INVT

INVT Elevator Drive Technical Service

INVT elevator drive technical service includes fault diagnosis of the inverter/drive unit, repair of the power board along with control and power supply circuits, necessary component replacements, cooling and connection inspections, and most importantly, testing under the motor to safely restore it to the field. Merely having the drive display on the screen or switching to the “RUN/READY” status is not considered sufficient. Many issues arise during cabin load, deceleration–braking moments, grid fluctuations, or when the control panel heats up. Therefore, at Poyraz Endüstriyel, the approach is not only to suppress the fault but to verify that the drive remains stable under real operational scenarios.

The most common complaints about INVT drives in the field are: shaking/vibration at startup, speed fluctuations at low speed, jerking during floor approach, leveling errors upon stopping, overvoltage error during slowdown, faults during heavy traffic, intermittent resets/communication drops, and tripping the fuse when powered on. These symptoms do not always indicate an internal drive fault. Weak grounding, grid voltage drops/phase imbalance, motor cable insulation degradation, shielding faults, brake resistor/circuit issues, contactor/brake coil interference, and excessive panel temperature can cause the drive to protect itself, producing similar symptoms. Successful technical service clearly distinguishes between “drive failure” and “drive triggered by external factors.”

Helpful information to expedite the process includes: model (CHV 180, GD 20-UL, VFD-CHF100A, GD 300-L, GD 200-A), error code/screen message, the moment the fault occurs (startup–travel–slowdown), whether the cabin is loaded or empty, frequency of fault recurrence, panel temperature, and recent interventions. “Runs well unloaded, trips under load” indicates power board weakness/thermal issues or DC bus capacitor fatigue. “Error during deceleration” points to the braking side. “Breaker trips upon power-up” raises suspicion of short circuit in the power board.

What is an INVT Elevator Drive?

The INVT elevator drive is a VVVF inverter unit that controls the speed and torque of the elevator motor. It converts the AC power from the grid into DC bus voltage, then generates the appropriate frequency/voltage for the motor through switching elements. This enables smooth cabin start-up, stable travel speed, controlled deceleration during floor approach, and precise leveling at stops. The outcome is an improved operational character for both user comfort and mechanical system longevity.

The drive does not operate alone; it works integrally with the brake system, safety chain, contactors, and feedback elements (e.g., encoder). Therefore, a problem that appears as a drive fault may originate from the brake resistor circuit, power quality, or motor cable. For example, if the DC bus voltage rises during braking, the drive may register an overvoltage fault; the issue might stem from the drive itself or the brake resistor connection/value.

Internally, it generally consists of two main parts: the power board (rectifier, DC bus capacitors, IGBTs, braking circuits, pre-charge) and the control–power supply board (SMPS, processor, gate driver, current/voltage measurements, communication). The fault location determines symptom severity and recurrence characteristics.

How is the INVT Elevator Drive Repaired?

INVT drive repair begins with accurate information gathering from the field, progresses through layered diagnostics in the workshop, and concludes with verification under the motor. Simple checks such as “the device powers on” or “motor runs unloaded” are insufficient for elevator applications, as faults often trigger under load, braking, or heating conditions.

Initially, the error code, fault occurrence timing (startup/deceleration), cabin load status, and whether the fault worsens with heat are clarified. Then, visual inspection is done in the workshop: burn marks, swollen capacitors, darkened components, fan failure, dust blockage, cooling contact issues, and connector oxidation/loosening are examined.

On the power board, the rectifier, IGBTs, pre-charge circuit, DC bus capacitors, and braking circuit are measured. Aging of DC bus capacitors (increased ESR) can cause load fluctuations and protective faults. Weakness in the braking circuit may manifest as an overvoltage error during deceleration. On the control–power side, SMPS outputs are evaluated for ripple and thermal stability; weak power supply can cause intermittent resets, communication drops, and spontaneous stops.

The most critical step after repair is testing under the motor. Current draw, DC bus stability, thermal behavior, and repeated protections are monitored. Test duration is extended according to fault characteristics, as some drives fail after 30–60 minutes or specific load cycles. Delivery criteria require the drive to remain stable under conditions close to actual operation.

INVT Elevator Drive Faults and Symptoms

Faults in INVT drives often produce noticeable symptoms. However, it should be remembered that the same symptom can be caused by an internal drive fault or by external triggers. Correct interpretation of these symptoms reduces unnecessary parts replacement and risk of repeated failures.

Fuse blowing/circuit breaker tripping when powered on: A short circuit is highly probable on the power board (IGBT, rectifier, DC bus). Repeated attempts to power the drive may worsen the damage.

Drive powers up but motor does not run: Contactor control/brake management, drive circuitry (gate driver), output board, or motor/cable faults should be considered. Information that “command is received but no motion occurs” is critical for diagnosis.

Vibration/shaking at startup, speed fluctuations at low speed: Causes can include control loop instability, current measurement circuit deviation, parameter drift, or power supply fluctuations. Motor/encoder (if present) feedback issues create similar sensations.

Jerking during floor approach, leveling error at stop: Related to deceleration control, brake synchronization, and torque management, important for both comfort and safety perception.

Overvoltage error during deceleration: Connected to brake resistor/circuit, DC bus discharge, and grid voltage. Connection integrity and resistor health should be evaluated together.

Faults during heavy traffic: Increases likelihood of thermal issues. Fan function, air duct blockage, cooling contact, or power board leakage under heat may be factors.

Intermittent reset/communication drop: May be caused by SMPS instability, cold solder joints, socket contact loss, or interference (especially from brake coil/contactors).

Why Should You Prefer Poyraz Endüstriyel for INVT Elevator Drive Repairs?

The critical goal in INVT drive repair is to ensure the drive operates stably under field conditions and load cycles without recurring faults. The main reason to choose Poyraz Endüstriyel is that we do not stop at the level of “device powered on.” Our service approach focuses on identifying the root cause, performing necessary repairs, and delivering with motor-under-load verification.

In power board faults, we do not only replace faulty components; we check gate driver circuits, current/voltage measurement feedbacks, DC bus capacitors, pre-charge circuits, and cooling performance together. For power supply faults, it is not enough that the SMPS supplies output; ripple and thermal stability are measured. Issues like intermittent reset/communication drop are carefully examined for cold solder joints and socket contact loss because vibrations and thermal shifts in the field accentuate such faults.

We also provide practical recommendations on external factors triggering the drive (grounding, power quality, shielding, brake resistor, loose connections, panel temperature) to reduce the risk of recurring faults. Our delivery criterion is not “it works,” but “stable under motor load and reliable during heavy traffic.”

Supported Models

At Poyraz Endüstriyel, the INVT drive models we support include:

• CHV 180: Priority is given to stability under load, DC bus stability, thermal behavior, and startup–deceleration performance tests.
• GD 20-UL: Control–power supply stability and ripple/contact checks for intermittent reset/communication fault complaints are emphasized.
• VFD-CHF100A: Braking behavior, DC bus response, and thermal stability under heavy use are closely monitored.
• GD 300-L: Stopping accuracy, deceleration control, and long-term load testing are conducted for elevator applications.
• GD 200-A: Power board durability, power supply stability, and in-depth tests for “faults under load” reported in the field are performed.

Regardless of model, the most critical verification step is testing under the motor and thermal monitoring.

In What Cases Should an INVT Elevator Drive Be Repaired?

Situations indicating that an INVT drive requires repair include recurring faults/protections and deterioration in movement quality. Intervention is necessary if the elevator pauses trips, issues alarms, the drive locks up, or resets. Additionally, signs such as vibration at startup, speed fluctuation at low speeds, jerking during floor approach, and leveling errors on stop—even if the elevator operates—may indicate the drive is operating at its limits and could lead to more severe faults.

“Runs well unloaded, trips under load” suggests power board weakness, DC bus capacitor aging, or thermal issues. “Trips during heavy traffic” highlights cooling/fan and thermal stability concerns. “Error during deceleration” strongly indicates the braking circuit, brake resistor, and DC bus voltage rise.

Severe symptoms such as fuse blowing or circuit breaker tripping when powered on should not be delayed. Since a short circuit on the power board is highly likely, repeatedly powering the drive may worsen damage and increase costs. Early intervention improves repair chances.

Intermittent resets/communication drops also require repair. Initially infrequent, they worsen over time. Most often caused by SMPS ripple or socket/solder joint contact loss and are detected under thermal conditions in the workshop.

INVT Elevator Repair Process

The INVT drive repair process includes collecting field data, diagnostics and repair in the workshop, testing under the motor, and, if necessary, recommendations for field improvements. Skipping the verification step can result in the drive entering protection mode again under heavy use.

Initially, data such as model, error code, fault occurrence time, cabin load, and panel temperature are gathered. These data determine the test plan. If faults occur during deceleration, braking and DC bus response are monitored closely; if during startup, current measurement and output board are scrutinized more carefully.

Visual inspections and measurements are carried out in the workshop: power board components, DC bus capacitors, pre-charge, braking circuit; control board and SMPS power supplies. Intermittent faults prompt thorough investigation of cold solder joints and socket contact loss. After repair, motor-under-load testing observes current draw, heating, DC bus stability, and protection repeats. Some faults manifest over time, so test durations are extended according to fault characteristics.

How to Understand INVT Elevator Drive Faults?

The most practical way to understand an INVT drive fault is to evaluate the error code, the fault condition, and cabin behavior together. If there is an error code, record it and take a photo of the screen. Whether the fault occurs during startup or deceleration directly guides the diagnosis. Startup faults typically involve the output board/current measurement; deceleration faults point towards the braking and DC bus side.

Cabin movement symptoms are also important: vibration at startup, speed fluctuations at low speed, jerking during approach, and leveling errors indicate instability in drive control. However, motor, encoder (if any), brake adjustment, and mechanical load changes can produce similar effects. Therefore, hardware and external factors should be assessed before uncontrolled parameter changes.

If severe symptoms like fuse blowing or breaker tripping occur, avoid repeatedly powering the drive. If there is burnt smell, unusual heating, or smoke, power should be cut, and controlled diagnostics performed. For intermittent faults, recording fault frequency and conditions speeds up repair.

Why is the INVT Elevator Drive Important?

The INVT elevator drive is a fundamental component determining the quality and continuity of elevator movement. By managing motor speed and torque, it ensures smooth cabin start, stable travel speed, controlled deceleration, and precise stopping. Therefore, drive weaknesses directly affect user comfort and system reliability.

In terms of comfort, the drive controls parameters such as vibration, jerking, and stopping harshness, which directly impact users. A stable functioning drive reduces complaints and increases user confidence in the building. Leveling errors at stops are particularly critical for safe boarding and alighting.

Regarding mechanical lifespan, the drive reduces sudden current draws and harsh ramps, minimizing wear on ropes, sheaves, bearings, and connection elements. Correct brake management also prevents unnecessary strain on the brake system.

For continuity, drive faults can disable the elevator. Recurring failures increase both maintenance costs and operational downtime. Hence, healthy drive operation directly influences total operational expenses.

Precautions if the INVT Elevator Drive Breaks Down

When the INVT drive fails, the most critical aspect is safely controlling the situation without aggravating the fault. If fuse blowing or breaker tripping occurs at power-up, repeatedly trying to power the drive is not recommended due to high chance of short circuit in the power board. If there is burnt odor, abnormal heating, or smoke, power must be cut, and the device should not be operated uncontrolled.

Quick checks inside the panel include verifying fan operation, checking for air duct blockages, assessing if the drive is overheating, inspecting cable terminal tightness, connector oxidation/loosening, and signs of darkness on connections. Loose connections can heat up under load causing voltage drops and forcing the drive into protection mode.

External factors should also be reviewed: weak grounding, phase imbalance, grid voltage fluctuations, motor cable insulation leakage, shielding deficiencies, and brake resistor circuit problems. If these factors are not corrected, the repair may fail or faults may recur.

Noting the error code and the conditions under which the fault occurred (startup/deceleration, load status, temperature) accelerates diagnosis. Uncontrolled parameter changes can worsen the problem; therefore, controlled diagnostics are recommended instead of trial adjustments when a fault exists.

INVT Elevator Drive Repair Prices

INVT drive repair prices vary depending on the fault layer (supply, power board, control board), extent of damage, whether the fault is intermittent, and the duration of motor-under-load testing/monitoring. Therefore, providing a fixed price without seeing the device is often not accurate. At Poyraz Endüstriyel, we first classify the fault and then provide a transparent cost estimate.

Main factors affecting price:

• Supply (SMPS) and minor control faults: often can be resolved at lower cost; however, verification of ripple and thermal stability is mandatory.
• Power board faults (IGBT, rectifier, DC bus capacitors): may incur higher costs due to parts and labor.
• Chain damage: if one fault affects other circuits, costs increase.
• Intermittent faults: require extended testing time to detect and ensure non-recurrence in the field.
• Field triggers: if issues like grounding, brake resistor, or power quality are not resolved, the drive may fail again, impacting total cost.

Generally, the following information suffices for clearer pricing: model, error code, fault occurrence time (startup/deceleration), whether it worsens under load, panel temperature, and previous interventions. With these details, we classify the fault quickly and provide a precise repair cost.