Marvair, a division of Airxcel, released its CommStat 4 microprocessor controller, which will operate up to six Marvair air conditioners or environmental control units in a fully or partially redundant application in a telecommunication shelter or cabinet.

A large backlit LCD display shows the status of the system and provides a convenient user interface. The lead/lag function ensures equal wear on both air conditioners while allowing the lag function to assist upon demand. The lead/lag changeover is factory set at secen days, but is field programmable from half a day to seven days in half-day increments.

A single CommStat 4 will control two air conditioners or heat pumps, but has the capability to be daisy changed with up to two additional CommStat 4 units to control up to six air conditioners or heat pumps on a shelter. When two or three CommStat 4 units are daisy chained together, one of the units is the Master and controls all connected CommStat 4 units. Any settings to the master unit immediately take effect on the Slave unit(s). The interface is an RJ14 connector.