Why does my Lenze i550 Inverter show a mains phase fault and how to fix it?
- RrichardleonAug 30, 2025
If your Lenze Inverter is showing a mains phase fault, you should: * Check wiring of the mains connection. * Check fuses.






Why does my Lenze i550 Inverter show a mains phase fault and how to fix it?
If your Lenze Inverter is showing a mains phase fault, you should: * Check wiring of the mains connection. * Check fuses.
What to do if my Lenze Inverter shows 'DC bus voltage too low for switch-on'?
If your Lenze Inverter displays a message indicating that the DC bus voltage is too low for switch-on, you should: * Check mains voltage. * Check fuses. * Check mains settings.
What to do if my Lenze i550 Inverter shows continuous overcurrent?
If your Lenze Inverter displays a continuous overcurrent error, you should: * Check motor and wiring for short circuit. * Check brake resistor and wiring. * Check motor circuit (delta connection, star connection). * Check setting of the motor data.
How to resolve a Lenze i550 Inverter motor overcurrent issue?
To resolve a motor overcurrent issue: * Check the motor load. * Check the drive sizing. * Adapt the set error threshold (P353.01).
Why does Lenze i550 show a mains phase fault?
A mains phase fault in your Lenze Inverter can be caused by issues with the power supply. Check the mains connection wiring and inspect the fuses to ensure they are working correctly.
What does '24 V supply critical' mean on Lenze Inverter?
If your Lenze Inverter displays '24 V supply critical': * Check the optional external 24 V voltage supply (terminal X3/24E), if connected. * Check the mains voltage.
What to do if my Lenze i550 displays 'Device utilization (Ixt) too high'?
If your Lenze Inverter displays a message indicating that device utilization (Ixt) is too high, you should: * Check drive sizing. * Reduce maximum overload current of the inverter (P324.00). * In case of high mass inertias, reduce maximum overload current of the inverter (P324.00) to 150 %.
What to do if my Lenze i550 shows motor overtemperature?
If your Lenze Inverter indicates motor overtemperature, you should: * Check drive sizing. * Check motor thermal sensor and wiring (X109/T1 and X109/T2).
What causes i²*t overload (thermal state) in Lenze Inverter and how to fix it?
If your Lenze Inverter is showing an i²*t overload (thermal state) error, you should: * Check drive sizing. * Check machine/driven mechanics for excessive load. * Check setting of the motor data. * Reduce values for slip compensation (P315.01, P315.02) and oscillation damping (P318.01, P318.02).
What to do if my Lenze i550 Inverter displays a warning for DC bus overvoltage?
If your Lenze Inverter shows a warning for DC bus overvoltage, you should: * Reduce dynamic performance of the load profile. * Check mains voltage. * Check settings for braking energy management. * Connect brake resistor to the power unit and activate the integrated brake chopper. (P706.01 = 0: Brake resistance).
| Protection Class | IP20 |
|---|---|
| Overload Capacity | 150% for 60 seconds |
| Safety | STO (Safe Torque Off) |
| Voltage Range | 380 V to 480 V |
| Control Type | Vector control, V/f control |
| Communication Interfaces | CANopen, EtherCAT, PROFINET, Ethernet/IP |
| Mains Voltage | 3-phase 380 V to 480 V |
| Input Voltage | 3-phase 380 V to 480 V |
| Output Voltage | 0 to Mains Voltage |
| Frequency Range | 0 Hz to 300 Hz |
| Protection Features | Overcurrent, overvoltage, undervoltage, short circuit, overtemperature |
| Ambient Temperature | -10°C to 50°C |
Overview of the inverter's physical components and connections.
Specifies the intended use and limitations of the product.
Lists relevant safety and technical standards the product adheres to.
Outlines operator responsibilities regarding standards and directives.
Details requirements for safe and compliant product commissioning.
Information on the PROFINET firmware and its licensing.
Explains how to identify different product variants and their coding.
Defines the use of decimal separators in the documentation.
Explains the meaning and importance of safety instruction symbols and levels.
Essential safety precautions to prevent injury and damage.
Identifies hazards that remain after safety measures are applied.
Specifies approvals, standards, and environmental operating conditions.
Crucial considerations before and during mechanical installation.
Instructions for attaching the shield connection sheet to the mounting plate.
Provides dimensional data and assembly requirements for the inverters.
Specific preparation steps for connecting to an IT system.
Illustrates exemplary wiring for all voltage and power classes.
Guidelines for ensuring electromagnetic compatibility during installation.
Technical data and fusing for 1-phase, 120V connections.
Technical data and fusing for 1-phase, 230/240V connections.
Technical data and fusing for 3-phase, 230/240V connections.
Technical data and fusing for 3-phase, 400V connections.
Technical data and fusing for 3-phase, 400V connections.
Technical data and fusing for 3-phase, 480V connections.
Technical data and fusing for 3-phase, 480V connections.
Instructions and recommendations for connecting a brake resistor.
Details on the function and connection of control terminals.
Information on the relay output terminals and their specifications.
Details on the PTC input for motor temperature monitoring.
Configuration for various network communication protocols.
Critical safety information and requirements for functional safety.
Explanation and implementation of the Safe Torque Off (STO) function.
Steps for the first-time power-up and initial checks.
Key considerations and warnings during the commissioning process.
Explains the operation of the keypad and its keys for parameter control.
How to activate and use keypad control for motor operations.
A streamlined process for commissioning using terminal controls.
Detailed wiring and parameter configuration for terminal control.
Overview of key parameters and their grouping for efficient setup.
Commonly used parameters configurable as favorites for quick access.
Essential parameters for basic configuration and operation.
Parameters related to motor identification, calibration, and data.
Parameters for loading default settings and saving user data.
How to interpret and display error messages on the keypad.
A comprehensive list of error codes, their descriptions, classifications, and remedies.
Explains the meaning of the status LEDs for the inverter.
Information on how to obtain further support and product details.