Complete Guide to SV-iG5A Inverter

OV (overvoltage)

Trigger condition: The DC bus voltage exceeds 400V (200V level) or 800V (400V level).

Main reason: The deceleration time is too short, and the regenerative energy of the motor is injected back. Solution: Extend deceleration time, install braking resistors or braking units. In addition, transient surges in the power supply can also cause OV, so check if there is a capacitor bank connected to the input side.

LV (low voltage)

Trigger condition: The bus voltage is below 180V (200V level) or 360V (400V level).

Reason: Input phase loss, insufficient power capacity (if starting a large motor directly), loose wiring terminals. If it occurs instantaneously during operation, the "instantaneous power failure restart" function of H22 can be enabled, setting 0-10 automatic restart attempts (H26) and restart waiting time (H27).

OH/IOL/OLT (overheating/overload)

OH: The temperature of the heat sink exceeds 85 ℃. Check if the cooling fan is stuck, if the air duct is blocked, and if the ambient temperature is too high. When the fan malfunctions, the keyboard displays "FAN", and H78 can choose to continue running or stop for protection.

IOL: The frequency converter is overloaded and usually operates at 150% per minute. Need to increase the capacity of the frequency converter or reduce the load.

OLT: Motor overload detected by internal electronic thermal overload relay. Need to check the settings of F51 (one minute overload multiple), F52 (continuous current), and F57/F58. If the motor is a constant torque load but operates at low speed for a long time, an independent fan needs to be added.

ETH (motor thermal overload)

Attention: This protection is based on the output current calculation of the frequency converter. It will fail when driving multiple motors or when the number of poles is greater than 4. In this case, an external thermal relay needs to be installed on each motor.

GF (Ground Fault)

The frequency converter has detected that the output leakage current to the ground exceeds the internal threshold. The common reasons are that the motor winding is damp or the cable insulation is reduced. You can first disconnect the motor wire and run the frequency converter without load. If GF still reports, it may be a fault with the Hall sensor or motherboard.

PO (Output Phase Loss)

Triggered when any output phase current is missing. Check if the motor wire is loose and if the contactor is not engaged. For low-power motors (0.4kW), false alarms may occur at low carrier frequencies. It is recommended to lower the H39 or increase the I54/I55 detection threshold appropriately (although the manual does not disclose the adjustment method, it is recommended to replace spare parts for testing).

Communication error (Err)

When using RS485 communication, check whether the station numbers, baud rates, and parity bits of I60~I65 are consistent with the main station. Setting I62 to 0 can maintain the last frequency in case of communication loss, while setting it to 2 will slow down and stop the vehicle.

Preventive maintenance and component replacement cycle

Although SV-iG5A is durable, its internal electrolytic capacitors and cooling fans will age over time and temperature. Based on manual maintenance suggestions:

Typical failure phenomena of component replacement cycle

Cooling fan noise increases over the past 3 years, reports FAN faults, and frequently generates OH

The 4-year capacity decrease of the DC bus capacitor in the main circuit resulted in LV tripping and large voltage ripple

Abnormal parameter storage and chaotic keyboard display of electrolytic capacitors on the control board after 4 years

The relay's indefinite contacts are stuck or unable to engage

Attention to replacement operation: Be sure to perform it after power off and discharging. To replace the fan, open the bottom cover (press both sides and pull out), and refer to the original label for the model. For naturally cooled models (such as SV004iG5A-2, 0.4kW 3-phase) without fans, it is necessary to ensure good natural convection inside the cabinet.

Parameter backup: Before replacing the control board or upgrading software, it is necessary to read all parameters through RS485 (using the DriveView software provided by LS) or manually record key values. The new control board needs to set the same parameter group and perform H93=1 initialization, and then write them one by one.

Upgrade and Alternative Options

For the discontinued SV-iG5A, if the main control board is damaged and cannot be repaired, the following can be considered:

Directly replace with models of the same series that can still be purchased (such as the iG5A improved version or the next generation iS7 series). However, it is important to note the differences in base size and wiring diagram.

Using communication option modules (DeviceNet or Ethernet, requiring the purchase of a communication type host with the suffix "FB"), connect the frequency converter to the upper network to achieve remote monitoring and batch parameter download.

The remote keyboard (model 64100022, etc.) can lead the operation panel to the cabinet door for easy debugging. When using for the first time, execute H91 (read parameters to remote keyboard memory), otherwise the keyboard will not display; Write and execute H92.