What you are seeing
The drive runs for a while, then throws a code and stops the motor. Sometimes it trips the instant you hit start, sometimes only under load, sometimes hours into a shift with no obvious trigger. You reset it, it runs again, and a little later you are back where you started. On a conveyor or a pump that means the line stops with it, and the reset dance gets old fast.
The most common fault families you will see on the display are overcurrent, overvoltage, overheat, and ground fault. Each one points in a different direction, so the code on the screen is your first and best clue. Write it down exactly, along with whether it trips at start, at speed, or only under load.
Common causes, and where each one points
Usually a mechanical or motor problem, not the drive. A jammed conveyor, a seized bearing, a load the drive is trying to accelerate too fast, or a shorted or grounded motor winding will all pull current the instant it tries to spin. If it trips before the motor even turns, look at the mechanical load and the motor, not the parameters.
The motor and drive are working harder than they are sized or tuned for. A worn mechanical drivetrain, a clogged pump, an undersized drive, or an acceleration ramp set too aggressive will all show up as an overload once the work starts. Overload trips that get more frequent over weeks usually mean something is wearing.
A fast stop on a high inertia load feeds energy back into the drive, and with nowhere for it to go the bus voltage climbs until the drive trips to protect itself. That points to the deceleration ramp being too short for the load, or a missing or failed braking resistor.
The drive is cooking. Blocked cooling fins, a dead cooling fan, a clogged filter, an enclosure with no ventilation, or a South Florida panel sitting in the heat with the door shut will all push a drive over its thermal limit. This one is often the cheapest to fix and the easiest to miss.
A drive that was swapped in but never programmed for your specific motor and load will trip on defaults that do not match your equipment. Motor nameplate data, current limits, and acceleration settings all have to be set for the machine the drive is actually running.
These point at the wiring between the drive and the motor, or at the motor itself. A nicked conductor, moisture in a junction box, or a motor winding breaking down to ground will all show here. This is where you stop and treat it as a real electrical fault.
What you can check safely
Safety first. A running drive holds a dangerous charge on its DC bus even after power is removed. Do not open a drive or land wires unless you are qualified and it is fully de-energized and verified. The items below are the safe, useful things an operator or maintenance lead can check first.
- 1 Read the exact fault code off the display and note whether it trips at start, at speed, or on stop. That one detail cuts the problem in half.
- 2 Turn the driven equipment by hand if it is safe to do so. If a conveyor, pump, or fan is stiff, dragging, or seized, the drive is doing its job by tripping.
- 3 Feel and look at the drive and enclosure. Is the cooling fan spinning, are the fins caked with dust, is the panel sitting in direct heat with the door closed?
- 4 Check whether the trips started after any change: a new drive, a motor swap, a mechanical repair, a production speed increase, or hot weather.
- 5 Look for the obvious at the motor: burning smell, discoloration, moisture, or a nameplate that does not match what the drive is set to.
- 6 Note the pattern. Every start, only under full load, only on a fast stop, or random. Bring that pattern when you call, it saves diagnostic time.
When to call a pro
If the drive trips on ground fault, on an output phase fault, or right at start with a burning smell or discoloration at the motor, stop resetting it. Repeated resets into a real electrical fault can turn a repairable motor or a good drive into a replacement. That is the point to bring someone in to test the motor windings, the drive output, and the wiring properly.
You also want help when the trips are intermittent and you cannot tie them to a pattern, when the drive was replaced but never set up for your motor, or when the fault is overvoltage on a hard stopping load and you are not sure whether you need a braking resistor or just a longer ramp. Those are diagnosis, not parts swaps, and guessing gets expensive.
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