Frequently Asked Questions

Why does the 11kW model jump to 17kVA capacity from 11kVA on smaller models?

The Drive-11KW-4 features 17kVA power capacity—a 55% increase over the 7.5kW model—to support the substantially higher power demands of high-speed and high-rise operation. At 2.0-2.5m/s speeds, elevators require significant energy for rapid acceleration and to overcome windage/friction in tall hoistways. The 27A output current (50% higher than 18A) and 29A input current reflect this high-performance capability. The 17kVA rating ensures stable operation even with voltage fluctuations common in high-rise building electrical systems.

Is the 11kW inverter suitable for 3.0m/s ultra-high-speed elevators?

The 11kW with 27A output supports elevators up to 2.5m/s for typical 1000-1600kg cabins. For 3.0m/s ultra-high-speed applications or cabins exceeding 2000kg, the 15kW (33A) or 18kW (40A) models provide necessary power margins. The 11kW excels in the 2.0-2.5m/s range where it balances performance and efficiency. Our engineers can calculate exact power requirements based on your specific speed, load, and building height specifications.

How does the dual CPU handle emergency rescue in super high-rise buildings?

In super high-rise applications (40+ floors), the dual CPU architecture becomes critical for safety. One CPU maintains precise motor control during UPS-powered rescue descent, while the other manages door zone detection and safety circuit monitoring across extreme heights. The system calculates floor position from encoder feedback even during power loss, ensuring the cabin reaches the nearest floor—critical when passengers are stranded hundreds of meters up. The 11kW’s 17kVA capacity ensures sufficient torque for controlled descent with full passenger load.

What makes this 11kW model different from general-purpose 11kW VFDs?

Unlike standard industrial VFDs, the Drive-11KW-4 is specifically elevator-optimized with S-curve acceleration profiles that eliminate passenger discomfort during high-speed operation, dedicated anti-rollback logic for gearless PMSM motors, and multiple UPS rescue modes required by elevator safety codes. The removable PG cards accommodate high-resolution encoders (2048-4096 PPR) typical in high-precision high-rise gearless motors. General-purpose VFDs lack these elevator-specific safety functions and smooth ride algorithms essential for passenger transport at height.

Can this drive handle the regenerative energy from a fully loaded cabin descending 50 floors?

Yes. The built-in 11kW brake unit is rated for the regenerative energy from full-capacity descent, but super high-rise applications with frequent heavy downward traffic may require additional braking assessment. The 17kVA power capacity provides substantial headroom, and the drive supports external braking resistors if duty cycle calculations warrant. For buildings with predominant downward rush-hour traffic (e.g., office towers at closing time), we recommend regenerative drive options or braking resistor banks. Contact our engineers with your traffic analysis for precise braking configuration.