A major East Coast university was relying on aging 18-pulse VFDs that were becoming increasingly unreliable and difficult to support. As failures began to impact operations, the university knew it needed a long-term plan to modernize its HVAC drive systems.

What started as a challenge in equipment reliability quickly became an opportunity to rethink standardization—and set the stage for a smarter, more sustainable solution.

CHALLENGE

The university’s HVAC system relied on aging 18-pulse VFDs, leading to several challenges:

• High Harmonic Distortion: Legacy drives failed to meet IEEE-519 standards, negatively affecting power quality.
• Complex System Design: Bulky 18-pulse transformers required significant space and complicated wiring.
• Rising Maintenance Costs: Frequent failures and declining efficiency led to increased operational expenses.

SOLUTION

To address drive failures and modernize its HVAC infrastructure, the university standardized on Yaskawa drives—known for their longevity and strong technical support. Aging non-Yaskawa units were replaced with Z1000U Matrix VFDs, which outperformed the previous 18-pulse models in harmonic reduction and eliminated the need for bulky transformers and external diode bridges.

This simplified system design and reduced installation time. With direct AC-to-AC conversion, the Z1000U improved energy efficiency, enhanced power quality, and freed up valuable mechanical space—establishing a new standard for campus-wide upgrades.

RESULTS

The university benefited in several ways, including:

• Reduced Harmonic Distortion:
  • The new system now complies with IEEE-519 standards.
• Simplified System Design:
  • The removal of bulky transformers and extra wiring has streamlined the HVAC system.
• Lower Maintenance Costs:
  • The university has experienced improved reliability and fewer component failures.

KEY Z1000U FEATURES

• Adheres to the 5% input Total Harmonic Distortion (iTHD) standard as per IEEE 519 guidelines for harmonic mitigation at the input stage
• Adjustable torque limit and overtorque settings for optimized acceleration and machine protection
• Equipped with a Safe Torque Off (STO) safety feature, meeting the requirements of IEC62061 (SIL3) and EN/ISO 13849-1 (PLe)
• The Z1000U Matrix VFD is designed to be reliable, as it does not rely on bus capacitors that degrade over time, contributing to a long product lifespan
• Built-in fusing
• Access to Yaskawa’s award-winning 24-hour technical support is free of charge. We are committed to providing our customers the highest level of service and support, ensuring they can rely on us for any assistance they need with our products

Looking to improve energy efficiency and power quality?
Contact Yaskawa today