OMRON 3G3KV frequency converter

6. DC braking (constant No. 26-28)

Used for precise positioning during stopping or for "capturing" a freely rotating motor before starting.

No.26: DC braking current (0-100%, 100% is equal to the rated current of the frequency converter). 50% factory production.

No.27: DC braking time at stop (0.0-25.5 seconds). 0.5 seconds from factory.

No.28: DC braking time during startup (0.0-25.5 seconds). 0.0 seconds from factory (disabled).

7. Carrier frequency (constant No.40)

Affects motor noise, frequency converter self loss, and external interference. Set range 1-6, corresponding to 2.5kHz to 15kHz (formula: 2.5kHz x set value). The factory output is 4 (10kHz).

Long line drive: When the distance between the frequency converter and the motor exceeds 30 meters, the carrier frequency must be reduced (such as ≤ 10kHz within 50 meters and ≤ 5kHz within 100 meters).

Reduced usage: When the carrier frequency is set to 5, the continuous output current needs to be reduced to 90%; When set to 6, it needs to be reduced to 80%.

Digital operator: the core tool for on-site debugging

The 3G3KV digital operator is a human-machine interface for parameter setting, operation monitoring, and fault diagnosis. The key operating modes include:

DRIVE Mode: Run mode. Can start/stop, jog, and change frequency settings.

PRGM Mode: Programming Mode. Used to modify all constants.

Key operation example:

Modify parameters: Press the PRGM/DRIVE key to enter PRGM Mode → use the NO/DSPL key to select a constant number → use the up and down keys to modify the value → press the DATA/ENTER key to write. The screen displays' END 'to indicate successful writing.

Monitoring: Press the NO/DSPL key in DRIVE Mode to cycle through the display: frequency given → output frequency → output current → fault content.

Fault reset: After a fault occurs, press the>/RESET key or input a reset signal through external terminal 3.

Parameter initialization: Setting the constant No.00 to 8 can restore all parameters to their factory values.

Troubleshooting: Systematic Diagnostic Process

3G3KV has comprehensive protection functions, and correctly interpreting fault codes is the key to quick repair.

Common fault codes and troubleshooting steps

Common causes and corrective measures for fault display protection function

U1 (UV1) low voltage protection power supply has insufficient capacity, large line voltage drop, and a large motor starting in the same power grid. Check the power capacity and wiring. When the signal input is turned off during operation, UV will be triggered. The frequency converter should be stopped first before turning off the power.

The overcurrent protection of α C (OC) includes rapid acceleration and deceleration, short circuit or grounding on the output side, and excessive motor capacity. Extend the acceleration and deceleration time. Check the output wiring. Confirm that the capacity of the motor matches that of the frequency converter.

The deceleration time of the α U (OV) overvoltage protection is too short, and the load has regenerative energy (such as being pulled backwards by the load). Extend the deceleration time. Optional braking resistor.

OL1 (OL1) motor overload, low-speed long-term operation, improper V/f characteristic setting. Reduce the load. Optimize the operating mode. Check the V/f settings.

The OL2 frequency converter is overloaded with excessive load and has a short acceleration time. Reduce the load. Extend acceleration time. Consider increasing the capacity of the frequency converter.

OL3 (OL3) over torque detection mechanical failure caused the current to exceed the preset detection level. Check the mechanical parts (if stuck). Appropriately increase the torque detection level (No.38).

GF grounding fault: The output side of the frequency converter is grounded. Check the insulation of the motor and output cables.

Overheating of the OH radiator, malfunction of the cooling fan, high ambient temperature, and clogged filter. Replace the fan. Clean the filter. Ensure that the ambient temperature is below 40 ° C.

CPF00-05 control circuit fault external noise, vibration, component failure. Record the fault code and attempt initialization. Power off and restart. If the fault persists, the frequency converter needs to be replaced.

Special functions and warning prompts

Stall prevention: This is not a malfunction, but a protective action. When the current during acceleration exceeds 170%, the frequency converter will pause acceleration and wait for the current to fall back; When the DC voltage is too high during deceleration, the deceleration will be paused. This is a normal phenomenon, indicating that the load inertia is too large or the acceleration and deceleration time is set too short.

EF: If both forward and reverse commands are inputted simultaneously for more than 500ms, the frequency converter will stop in the preset way. Check the setting of control timing or constant No.32 (such as whether it is mistakenly set to 3-Wire mode).

BB: External base block signal input, motor stops sliding freely. Check the input status of external terminals 4/5.

Maintenance and testing