Lenze 8400 Inverter Debugging Guide

8 VFCplus: V/f square fans, pumps, variable torque

10 VFCplus: V/f can define custom features

11 VFCplusEco energy-saving V/f control

5.4 DC injection braking (DCB)

C00019: Automatic DCB threshold (default 3 rpm). When the speed setting value is lower than this value, direct current is automatically injected.

C00036: DC braking current (percentage, relative to C00022, default 50%).

C00106: Automatic DCB hold time (default 0.500 s).

Manual DCB can be triggered through digital input DI3 (Terminals 0 mode).

5.5 Slip Compensation (C00021)

Only used for V/f control to improve speed accuracy under load. Default 2.67%. Excessive slip compensation may lead to instability.

5.6 Switching frequency (C00018)

Choose a fixed or variable switching frequency (2-16 kHz). Variable switching frequency can reduce switching losses (min. Pv) under light loads, but may generate auditory noise. The factory setting is "8 kHz var./drive optimized".

Troubleshooting and Diagnosis

6.1 LED Status Indication

Two LEDs (DRV-RDY green, DRV-ERR red) are located below the front panel of the inverter:

DRV-RDY DRV-ERR device status parameter C00137 display

Slow flashing (about 3 seconds), ready to go ReadyToSwitchOn

Flashing (about 1.25s) off, powered on SwitchedOn

Normally on/off, operational enabled during operation

Constant flashing warning OperaEnabled (with warning)

Fault of constantly on/off

Slow flashing system malfunction SystemFault

6.2 Common Error Codes and Countermeasures

Common causes and solutions for incorrect code names

OC1 power part short circuit, motor cable short circuit, frequency converter and motor power mismatch, check motor wiring; Use allowed combinations; Reduce current loop dynamics

OC2 grounding fault motor phase line short circuit to ground, cable too long (>50m) causing leakage current inspection insulation; Increase the filtering time for ground fault detection (C01770=250ms)

OC5 Ixt overload frequency converter overload check load cycle; Increase the power of the frequency converter

OC6 motor overload (I ² × t): Long term overload of the motor reduces the load; Check Vmin boost (C00016)

Check the main power supply for phase loss or low voltage of the LU DC bus under voltage; Set C00142 auto start option

The excessive regenerative energy of OU DC bus overvoltage increases the braking resistance; Use regeneration unit

OH1 radiator overheating, high ambient temperature, blocked fan, clean fan and heat sink; Reduce the ambient temperature

Check the load when the instantaneous current of OC7 motor exceeds the limit of C00939 due to overcurrent; Reduce dynamic response

LP1 motor phase loss motor cable breakage or poor contact inspection U, V, W connection

Su02: One phase main power supply is missing. One phase of the three-phase power supply is faulty. Check the power supply wiring

PS01 has no memory module. The memory module is not inserted or has poor contact. Insert the module and clamp it tightly

6.3 Fault Reset

By terminal X4/RFR: When a fault exists, changing RFR from LOW to HIGH can reset (provided that the cause of the fault has been eliminated).

Using the keyboard: select device command C00002/19=1.

Through PC software: click the reset button.

Attention: Some faults require power off and then power on to clear (such as system fault dF series).

6.4 Common misoperation (motor not turning)

Possible causes and solutions for the phenomenon

The motor does not rotate, and the green LED flashing controller is prohibited (CINH). Check all prohibited sources displayed on C00158; Set RFR to HIGH

The motor does not rotate and displays "CINH". Automatic start is prohibited (C00142 bit0=1). RFR rising edge is required

The motor does not rotate, displaying "IMP" Quick Stop (QSP) activation check C00159 shows QSP source

Motor shaking or irregular rotation motor cable phase sequence error (feedback system does not match motor rotation direction), exchange motor two phases; Check the encoder wiring (if any)

Advanced Features and Applications

7.1 Speed Limitation and Frequency Hopping

C00635: Maximum speed set point limit (%). C00636: Minimum speed set point limit.

Skip Frequency: Used to avoid mechanical resonance points. Define three hopping zones using C00632/x (maximum hopping value) and C00633/x (minimum hopping value). When the set value enters the zone, the output speed remains at the previous value until the set value leaves the zone.

7.2 Motor Potentiometer

The motor potentiometer function replaces the hardware potentiometer and adjusts the speed through two digital inputs (speed up/down). Activation method:

Set C00806=1 (enabled), or enter bMPotEnable through the process (requires configuration).

Upper and lower limits: C00800 (upper limit, default 100%), C00801 (lower limit, default 0%).

Acceleration and deceleration time: C00802, C00803.

Initialization behavior after power failure: C00805.

7.3 Process Controller (PID)

Process controllers can be used for tension control, pressure control, position control, etc. The operating mode is selected by C00242:

0: Close

1: Main setting+PID output

2: PID output as the main setting (actual value feedback)

3: PID output as the main setting (actual value feedback, another structure)