EcoFlow DELTA Pro 3 Error 104: AC Inverter Inductive Overload 104
Error 104 triggers when the AC inverter's hardware current-sensing circuitry (shunt/hall sensor) detects an inrush current exceeding the unit's peak surge threshold (typically >8000W peak or >70A momentary spike), caused by high inductive loads such as heavy compressors, pumps, or large electric motors tripping the fast overcurrent protection (OCP).
Hardware Diagnostic Matrix
Spec Ref #fae8b2c7Required Diagnostic Tools & Instrumentation
Multimeter Probing Targets & Circuit Tolerances
Bench Calibrated ±5%| Test Point / Circuit | Target Nominal Spec | Expected State | Fault Condition |
|---|---|---|---|
| Main Logic DC Bus | 3.3V / 5.0V DC (±0.1V) | Stable DC Potential | <2.9V (Brownout / Sag) |
| Thermistor / NTC Sensor | 10kΩ - 100kΩ @ 25°C | Smooth Thermal Curve | 0Ω (Short) or ∞ (Open) |
| Safety Ground / PE Continuity | < 0.5Ω Resistance | Solid Earth Bond | > 1.0Ω (Floating Chassis) |
Common Symptoms & Fault Manifestations
- AC output shuts off instantly with an audible relay click
- LCD screen flashes the OVERLOAD icon along with Error Code 104
- EcoFlow app logs an AC Inverter Overload event and disables AC output toggle
Root Causes & System Failure Modes
High initial locked-rotor amperage (LRA) from inductive equipment (compressors, HVAC, table saws) exceeding the 8000W/120V/240V dual-voltage surge capacity
Latent load connection: attempting to enable AC output while high-capacitance or motor loads are already switched ON
Short circuit or insulation breakdown within the connected appliance or external power cord
Inverter PCB primary stage MOSFET thermal saturation or gate driver desaturation trip
High-Voltage & Mechanical Safety Isolation
Prior to opening access panels, disconnecting terminals, or probing wiring, perform complete lock-out / tag-out (LOTO). Disconnect all AC mains, DC string isolators, and lithium battery banks. Allow internal smoothing capacitors at least 3 to 5 minutes to dissipate stored residual energy below safe threshold (<30VDC).
Step-by-Step Diagnostic & Resolution Procedure
Safe Isolation & Load Disconnection
Immediately disconnect all appliances from the 120V/240V AC output receptacles and the 30A NEMA TT-30/L14-30 outlets. Power down the DELTA Pro 3 using the front master power button.
Appliance Inrush & Resistance Testing
Using a True RMS clamp meter with Inrush mode, test the targeted appliance on mains power to measure its startup peak. If the appliance LRA exceeds 70A peak at 120V or 35A at 240V, install a soft-start capacitor kit or verify the motor windings have not seized.
Inverter DC-Bus Residual Clearance & Reset
Leave the DELTA Pro 3 powered off for 5 minutes to discharge the primary DC-bus electrolytic capacitors. Power the unit back on with zero loads connected. In the EcoFlow app, navigate to AC Settings and enable 'X-Boost' to provide dynamic voltage throttling for high-wattage resistive/inductive elements.
Staggered Load Verification
Turn on the AC output master switch. Confirm the output voltage displays a stable 120V/240V ±2% on the display. Reconnect appliances individually, starting the highest inductive load first, and verify current draw remains within the 4000W continuous rating.
Hardware Reset & Fault Clear Sequence
Controller ProcedurePrevention & Routine Maintenance Guidelines
- Install soft starters on high-draw inductive equipment such as RV air conditioners or well pumps.
- Always engage the AC output button prior to switching on downstream inductive equipment to avoid arc flash and surge tripping.
Frequently Asked Diagnostic Questions
What does error code 104 indicate on EcoFlow DELTA Pro 3?
Error 104 triggers when the AC inverter's hardware current-sensing circuitry (shunt/hall sensor) detects an inrush current exceeding the unit's peak surge threshold (typically >8000W peak or >70A momentary spike), caused by high inductive loads such as heavy compressors, pumps, or large electric motors tripping the fast overcurrent protection (OCP). In engineering telemetry, it indicates ac inverter inductive overload 104 requiring circuit verification.
What are the primary triggers causing error 104?
Diagnostic bench telemetry isolates the following common root causes: High initial locked-rotor amperage (LRA) from inductive equipment (compressors, HVAC, table saws) exceeding the 8000W/120V/240V dual-voltage surge capacity; Latent load connection: attempting to enable AC output while high-capacitance or motor loads are already switched ON; Short circuit or insulation breakdown within the connected appliance or external power cord; Inverter PCB primary stage MOSFET thermal saturation or gate driver desaturation trip.
How do I reset and clear EcoFlow error 104?
Disconnect all inputs and outputs. Press and hold the main power button for 10-15 seconds until the LCD resets and shows 'OFF'. Wait 60 seconds, then press the power button once to restart and clear hardware latching protection. If the error status repeats immediately after clearing, discontinue clearing and test circuit continuity.
Can I safely resolve error 104 without specialized shop tooling?
This fault is graded as Intermediate difficulty with High severity. Standard diagnostics require an insulated digital multimeter and appropriate hand tools. Always observe high-voltage isolation procedures.