Hitachi SJ700 Fault Codes & Troubleshooting List 2026

Hitachi SJ700 Fault Codes & Troubleshooting List 2026 – Troubleshoot your Hitachi SJ700 high-performance inverter with our updated 2026 guide. Learn to interpret E01-E83 trips, view detailed fault logs in parameters d081-d086, and reset the drive.

The Hitachi SJ700 is a premier, high-performance industrial inverter that succeeded the popular SJ300 series. Designed for the most demanding heavy-duty applications—such as cranes, extruders, and large-scale manufacturing—it is known for its exceptional torque control and long-term reliability. In 2026, the SJ700 remains a cornerstone of industrial automation. When the drive trips, the 4-digit LED display flashes an error code (e.g., E01, E07, E14).

This guide provides the most updated resources for 2026 to help you diagnose these error codes and get your heavy-duty systems back into production quickly.

Hitachi SJ700 Fault Codes Reference Table

Below is the reference for the SJ700 protective functions. Please refer to this table to match the alphanumeric code on your inverter with the specific hardware or system issue.

Fault Code and Meaning	Cause and Remedy
E01 / OC.Drive Overcurrent protection (During constant speed operation)	Cause: The motor load has fluctuated sharply. Short circuit of output connections. Ground fault. Remedy: Eliminate the load fluctuation. Check the output cables for short circuits. Check the output cables and motor for ground faults.
E02 / OC.Decel Overcurrent protection (During deceleration)	Cause: The inverter has decelerated the motor too quickly. Remedy: Increase the deceleration time.
E03 / OC.Accel Overcurrent protection (During acceleration)	Cause: The inverter has accelerated the motor too quickly. The motor has been locked. The torque boost current has been set too high. Remedy: Increase the acceleration time. Check the motor and wiring. Reduce the boost current.
E04 / Over.C Overcurrent protection (Others)	Cause: The DC braking force is too high. Current detector (CT) failure. Remedy: Reduce the braking force. Replace or repair the Current Detector (CT).
E05 / Over.L Overload protection	Cause: The motor load is too high. The thermal level setting is inappropriate. Remedy: Reduce the load factor. Adjust the thermal level appropriately. If operating at 5Hz or less, reduce torque boost current.
E06 / OL.BRD Braking resistor overload protection	Cause: The inverter has decreased the motor speed too quickly. The operation cycle is too short. The set BRD operation rate is too low. Remedy: Increase the deceleration time. Prolong the operation cycle. Adjust the setting to an appropriate level (confirm resistor capacity).
E07 / Over.V Overvoltage protection	Cause: The inverter has decreased the motor speed too quickly (regenerative energy). Ground fault. Motor rotated by the action of the load. Remedy: Increase the deceleration time. Check the output cables and motor for ground faults. Reduce the regenerative energy.
E08 / EEPROM EEPROM error	Cause: Noise sources located near the inverter. Cooling efficiency has deteriorated (overheating). Remedy: Remove noise sources. Check the heat sink for clogging and clean it. Replace the cooling fan. Initialize inverter and reset parameters.
E09 / Under.V Undervoltage error	Cause: Power supply voltage has dropped. Power supply capacity is insufficient. Thyristor damage. Remedy: Check the power supply and capacity. Check the thyristor (repair inverter).
E10 / CT CT (Current Detector) error	Cause: The internal Current Detector (CT) has failed. Remedy: Repair the inverter.
E11 / CPU CPU error	Cause: Internal CPU malfunction. Noise interference. Remedy: Remove noise sources located near the inverter. Repair the inverter if hardware failure.
E12 / EXTERNAL External trip	Cause: An error has occurred in the external equipment/device connected to the inverter. Remedy: Recover the external equipment from the error.
E13 / USP USP error (Unattended Start Protection)	Cause: The inverter power was turned on while an operation signal was already input/active. Remedy: Reset the operation command (turn switch off), and then turn on the inverter power.
E14 / GND.Flt Ground-fault protection	Cause: Ground fault between inverter output and motor. Inverter hardware abnormality. Remedy: Check output cables and motor. Remove output cables and check the inverter itself.
E15 / OV.SRC Input overvoltage protection	Cause: The input voltage is high while the inverter is stopped (kept above specification level for 100s). Remedy: Lower the input voltage. Suppress power voltage fluctuation. Connect an AC reactor between power supply and inverter.
E16 / Inst.P-F Instantaneous power failure protection	Cause: Power supply voltage dropped for 15ms or more. Poor contacts in MCB or magnetic contactors. Remedy: Recover the power supply. Replace the MCB and magnetic contactor.
E20 / OH.stFAN Temperature error (Low cooling-fan speed)	Cause: Cooling efficiency lowered (fan failure). Heat sink clogged. Remedy: Replace the cooling fan. Clean the heat sink.
E21 / OH.fin Temperature error (Main circuit high temp)	Cause: Improper installation (not vertical). High ambient temperature. Remedy: Check the installation (ensure vertical mounting). Lower the ambient temperature.
E23 / GA.COM Gate array communication error	Cause: Noise interference. Internal communication cable disconnected. Remedy: Remove noise sources. Check the internal connectors.
E24 / PH.fail Phase loss input protection	Cause: Phase loss in power input. Poor contacts in MCB/Magnetic contactor. Remedy: Check power supply input wiring. Replace MCB or magnetic contactor.
E25 / Main.Cir Main circuit error	Cause: Malfunction due to noise. Main circuit element (IGBT) damage. Remedy: Remove noise sources. Check the IGBT and output circuit. Repair the inverter.
E30 / IGBT IGBT error (Instantaneous overcurrent)	Cause: Short circuit in output. Ground fault. Main circuit element (IGBT) damage. Remedy: Check output cables and motor for shorts/ground faults. Check the IGBT. Clean heat sink (if clogging caused overheat).
E35 / TH Thermistor error	Cause: Motor temperature is high. Internal thermistor of motor damaged. Noise in thermistor signal. Remedy: Check motor temperature. Check the thermistor. Separate thermistor wiring from other wiring (noise).
E36 / BRAKE Braking error	Cause: Brake has not turned on/off correctly. Wait time (b124) is too short. Braking confirmation signal wiring issue. Remedy: Check the brake. Increase the wait time setting [b124]. Check the wiring.
E37 / EMR Emergency stop	Cause: Error in external equipment (emergency stop function enabled). Noise sources. Remedy: Recover external equipment from error. Remove noise sources.
E38 / OL-LowSP Low-speed overload protection	Cause: Overload occurred during motor operation at very low speed (0.2Hz or less). Remedy: Reduce the load factor.
E41 / NET.ERR Modbus communication error	Cause: Timeout due to line disconnection or setup issue. Remedy: Check communication speed setting. Check wiring distance. Check connections.
E60 to E69 (Remote: OP1-0 to OP1-9) Option 1 Board Errors (Slot 1)	Cause: E60: Encoder disconnection. E61: Excessive speed. E62: Positioning error. E63: Position control range trip. E69: Connection/Mounting error. Remedy: Check if option board is mounted correctly. Check encoder wiring and settings. Refer to the instruction manual for the specific Option Board (SJ-FB, SJ-DG, or SJ-DN).
E70 to E79 (Remote: OP2-0 to OP2-9) Option 2 Board Errors (Slot 2)	Cause: Similar causes to Option 1 errors but for the board in Slot 2. Remedy: Check board mounting. Refer to the specific option board manual.
E43 / PRG.CMD Invalid instruction (Easy Sequence)	Cause: Invalid instruction found in downloaded program or PRG terminal active with no program. Remedy: Check the program code.
E44 / PRG.NST Nesting count error	Cause: Subroutines or loops nested more than 8 levels deep. Remedy: Correct the program nesting structure.
E45 / PRG.ERR1 Execution error 1	Cause: Jump destination not found. Arithmetic overflow/underflow or division by zero. Undefined parameter or out of range setting. Remedy: Debug the Easy Sequence program.
E50 to E59 (PRG-0 to PRG-9) User trips 0 to 9	Cause: The inverter executed a “trip” instruction defined in the user program. Remedy: Check the condition in the program that triggers this trip.

How to Read SJ700 Faults via Monitor Parameters

The Hitachi SJ700 provides superior diagnostic visibility through its monitoring parameters. To get the most accurate data in 2026, you should utilize the d-group parameters to see the exact state of the drive at the moment of failure.

Trip History (d081 to d086): The SJ700 stores the last 6 major trips. Navigate to parameter d081 to see the most recent fault. Parameters d082 through d086 store previous error events in chronological order.
Status Snapshot: When viewing a trip in parameter d081, the display automatically alternates between the error code and the inverter status (Output Frequency, Current, and DC Bus Voltage) recorded at the exact millisecond of the trip.
ProDriveNext Software: For complex troubleshooting, you can connect your PC to the SJ700 using the ProDriveNext software via the RS485 or optional USB interface. This allows you to graph waveforms and identify if transient spikes are triggering E01 (Overcurrent) or E07 (Overvoltage) trips.

General Troubleshooting Steps

Before performing a manual reset on your Hitachi SJ700, perform these essential hardware checks to protect the internal IGBTs:

Overcurrent (E01 – E04): Indicates an instantaneous current spike. Check for a short circuit in the motor leads or a mechanically seized load. If the trip occurs during acceleration, check parameter F002 and ensure the torque boost settings are not too high.
Overvoltage (E07): This usually occurs when a high-inertia load decelerates too quickly. Increase the Deceleration Time in parameter F003 or check the integrity of the external braking resistor and its thermal switch.
Under-voltage (E09): Check the input AC power supply. A drop in line voltage or a blown input fuse is a common cause. In 2026, ensure your power distribution system is stable and not sagging under the load of other heavy machinery.

Frequently Asked Questions (FAQ)

Q: How do I reset a fault on the Hitachi SJ700?

A: Once the cause of the trip has been cleared, you can reset the inverter using these methods:

Press the Stop/Reset key on the digital operator.
Close the digital input terminal assigned to the RS (Reset) function (Terminal 5 is the default).
Perform a power cycle (Wait for the display and “Charge” lamp to go completely dark before turning power back on).

Q: What does “USP” mean?

A: USP (Unattended Start Protection) is a safety feature. It prevents the motor from starting unexpectedly if the Run command is already active when the drive is powered up. Turn the Run command OFF to clear the error.

Q: Why does my drive show “E14” (Ground Fault)?

A: E14 indicates that current is leaking to the ground on the output side. For large motors, this is often caused by moisture in the conduit or breakdown of motor winding insulation. Do not ignore this trip, as it can cause catastrophic drive failure.

Q: Where is the fault history stored?

A: You can find the history of the last 6 faults in Monitor Mode under parameters d081 through d086. Each entry provides the fault code and the electrical data at the time of the event.