How to Solve Common Problems of High-Protection Multipurpose Variable Frequency Drive

Troubles & Solutions

High-protection multipurpose variable frequency drives are widely used in harsh environments, such as water treatment, chemical processing, and mining. Due to their complex functions and demanding operating conditions, they are prone to issues such as overload, overheating, electromagnetic interference, and moisture corrosion. Understanding common problems and corresponding solutions for high-protection multipurpose variable frequency drives is crucial for ensuring stable system operation, reducing equipment failure rates, and extending service life. This also helps to improve maintenance efficiency, minimize downtime and maintenance costs, and serves as an essential prerequisite for achieving reliability and sustainable operation in automated systems.

Test the functions of a high-protection, multipurpose variable frequency drive.

Troubles & Solutions

Table 1: Troubles and Solutions for High-Protection Multipurpose Variable Frequency Drive
Fault Type	Possible Cause	Corrective Action
Inverter unit U-Phase protection	Overly rapid acceleration Internal damage to IGBTs in the corresponding phase Misoperation caused by interference Poorly connected drive lines Possible short circuit to ground	Increase acceleration time Replace power unit Check drive line connections Inspect peripheral equipment for strong sources of interference
Inverter unit V-phase protection
Inverter unit W-phase protection
Acceleration overvoltage	Excessively short deceleration time Abnormal input voltage Substantial energy feedback/regeneration Missing braking components Energy consumption braking function not activated Excessively short deceleration time=	Check input power supply Check if load deceleration time is too short, or if there is a motor restart while still rotating Energy consumption braking components need to be added. Check the settings of relevant function codes
Deceleration overvoltage
Constant speed overvoltage
Acceleration overcurrent	Excessively fast acceleration or deceleration Low grid voltage Undersized VFD power rating Sudden or abnormal load changes Ground fault or output phase loss External strong interference sources Overcurrent stall protection not enabled	Increase acceleration and deceleration times Check input power supply Select a VFD with a higher power rating Inspect the load for short circuits (ground faults or line-to-line shorts) or lock-rotor conditions Check output wiring Investigate for strong interference phenomena Review the settings of relevant function codes
Deceleration overcurrent
Constant speed overcurrent
DC bus undervoltage fault	Low grid voltage Overvoltage stall protection not enabled	Check the grid input power supply. Review the settings of relevant function codes
Motor overload	Excessively low grid voltage Incorrect motor rated current setting Motor lock-rotor or excessive sudden load change	Check grid voltage. Reset motor rated current. adjust torque boost settings
Variable frequency drive overload	Excessively fast acceleration Restarting a rotating motor Excessively low grid voltage Excessive load Undersized motor for application	Increase acceleration time Avoid shutdown and restart Check grid voltage Select a higher-power variable frequency drive Choose an appropriately sized motor

The above are fault types, possible causes, and solutions encountered during the use of high-protection multipurpose variable frequency drives. You may refer to them for troubleshooting. If the issue persists, please feel free to contact us, and we will do our utmost to assist you.