55Fault

DEYE inverter error 55 (F055)

DC busbar voltage is too high

Also displayed as F055 / F55 on some models.

Faultthe inverter cuts its output and the red LED stays solid until the fault is cleared.

Severity differs by model — check your model below.

The exact meaning depends on your model:

Also applies to:SUN-120K-G01P3-EU-BM8SUN-125K-G01P3-EU-BM8SUN-130K-G01P3-EU-BM8SUN-135K-G01P3-EU-BM8SUN-136K-G01P3-EU-BM8SUN-7K-G02P1-EU-AM2SUN-7.5K-G02P1-EU-AM2SUN-8K-G02P1-EU-AM2+18

What it means

DC busbar voltage is too highThe DC bus voltage is above the limit.

Cause: The DC bus (Ubus) voltage is above the limit - usually the PV input voltage is too high because too many solar panels are connected in series, or the Ubus detection circuit is faulty.

How to fix it

  1. Check the PV voltage and the Ubus voltage and their detection circuit; if the PV input voltage exceeds the limit, reduce the number of solar panels in series
  2. For the Ubus voltage, check the LCD display.

Source: 041_BManual_SUN-120_125_130_135_136K-G01P3-EU-BM8_20251021_en_a2166559.pdf, p.63 · 065_BManual_SUN-7_7.5_8K-G02P1-EU-AM2_20260625_en_4466f08b.pdf, p.53 · 032_BManual_SUN-9_10_10.5K-G02P1-EU-AM2_20260625_en_df0f2106.pdf, p.53 · +4 more official manuals

Also applies to:SUN-6K-G06-LV-P1SUN-8K-G06-LV-P1SUN-6K-G06P3-EU-BM2-LV-P1SUN-8K-G06P3-EU-BM2-LV-P1SUN-10K-G05-LVSUN-12K-G05-LVSUN-15K-G05-LVSUN-15K-G06P3-EU-BM2-P1+71

What it means

DC busbar voltage is too highThe DC bus voltage exceeded its upper limit.

Cause: PV input voltage above the permitted limit (too many solar panels in series), or a problem in the Ubus voltage detection circuit.

How to fix it

Check the PV voltage, the Ubus voltage, and its detection circuit; if the PV input voltage exceeds the limit, reduce the number of solar panels in series; check the Ubus voltage on the LCD display.

Source: 063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf, p.59 · 031_BManual_SUN-1_1.5_2_2.2_2.5_2.7_3_3.3_3.6_4K-G04P1-EU-AM1_20260624_en_15adc00c.pdf, p.55 · 036_BManual_SUN-3_4_5_6_7_8_9_10_12_15K-G06P3-EU-BM2_20250506_en_0eb78440.pdf, p.58

Also applies to:SUN-5K-SG01HP3-EU-AM2SUN-6K-SG01HP3-EU-AM2SUN-8K-SG01HP3-EU-AM2SUN-10K-SG01HP3-EU-AM2SUN-12K-SG01HP3-EU-AM2SUN-15K-SG01HP3-EU-AM2SUN-20K-SG01HP3-EU-AM2SUN-25K-SG01HP3-EU-AM2+9

What it means

Battery 1 Voltage HighBAT1_VoltHigh_Fault - the terminal voltage of battery input 1 is too high.

Cause: The voltage measured at the battery 1 terminals is above the limit.

How to fix it

  1. Check whether the battery 1 terminal voltage is high
  2. Restart the inverter 2 times and restore the factory settings.

Source: 037_BManual_SUN-5_6_8_10_12_15_20_25K-SG01HP3-EU-AM2_20260224_en_9ef2717c.pdf, p.52 · 050_BManual_SUN-29.9_30_35_40_50K-SG01HP3-EU-BM3_4_20260224_en_544e1b2f.pdf, p.53 · 062_BManual__SUN-60_70_75_80K-SG02HP3-EU-EM6_20260224_en_38cbc9f6.pdf, p.53

Also applies to:SUN-5K-SG04LP3-EUSUN-6K-SG04LP3-EUSUN-8K-SG04LP3-EUSUN-10K-SG04LP3-EUSUN-12K-SG04LP3-EUSUN-3K-SG05LP3-EU-SM2SUN-4K-SG05LP3-EU-SM2SUN-5K-SG05LP3-EU-SM2+9

What it means

DC Busbar Voltage Too HighDC busbar voltage is too high - the internal BUS voltage is too high.

Cause: The DC busbar (BUS) voltage is too high because the battery voltage is too high or the PV input voltage is outside the allowed range.

How to fix it

  1. Check whether the battery voltage is too high
  2. Check the PV input voltage and make sure it is within the allowed range
  3. Seek help from us if it cannot go back to the normal state.

Source: 038_BManual_SUN-5_6_8_10_12K-SG04LP3-EU_20260319_en_081932c1.pdf, p.47 · 040_BManual_SUN-3_4_5_6_8_10_12K-SG05LP3-EU-SM2_20260319_en_b0183b7d.pdf, p.47 · 044_BManual_SUN-14_15_16_18_20K-SG05LP3-EU-SM2_20260319_en_ac7cdbd1.pdf, p.47

AI-W5.1 ESS

Energy storage systemFault

Also applies to:AI-W5.1-5P3-EU-B-ESSAI-W5.1-6P3-EU-B-ESSAI-W5.1-8P3-EU-B-ESSAI-W5.1-10P3-EU-B-ESSAI-W5.1-12P3-EU-B-ESS

What it means

DC busbar voltage is too highBUS voltage is too high.

Cause: The internal BUS voltage exceeded its limit - battery voltage too high or PV input voltage above the allowed range.

How to fix it

  1. Check whether the battery voltage is too high and that the PV input voltage is within the allowed range.
  2. Seek help from Deye if it does not recover.

Source: 002_Download_4e90fe7a.pdf, p.48

GB-SL / GB-SL Pro ESS

Energy storage systemFault

Also applies to:GB-SL5K-EUGB-SL6K-EUGB-SL8K-EUGB-SL10K-EUGB-SL12K-EUGB-SL15K-EUGB-SL20K-EUGB-SL Pro 5K-EU+6

What it means

BAT1_VoltHigh_FaultBattery 1 terminal voltage is too high.

Cause: The voltage measured at the battery 1 terminals exceeded the limit - battery over-voltage or wrong battery settings.

How to fix it

  1. Check the battery 1 terminal voltage, restart the inverter twice and restore the factory settings.
  2. Seek help from Deye if it does not recover.

Source: 081_deye_gb_sl_pro_user_manual_46fa941a.pdf, p.51 · 010_Download_cc05df18.pdf, p.46

Also applies to:RW-L2.5ARW-L5.1RW-L10.2RW-F16SE-F5SE-F5 PlusSE-F5 ProSE-F12+7

What it means

TEMP_OPEN_WIRE_FAILAn open wire was detected in the temperature-sensor harness.

Cause: A temperature-sensor lead is broken or disconnected, so the BMS reads an open circuit on that channel.

How to fix it

  1. Restart the battery.
  2. If the code persists, contact Deye support.

Source: 093_Deye_RW-L2.5A_User_Manual_EN_89188fb8.pdf, p.10 · 019_Download_4a609b7e.pdf, p.10 · 021_Download_f81ba1e7.pdf, p.10 · +6 more official manuals

GB-A HV Battery

BatteryWarning

Also applies to:GB-A

What it means

ALARM_ID_W5500_SPI_COMM_FAILThe W5500 (Ethernet controller) SPI communication fails.

Cause: The BMS lost internal SPI communication with its W5500 Ethernet controller chip - a fault on the network interface, affecting monitoring connectivity.

How to fix it

  1. Restart the system.
  2. If the fault persists, contact Deye support for service of the communication board.

Source: 008_deye_ess_user_manual_gb_a_jpnen_v02_20250829_3fea617e.pdf, p.14

Frequently asked questions

What does error 55 mean on a DEYE inverter?
It depends on the model — 13 devices use code 55. On the SUN G01P3-EU-BM8 Series it means: DC busbar voltage is too high. The card for each model on this page gives its exact meaning and fix.
Is error 55 a fault or a warning?
It depends on the model: on some models 55 is a fault (output cut, red LED solid), on others a warning (red LED flashing, unit keeps running). Check the card for your model on this page.
How do I clear or fix error 55?
1. Check the PV voltage and the Ubus voltage and their detection circuit; if the PV input voltage exceeds the limit, reduce the number of solar panels in series. The exact steps for each affected model are listed on this page.

Related error codes

Prefer the full written guide? Read the complete DEYE inverter error-code guide

Compiled from official DEYE user manuals. Always consult your device manual and a qualified technician before performing repairs.