Let's break down the issue with your PowerFlex 525 drive and motor stopping

Why the Delay in Faulting:
Motor OL (Overload) Fault (F007)

You are correct in your understanding of how the Motor OL works. It's thermal modeling. The drive is simulating the heating of the motor windings. It accumulates heat based on the current flowing through the motor and dissipates heat based on time. This is why there's a time delay before a fault. The one-minute delay aligns with how these thermal overload protections work.

Overload Trip Time

The F007 fault is due to the motor thermal overload protection tripping. The drive is designed to allow the motor to handle short-term overloads, simulating the motor's thermal capacity. The overload protection takes into account the motor's FLA (Full Load Amps) and the configured overload current setting (your 7 amps). The time it takes to trip is based on the percentage above the 7-amp threshold. A slight overload will take longer to trip than a significant overload.

Current Limit Not Faulting



Current Limit is NOT a Hard Fault

This is where your understanding needs to be adjusted. The Current Limit on the PowerFlex 525 is not designed as a hard fault trigger in the way you're expecting. It's primarily a current regulation or current foldback feature. Its primary function is to limit the current going to the motor, usually to protect the drive itself, NOT the motor. When the current reaches the limit, the drive will actively reduce the output voltage (and therefore the motor speed/torque) to keep the current at or below the setpoint. It will try to keep the motor running without faulting.

Current Limit Function

The current limit is designed to prevent the drive from tripping on overcurrent or potentially damaging itself during brief load spikes or acceleration. It's a "soft" way to control the motor. The Current Limit set lower than the motor OL may impact the motor performance as the drive will reduce power to keep current below the threshold.

Possible Causes and Troubleshooting Steps


Increased Load at Depth

The fact that the issue happens consistently at a specific depth strongly suggests a mechanical problem:

Blade Binding

Check the saw blade for dullness, damage, or incorrect tooth set. A binding blade will drastically increase motor load.

Material Resistance

Is the metal harder or thicker at that specific depth? Even slight variations can increase the load.

Mechanical Friction

Inspect the saw's mechanical components (bearings, gears, guides) for excessive friction or binding at the depth. Lubricate thoroughly.2.

Incorrect Motor OL Setting



Verify the motor nameplate FLA

Double-check that the motor's FLA is indeed 12.2 amps.

Motor OL Set Too Low

Your 7-amp motor OL setting is significantly lower than the FLA. It should be set at or slightly above the motor FLA. A typical setting would be 100%-115% of the motor FLA. Set it to 12.2 or 12.5 amps, for example. 7 amps is causing the drive to trigger the overload protection prematurely.
3.

Current Limit Interaction



Raise Current Limit

After correcting the Motor OL setting, increase the Current Limit. A typical value is 150% of the motor FLA. This will allow the motor to deliver full torque when needed.4.

Drive Hardware Problem (Less Likely but Possible)



Compare Drive Parameters

Carefully compare all parameters between the malfunctioning drive and one of the working drives. A misconfigured parameter could be contributing.

Check for Heat Sink Issues

Make sure the drive's heatsink is clean and that the fan (if equipped) is working properly. Overheating can cause unexpected behavior.

Troubleshooting Steps (in order)


Mechanical Inspection

Thoroughly inspect the saw blade and mechanical components as described above. This is the most likely cause.2.

Correct Motor OL Setting

Set the Motor OL parameter to match (or be slightly above) the motor's FLA (12.2 amps).
3.

Adjust Current Limit

Set the Current Limit to 150% of the motor FLA.4.

Monitor Motor Current

Use the PowerFlex 525's built-in monitoring features to observe the motor current during operation. See how close the current gets to the overload and current limit settings.5.

Swap Drives

If you suspect a faulty drive, temporarily swap it with one from a working saw (making sure the motor parameters are correct for the swapped drive). See if the problem follows the drive.6.

Check Motor Insulation

Perform a motor insulation resistance test (Megger test) to ensure the motor windings are not breaking down, which could cause excessive current draw.7.

Monitor Voltage

Check the incoming voltage supply to the drive. Voltage drops can cause the drive to work harder and draw more current.

Why is this happening on only one saw?

Even with identical setups, small differences in the saw's mechanical condition, blade sharpness, material properties, or even minor drive variations can be amplified.

Important Safety Note: Always disconnect power from the drive and motor before performing any mechanical inspections or adjustments. Consult the PowerFlex 525 user manual for detailed information on parameter settings and safety procedures. Flag for review