CALA2018101502120), Oct 15, 2018: Boeing 75733N. GCU. INOPERATIVE. EICAS WENT BLANK AFTER T/O THEN R HYD ELEC PUMP AUTOTHROTTLE DISC FOUND C/B OPEN/POPPED, P31 L GEN PWR PNL. CB 115 VAC B (N77871)

All 480: https://openairdocs.org/jasc/2424/reports.md

## Other codes in chapter 24

- [JASC 2400](https://openairdocs.org/jasc/2400): Electrical Power System (1,186 reports)
- [JASC 2410](https://openairdocs.org/jasc/2410): Alternator-Generator Drive (891 reports)
- [JASC 2420](https://openairdocs.org/jasc/2420): AC Generation System (1,302 reports)
- [JASC 2421](https://openairdocs.org/jasc/2421): AC Generator-Alternator (4,273 reports)
- [JASC 2422](https://openairdocs.org/jasc/2422): AC Inverter (557 reports)
- [JASC 2423](https://openairdocs.org/jasc/2423): Phase Adapter (15 reports)
- [JASC 2425](https://openairdocs.org/jasc/2425): AC Indicating System (137 reports)
- [JASC 2430](https://openairdocs.org/jasc/2430): DC Generating System (1,121 reports)
- [JASC 2431](https://openairdocs.org/jasc/2431): Battery Overheat Warning System (82 reports)
- [JASC 2432](https://openairdocs.org/jasc/2432): Battery/Charger System (2,249 reports)
- [JASC 2433](https://openairdocs.org/jasc/2433): DC Rectifier/Converter (197 reports)
- [JASC 2434](https://openairdocs.org/jasc/2434): DC Generator-Alternator (849 reports)
- [JASC 2435](https://openairdocs.org/jasc/2435): Starter-Generator (2,052 reports)
- [JASC 2436](https://openairdocs.org/jasc/2436): DC Regulator (313 reports)
- [JASC 2437](https://openairdocs.org/jasc/2437): DC Indicating System (98 reports)
- [JASC 2440](https://openairdocs.org/jasc/2440): External Power System (169 reports)
- [JASC 2450](https://openairdocs.org/jasc/2450): AC Power Distribution System (872 reports)
- [JASC 2460](https://openairdocs.org/jasc/2460): DC Power Distribution System (608 reports)
- [JASC 2497](https://openairdocs.org/jasc/2497): Electrical Power System Wiring (2,202 reports)

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