With the AK-PC 781 Multifunctional Pack Controller, it is easy to set up energy-efficient capacity control of refrigeration compressors and condensers with modular hardware and flexible software that extends as system requirements grow or change, the company said. It enables configuration of inputs and outputs for sensors, switches, and relays with a modular controller that can change as needs change, plus provides oil management, heat recovery, and CO2 gas-pressure control. The controller ensures precise and stable suction and condensing pressure regulation for a variety of applications and refrigerants, the company said. Modules snap onto a common platform to accommodate digital and analog inputs and outputs for compressors, condensers, gas coolers, fans, expansion valves, sensors, switches, and alarms. Capacity control is available for up to eight compressors, with three unloaders for each compressor. Functions include speed control of one or two compressors, handling up to six safety inputs per compressor. Optional capacity limitation is available to minimize peak energy consumption, capacity control for up to eight fans, and coordinating cascade controllers for medium- and low-temperature operation. Controller programming can be accomplished with a PC using AK-Service Tool software. The controller networks with other Adap-Kool® refrigeration control systems.