Product Description:

The 167F3934 variable-speed drive is part of the Danfoss VLT FC 102 HVAC Drives series. In HVAC automation, it adjusts the frequency supplied to induction motors so fans, pumps, and compressors can follow building demand more closely. This operating method helps ventilation and fluid-moving equipment run at the required speed instead of remaining at full output during lighter loads. Because motor speed can be matched to system demand, the drive supports smoother control of airflow and water circulation in variable-load HVAC applications.

The drive operates from a three-phase supply of 380–480 VAC and connects through three-phase power terminals. Its IP20 chassis enclosure provides basic finger protection for cabinet installation, and the built-in RFI filter helps limit conducted emissions. It uses normal cabinet mounting on frames A, B, and C. The brake-safe stop selection omits a brake chopper, so regenerative energy must be handled externally. The unit has no mains option, which means mains isolation must be provided in the panel, and the PCB is uncoated for use in clean, temperature-controlled electrical rooms.

Network communication is provided by the EtherNet/IP MCA 121 A-option card, while the MCB-109 I/O and RTC backup B-option adds extra terminals and a battery-backed real-time clock for time-stamped alarms. Relay interfacing is handled by the MCB-113 extended relay card in the C1 slot, and local setup is performed with the graphical local control panel on the front door. The added relay and clock functions are useful when external status signaling and event logging are needed at the drive level. Cable routing uses standard cable entries under Adaptation A, while Adaptation B indicates no mechanical changes. The C option slot carries no software option, and the drive has no C0 or D option hardware, so the enclosure arrangement remains unchanged.