MuscleGrid Focus 6.2 kW (MG6500-48) — All Fault & Alarm Codes

01Fault 1: Bus boost fail

MG6500-48 (Focus 6.2 kW) FAULT CODE 1 — Bus boost fail. The inverter enters FAULT mode (steady red Fault LED, LCD shows 'Err 1'). Trigger: Grid soft-start begins but bus voltage does not reach the set value. Recovery: Restores after reaching set voltage for 15 s. In fault mode the unit auto-retries; after 6 failed restarts it stays in fault — power off fully (or wait 30 min) to restart. If it persists, escalate to service.

02Fault 2: Bus over voltage

MG6500-48 (Focus 6.2 kW) FAULT CODE 2 — Bus over voltage. The inverter enters FAULT mode (steady red Fault LED, LCD shows 'Err 2'). Trigger: Bus voltage higher than set value. Recovery: Restores after reaching set voltage for 15 s. In fault mode the unit auto-retries; after 6 failed restarts it stays in fault — power off fully (or wait 30 min) to restart. If it persists, escalate to service.

03Fault 3: Bus below voltage

MG6500-48 (Focus 6.2 kW) FAULT CODE 3 — Bus below voltage. The inverter enters FAULT mode (steady red Fault LED, LCD shows 'Err 3'). Trigger: Bus voltage lower than set value. Recovery: Cannot restore (service required). In fault mode the unit auto-retries; after 6 failed restarts it stays in fault — power off fully (or wait 30 min) to restart. If it persists, escalate to service.

04Fault 4: Battery over current

MG6500-48 (Focus 6.2 kW) FAULT CODE 4 — Battery over current. The inverter enters FAULT mode (steady red Fault LED, LCD shows 'Err 4'). Trigger: Battery current higher than set value. Recovery: Cannot restore (service required). In fault mode the unit auto-retries; after 6 failed restarts it stays in fault — power off fully (or wait 30 min) to restart. If it persists, escalate to service.

05Fault 5: System over temperature

MG6500-48 (Focus 6.2 kW) FAULT CODE 5 — System over temperature. The inverter enters FAULT mode (steady red Fault LED, LCD shows 'Err 5'). Trigger: PFC temperature higher than set value OR fan not connected. Recovery: Restores after temperature falls below set value and fan connected for 15 min. In fault mode the unit auto-retries; after 6 failed restarts it stays in fault — power off fully (or wait 30 min) to restart. If it persists, escalate to service.

06Fault 6: Battery over voltage

MG6500-48 (Focus 6.2 kW) FAULT CODE 6 — Battery over voltage. The inverter enters FAULT mode (steady red Fault LED, LCD shows 'Err 6'). Trigger: Battery voltage higher than set value. Recovery: Restores after reaching set voltage for 15 s. In fault mode the unit auto-retries; after 6 failed restarts it stays in fault — power off fully (or wait 30 min) to restart. If it persists, escalate to service.

07Fault 7: Bus soft start failed

MG6500-48 (Focus 6.2 kW) FAULT CODE 7 — Bus soft start failed. The inverter enters FAULT mode (steady red Fault LED, LCD shows 'Err 7'). Trigger: Battery soft-start begins but bus voltage not reached. Recovery: Restores after reaching set voltage for 15 s. In fault mode the unit auto-retries; after 6 failed restarts it stays in fault — power off fully (or wait 30 min) to restart. If it persists, escalate to service.

08Fault 8: Bus short circuit

MG6500-48 (Focus 6.2 kW) FAULT CODE 8 — Bus short circuit. The inverter enters FAULT mode (steady red Fault LED, LCD shows 'Err 8'). Trigger: Bus voltage lower than set value. Recovery: Cannot restore (service required). In fault mode the unit auto-retries; after 6 failed restarts it stays in fault — power off fully (or wait 30 min) to restart. If it persists, escalate to service.

09Fault 9: Inverter soft start failed

MG6500-48 (Focus 6.2 kW) FAULT CODE 9 — Inverter soft start failed. The inverter enters FAULT mode (steady red Fault LED, LCD shows 'Err 9'). Trigger: Inverter soft-start begins but inverter voltage not reached. Recovery: Restores after reaching set voltage for 15 s. In fault mode the unit auto-retries; after 6 failed restarts it stays in fault — power off fully (or wait 30 min) to restart. If it persists, escalate to service.

11Fault 11: Inverter under voltage

MG6500-48 (Focus 6.2 kW) FAULT CODE 11 — Inverter under voltage. The inverter enters FAULT mode (steady red Fault LED, LCD shows 'Err 11'). Trigger: Inverter voltage lower than set value in battery mode. Recovery: Restores after reaching set voltage for 15 s. In fault mode the unit auto-retries; after 6 failed restarts it stays in fault — power off fully (or wait 30 min) to restart. If it persists, escalate to service.

12Fault 12: Inverter short circuit

MG6500-48 (Focus 6.2 kW) FAULT CODE 12 — Inverter short circuit. The inverter enters FAULT mode (steady red Fault LED, LCD shows 'Err 12'). Trigger: Inverter voltage < set value AND current > set value. Recovery: Restores after reaching set value for 15 s. In fault mode the unit auto-retries; after 6 failed restarts it stays in fault — power off fully (or wait 30 min) to restart. If it persists, escalate to service.

13Fault 13: Inverter negative power

MG6500-48 (Focus 6.2 kW) FAULT CODE 13 — Inverter negative power. The inverter enters FAULT mode (steady red Fault LED, LCD shows 'Err 13'). Trigger: Inverter power negative and exceeds set value for a period. Recovery: Restores after reaching set value for 15 s. In fault mode the unit auto-retries; after 6 failed restarts it stays in fault — power off fully (or wait 30 min) to restart. If it persists, escalate to service.

14Fault 14: Over load

MG6500-48 (Focus 6.2 kW) FAULT CODE 14 — Over load. The inverter enters FAULT mode (steady red Fault LED, LCD shows 'Err 14'). Trigger: Load current higher than set value (continuous over-current 5 s, e.g. discharge over Program 61 limit). Recovery: Restores after reaching set value for 15 s. In fault mode the unit auto-retries; after 6 failed restarts it stays in fault — power off fully (or wait 30 min) to restart. If it persists, escalate to service.

17Fault 17: Program updating

MG6500-48 (Focus 6.2 kW) FAULT CODE 17 — Program updating. The inverter enters FAULT mode (steady red Fault LED, LCD shows 'Err 17'). Trigger: Inverter firmware updating / OTA in progress. Recovery: Restores after updating. In fault mode the unit auto-retries; after 6 failed restarts it stays in fault — power off fully (or wait 30 min) to restart. If it persists, escalate to service.

18Fault 18: PV reverse connection

MG6500-48 (Focus 6.2 kW) FAULT CODE 18 — PV reverse connection. The inverter enters FAULT mode (steady red Fault LED, LCD shows 'Err 18'). Trigger: PV array connected with reversed polarity. Recovery: Restores after connecting correctly for 15 s. In fault mode the unit auto-retries; after 6 failed restarts it stays in fault — power off fully (or wait 30 min) to restart. If it persists, escalate to service.

26Fault 26: BMS fault

MG6500-48 (Focus 6.2 kW) FAULT CODE 26 — BMS fault. The inverter enters FAULT mode (steady red Fault LED, LCD shows 'Err 26'). Trigger: Error code present in BMS message. Recovery: Restores after the BMS fault is resolved. In fault mode the unit auto-retries; after 6 failed restarts it stays in fault — power off fully (or wait 30 min) to restart. If it persists, escalate to service.

29Fault 29: Inverter load abnormal

MG6500-48 (Focus 6.2 kW) FAULT CODE 29 — Inverter load abnormal. The inverter enters FAULT mode (steady red Fault LED, LCD shows 'Err 29'). Trigger: Abnormal inverter load drives abnormal voltage. Recovery: Restores after voltage returns to normal for 15 s. In fault mode the unit auto-retries; after 6 failed restarts it stays in fault — power off fully (or wait 30 min) to restart. If it persists, escalate to service.

50Alarm 50: Battery open

MG6500-48 (Focus 6.2 kW) ALARM CODE 50 — Battery open. This is an ALARM, NOT a fault (red Fault LED flashes, LCD shows 'ALA 50', the inverter keeps running). Action: Alarm. Trigger: Battery disconnected for no more than 10 minutes. Recovery: Restores after battery reconnected and charging for 2 min.

51Alarm 51: Battery under voltage

MG6500-48 (Focus 6.2 kW) ALARM CODE 51 — Battery under voltage. This is an ALARM, NOT a fault (red Fault LED flashes, LCD shows 'ALA 51', the inverter keeps running). Action: Alarm; battery low-voltage shutdown / cannot power on. Trigger: Battery voltage lower than the BAU set value (Program 19). Recovery: Restores after battery voltage exceeds the BAU set value by 2 V.

52Alarm 52: Battery low voltage

MG6500-48 (Focus 6.2 kW) ALARM CODE 52 — Battery low voltage. This is an ALARM, NOT a fault (red Fault LED flashes, LCD shows 'ALA 52', the inverter keeps running). Action: Alarm. Trigger: Battery voltage lower than the BAL set value (Program 18). Recovery: Restores after battery voltage exceeds the BAL set value by 2 V.

53Alarm 53: Battery charge short circuit

MG6500-48 (Focus 6.2 kW) ALARM CODE 53 — Battery charge short circuit. This is an ALARM, NOT a fault (red Fault LED flashes, LCD shows 'ALA 53', the inverter keeps running). Action: Alarm; battery does not charge. Trigger: Battery voltage < 12 V while charging current exists. Recovery: Restores after max 1 min once the short circuit is eliminated.

56Alarm 56: BMS loss

MG6500-48 (Focus 6.2 kW) ALARM CODE 56 — BMS loss. This is an ALARM, NOT a fault (red Fault LED flashes, LCD shows 'ALA 56', the inverter keeps running). Action: Alarm. Trigger: Communication failure after BMS communication function (Program 44) is enabled. Recovery: Restores after BMS comms disabled or communication succeeds.

58Alarm 58: Fan error

MG6500-48 (Focus 6.2 kW) ALARM CODE 58 — Fan error. This is an ALARM, NOT a fault (red Fault LED flashes, LCD shows 'ALA 58', the inverter keeps running). Action: Alarm; fans run at full speed. Trigger: No fan-speed signal detected (fan rotating < 8 times in 2 s). Recovery: Restores after a fan-speed signal is detected.

59Alarm 59: EEPROM error

MG6500-48 (Focus 6.2 kW) ALARM CODE 59 — EEPROM error. This is an ALARM, NOT a fault (red Fault LED flashes, LCD shows 'ALA 59', the inverter keeps running). Action: Alarm. Trigger: EEPROM read/write exception. Recovery: Cannot restore (service required).

60Alarm 60: Overload

MG6500-48 (Focus 6.2 kW) ALARM CODE 60 — Overload. This is an ALARM, NOT a fault (red Fault LED flashes, LCD shows 'ALA 60', the inverter keeps running). Action: Alarm. Trigger: Mains current / battery discharge current / load power higher than rated value. Recovery: Restores after it falls below the rated value.

62Alarm 62: PV energy weak

MG6500-48 (Focus 6.2 kW) ALARM CODE 62 — PV energy weak. This is an ALARM, NOT a fault (red Fault LED flashes, LCD shows 'ALA 62', the inverter keeps running). Action: Alarm; PV output to load turned off but PV keeps charging battery. Trigger: With no battery connected, bus voltage lower than set value. Recovery: Restores after battery connected, or grid connected, or 10 min later.

68Alarm 68: Battery under SOC shutdown

MG6500-48 (Focus 6.2 kW) ALARM CODE 68 — Battery under SOC shutdown. This is an ALARM, NOT a fault (red Fault LED flashes, LCD shows 'ALA 68', the inverter keeps running). Action: Alarm; unit goes to standby. Trigger: BMS reports SOC lower than the BSU set value (Program 46). Recovery: Restores when: low-SOC shutdown disabled, OR BMS comms disabled, OR SOC rises to set value + 5%.

69Alarm 69: Battery below SOC warning

MG6500-48 (Focus 6.2 kW) ALARM CODE 69 — Battery below SOC warning. This is an ALARM, NOT a fault (red Fault LED flashes, LCD shows 'ALA 69', the inverter keeps running). Action: Alarm; stays in standby if already in standby. Trigger: Lithium SOC lower than set + 5% (grid/battery mode) or set + 10% (standby). Recovery: Restores when: low-SOC shutdown disabled, OR BMS comms disabled, OR SOC rises to set value + 10%.

72Alarm 72: Battery can not startup

MG6500-48 (Focus 6.2 kW) ALARM CODE 72 — Battery can not startup. This is an ALARM, NOT a fault (red Fault LED flashes, LCD shows 'ALA 72', the inverter keeps running). Action: Alarm. Trigger: During standby, battery voltage lower than the allowed startup voltage. Recovery: Restores after battery voltage rises above the allowed startup voltage.

77Alarm 77: Grid power is unstable

MG6500-48 (Focus 6.2 kW) ALARM CODE 77 — Grid power is unstable. This is an ALARM, NOT a fault (red Fault LED flashes, LCD shows 'ALA 77', the inverter keeps running). Action: Alarm. Trigger: Lost grid power three times within 5 minutes. Recovery: Restores after 5 minutes.

LCD Setting Programs (01–61)

MG6500-48 (Focus 6.2 kW) LCD SETTING PROGRAMS / DISPLAY SETTINGS. Enter setup: hold ENTER 2 s; UP/DOWN to pick a program; ENTER to confirm; ESC to exit. CRITICAL CAVEAT for MG6500-48 (Focus 6.2 kW): the manual's setting tables print 24 V-system voltage numbers (e.g. 23 V, 28.2 V), but this is a 48 V unit — the CUS constant-voltage default of 56.4 V (exactly 2×28.2) confirms it. Therefore: error/alarm CODE MEANINGS and behaviours are reliable, but DO NOT quote absolute voltage setpoints from the manual to a 48 V customer — the real values are ~2× (e.g. CV ≈ 56.4 V, float ≈ 54.4 V). When in doubt, read the value off the unit's own LCD or escalate; never invent a number. PROGRAMS: Program 01 — Output voltage (display 'OPU230'): default 230 V; options 208 / 220 / 230 / 240 V. At 208 V the rated output power is reduced to 90%. | Program 02 — Output frequency (display 'OPF 50'): default 50 Hz; options 50 / 60 Hz. | Program 03 — Output source priority (display 'OPP…'): default Grid first; options Grid first / Solar first / PBG / MKS (generator). Grid first: grid powers loads, solar charges battery. Solar first: solar powers loads first. PBG: solar→battery→grid order. MKS: generator priority. | Program 04 — Input mode (display 'nOd APP'): default APP; options APP (appliances ~10 ms) / UPS (computers ~10 ms) / GEN (generator AC-in ~20 ms). | Program 05 — Charger source priority (display 'CHP PNG'): default PNG (PV+Grid); options PNG = PV and grid together / OPV = only PV / PVF = PV first. | Program 06 — Grid charging current (display 'ICC 80'): default 80 A; options 2/10/20/30/40/50/60/70/80/90/100/110/120/130/140/150/160 A. | Program 07 — Maximum charging current (PV+grid total) (display 'nCC120'): default 120 A; options 2…160 A (same steps as Program 06). | Program 08 — Menu default (auto-return to first page) (display 'ndF ON'): default ON; options ON / OFF. ON: return to first page after 1 min idle. | Program 09 — Auto restart on overload (display 'LFS ON'): default ON; options ON / OFF. | Program 10 — Auto restart on over-temperature (display 'EFS ON'): default ON; options ON / OFF. | Program 11 — Main input cut warning (display 'nIP ON'): default ON; options ON / OFF. ON: buzzer sounds 5 s when grid/PV input is lost. | Program 12 — Energy-saving mode (display 'PvS OFF'): default OFF; options ON / OFF. ON: in battery mode, output stops if load < 25 W and loops; resumes if load > 35 W. | Program 13 — Overload transfer to bypass (display 'OL OFF'): default OFF; options ON / OFF. ON: in PBG/MKS mode, transfer to bypass (grid) on overload. | Program 14 — Silent mode (display 'nUE OFF'): default OFF; options ON / OFF. ON: buzzer stays silent on alarms/faults (button sound unaffected). | Program 15 — Battery return-to-grid voltage point (display 'bELi230'): default AGM/FLD 23 V; LIB 23.8 V; FEL 24.8 V; CUS 23.8 V; options AGM/FLD [22,26]; LIB/FEL/CUS [20,25]. ⚠ Values shown are 24 V-system; on this 48 V unit the real setpoint is ~2×. | Program 16 — Switch-back-to-battery voltage point (display 'bELi260'): default AGM/FLD 26 V; LIB 27.2 V; FEL 26.2 V; CUS 27.2 V; options AGM/FLD [24,29]; LIB/FEL/CUS [23,29]. ⚠ 24 V-system values; ~2× on this 48 V unit. | Program 17 — Battery type (display 'bAL…'): default AGM; options AGM / FLD (flooded) / LIB (ternary lithium) / FEL (lithium iron) / CUS (user-defined). Set LIB or FEL to enable BMS comms (see Program 44). | Program 18 — Battery low voltage point (BAL → Alarm 52) (display 'bALU220'): default LIB 23.8 V; FEL 24 V; CUS = LIB; AGM/FLD 22 V (fixed); options LIB/FEL [20.6,25]. This is the threshold that raises Alarm 52. ⚠ 24 V-system value. | Program 19 — Battery shutdown voltage point (BAU → Alarm 51) (display 'bALU210'): default LIB 23 V; FEL 21 V; AGM/FLD 21 V (fixed); CUS = LIB; options LIB/FEL [20,24]. Threshold for Alarm 51 / shutdown. ⚠ 24 V-system value. | Program 20 — Constant-voltage (CV) charge set point (display 'bCU28.2'): default AGM 28.2 V (fixed); FLD 29 V; LIB 28.2 V; FEL 27.6 V; CUS 56.4 V; options LIB/FEL/CUS [24,30]. CV must be higher than float (Program 21). Note CUS default 56.4 V confirms this is really a 48 V system. | Program 21 — Float charge set point (display 'bFL270'): default AGM/FLD 27 V (fixed); CUS 27.6 V; LIB 27.6 V; FEL 27.2 V; options CUS [24,30]; LIB/FEL [25,29]. Float must be lower than CV (Program 20). | Program 22 — Grid low-voltage point (display 'LL154'): default APP/GEN 154 V; UPS 185 V; options APP/GEN [90,154]; UPS [170,200]. | Program 23 — Grid high-voltage point (display 'LHU264'): default 264 V; options APP/GEN [264,280]; UPS fixed 264 V. | Program 24 — Auto turn-off backlight (display 'AEb ON'): default ON; options ON / OFF. ON: backlight off after 1 min idle. | Program 25 — Inverter soft start (display 'SFE OFF'): default OFF; options ON / OFF. ON: output ramps 0→target gradually. Single-machine mode only. | Program 26 — Reset to factory settings (display 'SEd OFF'): default OFF; options ON / OFF. Set ON to restore defaults. Cannot be set in battery mode. | Program 29 — Battery disconnection alarm (display 'SbA OFF'): default OFF; options ON / OFF. OFF: no alarm when battery disconnected. | Program 31 — Equalization voltage point (display 'EQU292'): default FEL 28 V; AGM/FLD/LIB/CUS 29.2 V; options [24,30]. ⚠ Do NOT use equalization on lithium batteries. | Program 32 — Equalization charging time (display 'EQEOFF'): default OFF; options OFF or [5,900] min (5-min steps). | Program 33 — Equalization delay (timeout) (display 'EQd120'): default 120 min; options [5,900] min (5-min steps). | Program 34 — Equalization interval (display 'EQi 30'): default 30 days; options [1,90] days. | Program 35 — Enable equalization immediately (display 'EQnOFF'): default OFF; options ON / OFF. | Program 36 — Grid-tie (feed-in) function (display 'GEi OFF'): default OFF; options OFF / INT. INT: PV surplus feeds to grid per output-source priority. | Program 37 — Max grid-tie power (display 'GEP 50'): default 5.0 kW; options [0,5.0] kW (0.5 kW steps). | Program 38 — Dual-output low-voltage shutdown point (display 'db240'): default 24 V; options [22,30] V. Only models with a second AC output. ⚠ 24 V-system value. | Program 39 — Dual-output duration (display 'dbEFUL'): default OFF; options [5,900] min or FUL (unlimited). Only models with a second output. | Program 40 — Dual-output battery-mode cut-off SOC (display 'dbS 20'): default 20%; options [5,90] or OFF. Only models with a second output. | Program 44 — BMS communication function (display 'bnSOFF'): default OFF; options CVT / PYL / GRO / VOL / IRO / PAR. PYL=PYLON, GRO=GROWATT (485+CAN); others 485. If comms abnormal → Alarm 56. | Program 45 — BMS ID (display 'bnI AtO'): default Auto (AtO); options AtO or [0,15] (A–F = 10–15). | Program 46 — Low SOC shutdown (BSU) (display 'bSU 20'): default 20%; options [5,50]. SOC at set value → shutdown + Alarm 68. Standby restart needs set + 10% else Alarm 69. | Program 47 — High SOC → battery (display 'SEb 90'): default 90%; options [10,100]. PBG mode: switch to battery when SOC reaches set value. | Program 48 — Low SOC → grid (display 'SEG 50'): default 50%; options [10,90]. PBG mode: switch to grid when SOC falls below set value. | Program 61 — Battery max discharge current (display 'ndC190'): default 190 A; options [10,190] A (5 A steps) or OFF. Over limit → Alarm 60; if continuous over-current 5 s → Fault 14.

Display Pages & LED Indicators

MG6500-48 (Focus 6.2 kW) DISPLAY INFORMATION & LED INDICATORS. Press UP/DOWN to cycle info pages: P1: Daily solar power generation (kWh) | P2: Total solar power generation (kWh) | P3: Lithium battery voltage and current (shows ERR if BMS comms fail; hidden if BMS disabled) | P4: Lithium battery temperature and SOC | P5: Lithium battery rated and remaining capacity | P6: Lithium battery max charge voltage and min discharge voltage | P7: Lithium battery max charge current and max discharge current | P8: Lithium battery alarm and fault info (NUL = none) | P9: Inverter firmware version. LED INDICATORS: AC (green): Solid = mains normal and in mains operation; Flashing = mains normal but not yet in mains operation; Off = mains abnormal | Inverter (yellow): Solid = output powered by battery or PV (battery mode); Off = other states | Charging (yellow): Solid = float charging; Flashing = constant-voltage charging; Off = other states | Fault (red): Solid = fault; Flashing = warning/alarm; Off = working normally. LCD charge-stage icons: CC=constant current, CV=constant voltage, FLOAT=float charging.

Troubleshooting

MG6500-48 (Focus 6.2 kW) TROUBLESHOOTING. Fault 5 — over temperature: Check the fan: not connected or loose wiring. A disconnected fan for >5 min triggers Fault 5. | Fault 12 — inverter short circuit: Check output terminals for a short (e.g. a screw piercing the LN). Triggers when inverter V < 80 V and current > 30 A within 100–120 ms. | Fault/Alarm 58 — fan malfunction: Fan rotating < 8 times in 2 s. Check fan connection; if connected, check the fan-detection circuit (cold-solder under the control-board socket) or a damaged fan. | Unable to start — battery: Needs ≥ 11.5 V per cell to start in battery mode. Causes: bad calibration or low battery voltage. Verify voltage sampling/calibration and measure terminal voltage. CRITICAL: set the battery voltage to match the machine model — the wrong battery voltage can cause a capacitor explosion. | Unable to start — utility power: Check for a mains-terminal short (screw piercing live/neutral) and wiring errors (mains input wired to the output terminals). | Unable to start — PV: Check PV input voltage isn't too close to the threshold; for low-voltage versions verify control-board firmware compatibility. | PV not charging: Wrong battery voltage can damage the PV-side auxiliary supply, losing comms with the main control.. CRITICAL CAVEAT for MG6500-48 (Focus 6.2 kW): the manual's setting tables print 24 V-system voltage numbers (e.g. 23 V, 28.2 V), but this is a 48 V unit — the CUS constant-voltage default of 56.4 V (exactly 2×28.2) confirms it. Therefore: error/alarm CODE MEANINGS and behaviours are reliable, but DO NOT quote absolute voltage setpoints from the manual to a 48 V customer — the real values are ~2× (e.g. CV ≈ 56.4 V, float ≈ 54.4 V). When in doubt, read the value off the unit's own LCD or escalate; never invent a number.