INVT GD300L Elvator Drive Used in Bharat Bijlee (BBL) Gearless Controller for Elevator Modernization in India

Abstract: This case study highlights how the GD300L elevator drive, developed by INVT, was successfully integrated into a Bharat Bijlee (BBL) panel to replace the proprietary system. The project enhanced control performance, reduced operational and maintenance costs, and offered customers a cost-effective alternative to break the service monopoly of the original brand.

Keywords: INVT GD300L, PG card & BBL Machine.

Customer Background

The customer operates a residential building in India equipped with locally manufactured elevators control system. The existing elevator panel used a with permanent magnet (PM) motors.

This configuration, while reliable, posed several challenges:

• Proprietary design: The closed architecture required OEM parts only.

• High costs: Spare parts and service from the OEM were expensive.

• Limited flexibility: Integration with other drive systems was restricted.

Because the original drives were installed in the field, replacing them with new OEM units would have been a costly solution. The customer sought a more economical, reliable, and easily serviceable alternative.

Challenges

1. Replacing the existing KEB proprietary system without altering the entire control infrastructure.

2. Ensuring compatibility with synchronous (gearless) motors.

3. Maintaining elevator safety, ride comfort, and performance.

4. Reducing long-term maintenance and spare part costs.

5. Achieving smooth commissioning with minimal downtime.

Solutions

The engineering team proposed replacing the KEB drive with the INVT GD300L series elevator drive. This drive was selected for its:

• Compatibility with both geared and gearless motors.

• Support for open-loop and closed-loop control (with encoder).

• Static motor auto-tuning function, eliminating the need for de-roping.

• Multiple encoder support (incremental, sine-cosine, absolute, and UVM).

• High reliability and ease of maintenance.

This solution allowed seamless integration into the existing BBL panel without the need to overhaul the entire system.

Implementation Details

Lift specifications

• Speed: 0.300 m/s

• Capacity: 3 persons

• Floors: 3

• Motor: 0.75 kW synchronous motor

Hardware configuration

• Control panel: BBL panel with GD300L drive

• Encoder: incremental type ABZ Hohner

• Brake resistor

Debugging steps

• Manual brake release

• Encoder pulse verification

• Parameter tuning and drive synchronization

Results

• Performance: Smooth and stable operation with precise leveling and acceleration.

• Cost efficiency: Significant savings compared to OEM drive replacement.

• Maintenance: Simplified debugging reduced downtime and service dependency.

• Compatibility: Full functionality achieved with existing BBL panel and motor.

• Reliability: Drive performance remained stable over extended operation.

Customer Feedback

The customer reported high satisfaction with the GD300L integration. Key feedback points included:

• Noticeably smoother operation compared to the old KEB drive.

• Reduced service cost and easier availability of spare parts.

• Appreciation for the remote diagnostic feature, which improved service response time.

• Positive evaluation of overall reliability and ease of maintenance.

Conclusions

This project confirms that GD300L can effectively replace KEB drives in Bharat Bijlee elevator systems. The solution provided:

• Cost-effective maintenance and operation

• Full compatibility with existing panel and motor systems

• High performance and reliability

• Easier service and diagnostic capabilities

The successful deployment demonstrates INVT’s ability to offer competitive alternatives to proprietary OEM systems in the elevator market.