This troubleshooting guide provides practical steps for identifying common problems in Electromen motor controller applications.
Some problems and diagnostic procedures are different for Brushed DC motors and Brushless DC motors (BLDC). Where relevant, the instructions below clearly identify the motor type.
Important: Product features, protection functions, parameter numbers and electrical ratings vary between Electromen products. Always refer to the product-specific datasheet and user manual.
Diagnostic hint: A BLDC motor that does not start but draws significant current often indicates an incorrect or missing Hall signal, incorrect phase/Hall combination or a mechanically blocked motor.
↑ Back to Troubleshooting Guide
Check:
A worn brush or damaged commutator can cause irregular torque, electrical noise and unstable operation.
Rough operation combined with unusually high current is a strong indication that the motor phase sequence and Hall sensor sequence may not correspond.
Check:
Important: Do not continue operating a BLDC motor with incorrect commutation. Incorrect phasing can produce high motor and controller current.
↑ Back to Troubleshooting Guide
Check the motor resistance, brush condition, commutator and mechanical load. A damaged armature or commutator can increase current consumption.
Incorrect Hall/phase phasing is one of the first items to check if a BLDC motor draws high current while producing poor torque or rough rotation.
↑ Back to Troubleshooting Guide
Rotation direction is determined by motor polarity. Electromen controllers normally provide electronic direction control, so use the controller Direction input or command where available.
After correct Hall and phase commutation has been established, use the controller Direction command to reverse rotation.
Do not randomly exchange BLDC phase wires to reverse direction, because the Hall sensor sequence must remain correctly matched to the phase sequence.
↑ Back to Troubleshooting Guide
I-Trip indicates that motor current has remained at or above the configured current limit for longer than the permitted time.
Do not increase the current limit simply to eliminate an I-Trip fault without first identifying why excessive current is present.
↑ Back to Troubleshooting Guide
Measure the supply voltage while the motor is operating. A supply that appears correct without load may drop significantly when motor current increases.
If the controller is operating at the current limit, the motor may not have sufficient available torque to accelerate to the requested speed.
↑ Back to Troubleshooting Guide
Measure the DC supply directly at the controller during acceleration, deceleration and direction changes. Short voltage disturbances may not be visible when measuring only the unloaded supply.
↑ Back to Troubleshooting Guide
When a motor decelerates, mechanical energy can be returned to the DC supply. This is called regenerative braking.
A suitable battery may absorb regenerative energy, provided that the battery, BMS and charging system permit reverse charging current.
Many standard DC power supplies cannot absorb reverse current. Regenerative energy can therefore raise the DC bus voltage.
↑ Back to Troubleshooting Guide
The controller current rating must always be considered together with the specified cooling conditions.
↑ Back to Troubleshooting Guide
Motor copper losses increase approximately with the square of current:
PLOSS ≈ I2 × R
A relatively small increase in motor current can therefore cause a significant increase in heating.
Incorrect commutation can cause excessive heating even when mechanical output power is low. Check Hall and phase phasing if the BLDC motor runs hot and roughly or draws unexpectedly high current.
↑ Back to Troubleshooting Guide
In open-loop operation, motor speed can change with load and supply voltage. Some variation is therefore normal.
Check:
If the speed command itself is unstable, check:
↑ Back to Troubleshooting Guide
This section applies specifically to BLDC motors.
A typical sensored BLDC motor uses three Hall signals. During rotation, the Hall states should change in a valid sequence.
Check:
The three motor phase wires and three Hall signals must form a compatible commutation combination.
If the motor runs roughly or draws high current after wiring changes, stop the motor and verify the combination before continuing.
↑ Back to Troubleshooting Guide
This section applies specifically to BLDC motors.
If electrical performance is clearly different between forward and reverse operation, verify the Hall signals and commutation phasing before adjusting current limits.
↑ Back to Troubleshooting Guide
This section applies specifically to brushed DC motors.
A brushed DC motor performs commutation mechanically using brushes and a commutator.
Motor brush and commutator faults cannot normally be corrected by changing controller parameters.
↑ Back to Troubleshooting Guide
Check the dead zone, braking area and load compensation. Also inspect the mechanical system for backlash and elasticity.
Check whether friction is preventing final movement or whether the braking area is too large.
Check braking area, approach speed, mechanical inertia and load compensation.
↑ Back to Troubleshooting Guide
If the controller detects a mechanical end using motor current, the current limit and mechanical load must allow reliable end detection.
For systems using external limit or reference signals, verify the state and polarity of those signals.
↑ Back to Troubleshooting Guide
Measure the control voltage directly between the controller analog input and its signal ground.
↑ Back to Troubleshooting Guide
Many Electromen products allow digital input functions to be changed by parameters. Always verify what function is currently assigned to the input.
If several commands are active simultaneously, check the input priority described in the product manual.
↑ Back to Troubleshooting Guide
Check:
Check:
This strongly suggests checking EMC installation.
Start troubleshooting with one controller and a short RS-485 cable. Once communication works reliably, add other devices one at a time.
↑ Back to Troubleshooting Guide
Many Electromen status outputs are transistor outputs such as NPN open collector outputs. They do not behave like voltage-source outputs.
Verify:
On configurable products, the same output may be assigned to indicate different conditions such as:
Verify the output configuration before assuming that the output itself is faulty.
↑ Back to Troubleshooting Guide
| Symptom | Brushed DC – Check First | BLDC – Check First |
|---|---|---|
| Motor does not start | Supply, commands, brushes, motor wiring | Supply, commands, Hall signals, phase wiring |
| Motor runs roughly | Brushes, commutator, load, supply | Hall/phase phasing |
| High motor current | Mechanical load, motor condition | Hall/phase phasing, mechanical load |
| Poor starting torque | Current limit, supply, motor | Current limit, Hall phasing, supply |
| I-Trip during acceleration | Load, ramp, current limit | Load, ramp, current limit, phasing |
| Overvoltage during stop | Regeneration, stop ramp, braking resistor | Regeneration, stop ramp, braking resistor |
| Controller overheats | Current and cooling | Current, cooling and correct commutation |
| Speed fluctuates | Supply, command signal, load | Feedback, Hall signals, command signal |
↑ Back to Troubleshooting Guide
Providing the following information can significantly speed up troubleshooting:
A clear description of what was expected to happen and what actually happened is often one of the most useful pieces of troubleshooting information.
This troubleshooting guide provides general engineering guidance and does not replace product-specific technical documentation.
Disconnect or isolate power before changing wiring where required. Motor controllers can produce high currents, unexpected motor movement and hot components. Braking resistors can reach high surface temperatures.
Electrical ratings, protection thresholds, parameter numbers, I/O functions, Hall sensor interfaces and communication settings vary between Electromen products.
Always refer to the datasheet and user manual of the specific Electromen controller before changing wiring or parameters.
Electromen motor controllers are components intended for integration into a complete machine or system. The system designer or integrator is responsible for correct installation and for compliance of the complete system with applicable electrical, EMC and safety requirements.
