Variable-speed scroll compressor
Apexx VSH series compressors are said to be the first R-410A variable speed scroll compressors for commercial air-conditioning and heat pumps. Capacity of the VSH series varies continuously to match the system load, with an operation range from 30 to 90 Hz. The company offers three VSH packages that cover a 90-Hz design capacity range from 11 to 23 TR (R-410A). Delivered capacity is from 3.5 to 23 TR, depending on the load. The drive in each VSH package is also designed specifically to match its compressor. Compared to conventional systems, energy savings with a VSH compressor are reported to exceed 20%. The Apexx VSH compressor is designed to maintain high isentropic efficiency at part load, and has the inherent benefit of continuously matching the load. Continuous operation means less cycling and system stress, higher reliability, and longer life. Customized drive software protects the compressor and provides multiple control options supported by I/O capability for communication, control, and monitoring. Smaller than a fixed-speed compressor of similar capacity, the VSH compressor lets designers create more compact designs. The series includes a user-definable, closed-loop PID capacity controller; load monitoring; and a pack controller for hybrid units that have VSH and fixed-speed compressors. An optional graphic display and keypad, with onboard memory, can be used for parameter changes and commissioning.
Danfoss , Baltimore,