MONARCH NICE3000 Error Codes: Complete Fault List, Causes & Troubleshooting Guide

An elevator inverter, also known as an elevator variable frequency drive (VFD), controls motor speed and torque to support smooth acceleration, constant-speed operation, and deceleration.

When the inverter detects an abnormal operating condition, it may generate a fault code and stop or restrict operation to protect the drive and connected equipment.

However, a fault code does not always identify a single failed component. Several conditions can produce similar symptoms, so technicians should evaluate the complete system rather than replacing parts based solely on the displayed code.

The following sections summarize common MONARCH NICE3000 fault codes, their potential causes, and troubleshooting recommendations. Exact definitions and troubleshooting procedures may vary depending on the inverter manufacturer, controller model, and version.

Overcurrent faults occur when the MONARCH NICE3000 elevator inverter detects excessive current during a particular operating stage.

• Err02 – Acceleration Overcurrent: The inverter detects excessive current during acceleration.
• Err03 – Deceleration Overcurrent: Excessive current occurs during deceleration.
• Err04 – Constant-Speed Overcurrent: Excessive current is detected while the elevator is running at a relatively stable speed.

Common Causes

Potential causes of NICE3000 overcurrent faults include:

• Ground faults or short circuits in the main output circuit.
• Incorrect motor parameter identification or tuning.
• Incorrect encoder signals or feedback abnormalities.
• Incorrect motor phase sequence.
• Acceleration time that is too short.
• An excessively steep deceleration curve.
• Excessive mechanical resistance or abnormal motor loading.

Troubleshooting Recommendations

First, inspect the motor cables, output terminals, and insulation condition for possible short circuits or ground faults. Next, verify the motor parameters and encoder feedback configuration. If the electrical connections and feedback signals are normal, review the acceleration and deceleration settings.

For Err04, technicians should also assess whether the motor is operating under excessive load or experiencing abnormal mechanical resistance.

Important: Do not assume that a MONARCH NICE3000 overcurrent fault always indicates a defective inverter. Motor tuning, encoder feedback, wiring, and mechanical conditions should also be investigated.

Bus overvoltage faults indicate that the NICE3000 elevator inverter's DC bus voltage has exceeded its permitted operating range.

The fault code often identifies the operating stage in which the abnormal voltage was detected.

• Err05 – Acceleration Bus Overvoltage: Bus voltage rises beyond the permitted limit during acceleration.
• Err06 – Deceleration Bus Overvoltage: Bus voltage exceeds the permitted limit during deceleration.
• Err07 – Constant-Speed Bus Overvoltage: Bus overvoltage is detected during constant-speed operation.

Common Causes

Possible causes of NICE3000 bus overvoltage faults include:

• Excessively high input voltage.
• An incorrectly selected braking resistor.
• A malfunctioning braking unit.
• Excessive acceleration or deceleration settings, where applicable.
• Abnormal power supply conditions.

During deceleration, the motor may regenerate energy back into the drive. If the regenerative energy cannot be dissipated or managed adequately, the DC bus voltage may rise and trigger an overvoltage fault.

Troubleshooting Recommendations

Measure the input voltage and compare it with the inverter's specified operating range. Inspect the braking resistor, braking unit, and associated wiring. If the fault occurs mainly during deceleration, review the deceleration profile and regenerative braking arrangement.

Any adjustment to braking parameters or hardware must follow the inverter manufacturer's specifications and the elevator system's approved configuration.

Err09 – Bus Undervoltage indicates that the MONARCH NICE3000 elevator inverter's DC bus voltage has fallen below its permitted threshold.

Common Causes

• Momentary interruption of the input power supply.
• Input voltage that is too low.
• Unstable or abnormal power supply conditions.
• A faulty inverter control board or related internal circuitry.

Troubleshooting Recommendations

Check the incoming power supply and measure voltage under appropriate operating conditions. Inspect the supply connections and investigate whether the fault coincides with power interruptions or voltage fluctuations.

If the external power supply is stable but the NICE3000 undervoltage fault persists, further inspection of the inverter's internal power and control circuits may be necessary.

These MONARCH NICE3000 fault codes may be related to excessive load, incorrect motor configuration, unstable power input, or problems with the motor output circuit.

Err10 – Drive Overload

Potential causes include:

• Excessive mechanical resistance.
• An inappropriate elevator balance coefficient.
• Abnormal encoder feedback.
• Inaccurate motor tuning, resulting in excessive operating current.
• Incorrect motor phase sequence.
• An inverter whose capacity is insufficient for the application.

Technicians should inspect the elevator's mechanical condition, assess the load and balance configuration, verify encoder feedback, and confirm that the inverter is appropriately rated for the motor and application.

Err12 – Input Phase Loss

This fault indicates a problem associated with the NICE3000 inverter's input power phases.

Possible causes include an unbalanced input power supply, a missing phase, poor electrical connections, or an abnormal inverter control board.

Inspect the incoming supply and terminals, and verify phase balance and continuity using appropriate electrical test procedures.

Err13 – Output Phase Loss

Potential causes include loose motor output wiring, an interrupted phase connection, or motor damage.

Inspect the connections between the inverter and motor, paying particular attention to loose terminals, damaged cables, and abnormal motor winding conditions.

Electrical measurements and continuity checks should be performed only by qualified personnel using procedures appropriate for the equipment.

Err14 – Module Overheating

An inverter module overheating fault indicates that the power module temperature has exceeded its permitted limit.

Common causes include:

• Excessively high ambient temperature.
• Insufficient ventilation or blocked airflow.
• Cooling fan failure.
• Dust accumulation on heat sinks or ventilation passages.
• Excessive load or operating conditions that increase heat generation.

Check the installation environment, ventilation, cooling fan operation, and heat sink condition. Also investigate whether the inverter is operating within its specified duty and load limits.

Err15 – Brake Resistor Short Circuit

This fault category may indicate a short circuit in the braking resistor or a fault involving the braking IGBT.

Recommended inspection points for this NICE3000 braking circuit fault include the braking resistor, wiring, terminals, and braking circuit components.

Before inspecting or replacing braking components, isolate the power supply and follow the manufacturer's discharge and electrical safety procedures. The DC bus may retain a dangerous voltage even after the input power has been disconnected.

These MONARCH NICE3000 error codes can indicate problems with current regulation, hardware signal detection, encoder feedback, or motor parameter identification.

Err16 – Current Control Error

Potential causes include excessive excitation-current deviation or excessive torque-current deviation.

Technicians should verify the motor configuration, parameter settings, feedback signals, and current-control conditions. Persistent faults may require inspection of the inverter's current detection or control circuitry.

Err17 – Encoder Abnormal During Tuning

This fault is associated with abnormal sine/cosine encoder signals during motor tuning.

Check encoder wiring, connectors, signal integrity, and compatibility with the inverter's feedback interface.

Err18 – Hardware Signal Detection Error

Possible causes include excessive hardware zero drift or a product identification signal fault.

If external wiring and configuration are correct, further diagnosis of the drive's internal detection circuitry may be required.

Err19 – Motor Tuning Error

Motor tuning faults may occur when the inverter cannot complete motor parameter identification successfully.

Depending on the fault subtype and drive configuration, potential causes include:

• Failure to identify stator resistance.
• Failure to identify the magnetic pole position.
• Excessive CD signal fluctuation during synchronous motor static tuning.
• An incorrect encoder phase sequence during static tuning.
• Failure to obtain the required angle in an angle-free self-learning mode.
• Tuning that exceeds the permitted completion time.

Troubleshooting Recommendations

Confirm that the motor type and rated parameters have been entered correctly. Check encoder wiring, signal compatibility, motor phase connections, and the conditions required for the selected tuning procedure.

For synchronous motors, verify that the encoder and motor configuration match the manufacturer's requirements. Some tuning procedures require specific mechanical conditions, so technicians must follow the relevant drive manual rather than applying a universal procedure.

Err20 – Speed Feedback Error covers several conditions related to encoder signals, speed feedback, motor direction, and speed-control performance in the NICE3000 elevator inverter.

Depending on the drive's specific fault subtype, the displayed code may indicate:

• An encoder signal that cannot be detected during synchronous motor no-load tuning.
• A missing Z signal during motor identification.
• A disconnected SIN/COS encoder signal.
• Loss of the Z signal during normal operation.
• Incorrect motor phase sequence or motor wiring.
• Overspeed.
• Excessive speed deviation when the torque limit is reached.
• Loss of encoder AB signals during startup or operation.
• Severe interference affecting sine/cosine encoder signals.
• Encoder signal interference or an incorrect CD signal during tuning.

Why Encoder Feedback Matters

The encoder provides position or speed feedback that helps the inverter control motor movement. Incorrect, missing, or unstable feedback can interfere with motor startup, speed regulation, and position-related control functions.

However, not every NICE3000 Err20 subtype indicates a defective encoder. Incorrect wiring, electrical interference, configuration errors, motor phase sequence, or mechanical operating conditions may also contribute.

Troubleshooting Recommendations

1. Identify the exact Err20 subtype shown on the inverter display or fault history.
2. Inspect the encoder cable, connectors, shielding, and grounding arrangement.
3. Verify the encoder model, signal type, and wiring against the inverter documentation.
4. Check for missing or unstable AB, Z, SIN/COS, or CD signals as applicable.
5. Confirm the motor phase sequence and encoder direction configuration.
6. Investigate possible electrical interference and verify that the feedback cable is installed according to the manufacturer's requirements.

Encoder-related faults should be diagnosed carefully because incorrect feedback configuration or inappropriate adjustments can affect elevator motion and safety.

The following table provides a concise reference for the NICE3000 elevator inverter fault codes discussed in this guide.

Note: This table is a general troubleshooting reference based on the fault descriptions covered in this article. The exact meaning of a code or subcode may differ by inverter series, firmware, and manufacturer. Always consult the corresponding technical manual before performing corrective actions. 

When an elevator inverter reports a fault, a structured diagnostic process can help technicians identify the cause more efficiently and avoid unnecessary component replacement.

Step 1: Record the Fault Information

Record the complete fault code, any associated subcode, the operating stage, and the conditions under which the fault occurred. Check the fault history if the drive supports it.

Step 2: Inspect the Power Supply and Wiring

Check the input supply, motor output connections, terminals, and relevant cables. Look for loose connections, damaged insulation, phase imbalance, or other abnormalities.

Step 3: Verify Motor Parameters and Feedback

Confirm that the motor parameters and tuning settings are correct. Inspect encoder compatibility, wiring, signal quality, and configuration.

Step 4: Check Mechanical and Operating Conditions

Investigate abnormal mechanical resistance, excessive loading, elevator balance, and acceleration or deceleration settings where relevant.

Step 5: Inspect the Braking and Cooling Systems

For overvoltage or braking-related faults, inspect the braking resistor and braking unit. For overheating faults, examine ventilation, cooling fans, and operating temperature.

Step 6: Evaluate the Inverter Hardware

If external wiring, power supply, motor configuration, and operating conditions are verified but the fault persists, qualified technicians may need to inspect the inverter's internal power or control circuits.

Elevator equipment should not be returned to service until the fault has been properly diagnosed, corrective action has been verified, and the system has passed the required safety checks.