CHF100 Inverter Capacitor Board – Replacement DC Bus Filter Module for INVT CHF100/CHF100A VFDs

Overview 

The CHF100 Inverter Capacitor Board is an essential maintenance module for the INVT CHF100 and CHF100A series industrial VFDs. In any VFD, the rectifier section converts AC to DC, but this DC signal is often “pulsating.” The capacitor board acts as a high-capacity filter and energy buffer, smoothing this ripple into a stable DC bus voltage. A faulty board often leads to “Under-Voltage” or “Over-Voltage” errors, or unstable motor speed/torque.

Key Features 

• Voltage Stabilization: Effectively filters ripple current from the rectifier, ensuring the inverter receives clean, stable DC power.

• Energy Buffering: Provides the necessary instantaneous energy storage required during motor acceleration and high-demand torque response.

• Long-Life Electrolytics: Uses high-temperature, low-ESR capacitors designed for the high-frequency switching environments of industrial drives.

• Protection Mechanisms: Integrates balancing resistors and discharge circuitry to protect the capacitor bank and internal IGBTs from voltage surges.

• Direct Replacement: Designed specifically for the physical footprint and pinout of the CHF100 series for hassle-free installation.

Technical Specifications 

When to replace your Capacitor Board? 

• VFD Error Codes: Frequent “DC Bus Under-Voltage” or “Over-Voltage” faults that don’t go away.

• Visible Damage: Capacitors showing signs of bulging, leaking, or burnt PCB traces near the discharge resistors.

• Audible Noise: A high-pitched “whine” coming from the VFD during operation, often indicating failing or drying-out capacitors.

• Motor Instability: Inconsistent motor RPM or “hunting” (speed fluctuation) under load.