VUKAR Motor Starter Fault Codes: FOL, FDR, HIU, LOU & SPP Meaning and Reset Guide

When a VUKAR motor starter or controller displays FOL, FDR, HIU, LOU, or SPP, the code identifies the protection state detected by the controller. It does not by itself confirm the underlying mechanical, electrical, water-supply, or installation problem. Use the code as the starting point for a safe diagnosis—not as proof of a specific root cause.

Compatibility notice: This guide applies only to VUKAR motor starters or controllers that actually display the relevant fault code. Fault availability and reset behaviour may vary by model and configuration. This article does not claim universal compatibility or provide an exact model compatibility matrix. Confirm your model using the VUKAR Product Manual or VUKAR support before acting.

After any permitted reset, allow only one controlled restart. If the same fault returns, stop the equipment and escalate the diagnosis.

Quick fault-code reference table

Code	Verified meaning	Likely condition—not a confirmed diagnosis	Verified reset behaviour
FOL	Overload	Motor current remained above the configured overload threshold for the configured trip delay	Hold MENU for 2 seconds. Power-cycle reset is available only when OLM is disabled.
FDR	Dry Run	Running current remained below the configured dry-run threshold for the applicable delay	Hold MENU for 2 seconds, power cycle, or allow the applicable RST timer to complete when Cyclic Timer and RST are enabled.
HIU	Overvoltage	Input voltage is above the active configured high-voltage limit	Automatic clearing when voltage returns within the configured LOU–HIU range. Manual reset is not supported.
LOU	Undervoltage	Input voltage is below the active configured low-voltage limit	Automatic clearing when voltage returns within the configured LOU–HIU range. Manual reset is not supported.
SPP	Phase Failure, Phase Loss, or Phase Sequence	The controller detected the applicable phase-protection condition	Switch off the mains supply first, then interchange the R & Y input phase wires. Alternatively, wait until all phases are restored.

Before resetting any VUKAR fault

A reset clears a detected protection state; it does not prove that the cause has been removed. Repeated resetting can expose a motor, pump, cable, supply, or starter to further stress. HIU and LOU can clear automatically, and some FDR and FOL configurations may also restart automatically. Keep people, tools, and loose materials away from moving equipment whenever automatic recovery is possible.

Before a user-level reset:

1. Read and record the displayed code.
2. Isolate the supply if an inspection requires opening a panel, touching conductors, or approaching moving machinery.
3. Check only safe external conditions, such as whether the water source is available, visible ventilation is blocked, or the supply appears unstable.
4. Confirm the exact controller model and the permitted reset method in its manual.
5. Allow one controlled restart only after the cause has been assessed.

Do not open the panel, move phase conductors, change protection parameters, bypass a trip, or test live terminals unless you are a qualified technician using the correct isolation and verification procedure.

FOL: Overload

FOL means Overload. On applicable VUKAR controllers, the state is associated with motor current remaining above the configured overload threshold for the configured trip delay. That describes the controller’s trigger logic; it does not identify a single cause.

Possible causes can include excessive mechanical load, a jammed pump, supply problems, incorrect settings, damaged cabling, motor trouble, or an installation issue. These are diagnostic possibilities rather than conclusions. A technician should compare the displayed current, configured threshold, motor nameplate, wiring, and actual load before changing any setting.

The verified manual reset is to hold MENU for 2 seconds. A power-cycle reset is available only when OLM is disabled. If OLM is enabled, do not present power cycling as a universal FOL reset. Automatic-restart behaviour depends on the model and configuration, so clear the area before restoring power.

If FOL returns after one controlled restart, stop. Repeated overload operation can damage equipment, and the underlying current or load condition requires diagnosis.

FDR: Dry Run

FDR means Dry Run. On applicable units, it is associated with running current remaining below the configured dry-run threshold for the applicable delay. Low current may be consistent with loss of water or reduced pump load, but the code alone does not prove that a borewell, tank, suction line, sensor, pump, or pipe is dry or defective.

Check safe external water-supply conditions first. A qualified technician may then verify the current reading, dry-run threshold, delay, motor load, pump condition, and installation against the exact manual.

Verified clearing methods are:

• Hold MENU for 2 seconds.
• Power cycle the applicable controller.
• When Cyclic Timer and RST are enabled, allow the configured RST timer to complete.

The timer path means the equipment may restart without another manual command. Keep the pump and connected machinery in a safe state during the waiting period. If FDR returns after one controlled restart, stop and diagnose the water supply, pump load, wiring, and settings rather than repeatedly clearing the code.

HIU and LOU: Voltage faults

HIU means Overvoltage: the input voltage is above the active configured high-voltage limit. LOU means Undervoltage: the input voltage is below the active configured low-voltage limit. The configured limits are part of the controller setup and should not be changed merely to suppress a fault.

For applicable models, HIU and LOU clear automatically after the measured voltage returns within the configured LOU–HIU operating range. Manual reset is not supported for these faults. Because recovery is automatic, the connected motor may become ready to run when the supply normalises.

Do not use repeated power cycling as a substitute for supply diagnosis. If HIU or LOU persists, a qualified technician should check the incoming voltage, phase conditions where applicable, connections, conductor sizing, supply stability, and the exact configured limits against the model manual. Work on live supplies or inside panels requires appropriate qualification, isolation, and test equipment.

SPP: Phase Failure, Phase Loss or Phase Sequence

SPP is used for the applicable phase-protection condition and may be described as Phase Failure, Phase Loss, or Phase Sequence in VUKAR evidence. The displayed code tells you that the controller detected a phase-related protection state; it does not by itself identify the failed conductor, supply fault, terminal problem, or installation error.

The correction is to switch off the mains supply, then interchange the R and Y input phase wires. Never do this with the supply live. If the cause is a lost phase rather than a reversed sequence, rewiring will not help — wait until all three phases are restored by the supply.

Isolate the supply and verify it is dead before opening the panel or touching any conductor. If you are not confident doing that safely, this is work for a qualified electrician. For suitable equipment categories, see Three Phase Motor Protection Devices, then confirm the selected product’s manual and support guidance.

Safe reset decision workflow

Use this workflow for any of the listed codes:

1. Identify the code and model.
   • Record the exact code.
   • Read the controller label and confirm the model manual.
2. Classify the recovery behaviour.
   • FOL and FDR have permitted manual clearing paths on applicable models.
   • HIU and LOU clear automatically when voltage returns to range.
   • FDR and some FOL configurations can have automatic-restart behaviour.
3. Make the area safe.
   • Keep people and tools away from the pump, motor, coupling, and moving machinery.
   • Isolate and verify de-energization before any panel or conductor work.
4. Check only conditions within your competence.
   • Users may review safe external conditions and the displayed information.
   • Any work inside the panel — measurements, wiring, phase interchange, protection settings — requires the supply isolated and verified dead first.
5. Use only the verified reset path for the exact model.
6. Allow one controlled restart.
7. Stop and escalate if the code returns.

This sequence avoids treating reset as a repair and makes automatic recovery an explicit safety consideration.

When resetting is not enough

Stop resetting and arrange a qualified diagnosis when:

• The same fault returns after one controlled restart.
• FOL is accompanied by abnormal noise, heat, smell, vibration, or stalled equipment.
• FDR repeats despite an apparently available water source.
• HIU or LOU persists or the supply is visibly unstable.
• SPP returns after the R and Y phases have been interchanged with the supply switched off.
• A fuse, breaker, cable, contactor, terminal, motor, or pump shows visible damage.
• The exact model, settings, or permitted reset method cannot be confirmed.

Never bypass protection, raise or lower thresholds simply to keep the motor running, or assume a replacement product is compatible because it appears in the same category. Use Product Selection as a selection aid, then confirm the application with VUKAR support.

FAQs

What does FOL mean on a VUKAR starter?

FOL means Overload. It indicates that current exceeded the configured overload threshold for the configured delay on an applicable controller. It does not confirm why the current was high.

Can I reset FOL by switching the power off and on?

Only when OLM is disabled on the applicable configuration. Holding MENU for 2 seconds is the verified manual reset. Confirm the exact model manual before acting.

What does FDR mean?

FDR means Dry Run. The controller detected current below the configured dry-run threshold for the applicable delay. Treat water loss or reduced pump load as possibilities to investigate, not as a diagnosis proven by the code.

Do HIU and LOU need a manual reset?

For applicable VUKAR models covered by this guide, HIU and LOU use automatic fault clearing after the supply returns within the configured operating range. Confirm the exact model manual because restart behaviour can vary by configuration.

Can I correct SPP myself?

SPP indicates a phase-related protection condition. Where it is a phase-sequence problem, the fix is to switch off the mains supply and interchange the R and Y input phase wires. Never attempt this with the supply live, and if a phase is missing from the supply rather than reversed, wait for it to be restored. If you are not confident isolating the panel safely, call a qualified electrician.

Identify your exact model and get the correct support

Start with the VUKAR Product Manual. For category-level browsing, use Single Phase Motor Protection Devices or Three Phase Motor Protection Devices. These category links do not claim that every listed product displays every code.

For application help, use Product Selection or contact VUKAR support. Provide the exact model, supply type, motor rating, displayed code, configured values, and what happened before the trip. Do not publish or act on model compatibility assumptions without confirmation.