Issues

A corporate data center in New York had two 50-ton Maverick II units installed with the second unit providing critical redundancy. As the number of servers installed in the space grew, the cooling load in the data center grew as well. The second Maverick II unit became a primary unit and a third unit was installed to provide redundancy and avoid expensive downtime in case of a loss of cooling.

The data center facility did not have a building automation system and therefore had no way to automatically bring up the backup unit if one of the two primary rooftop units failed. The Sales and Service branches of the Daikin Applied New York office worked together and identified the MicroTech System Manager as a solution to the customer's requirement for rooftop sequencing, remote access and alarm notification.

Solution

A MicroTech System Manager was set up with three ancillary control loops. One loop monitors the status of the two primary units. If the System Manager recognizes an alarm status in either of those two primary units, it initiates the startup of the third rooftop unit to meet the cooling load requirement. Another loop monitors the discharge air temperature of the two primary units and the discharge air set point. If the discharge air temperature exceeds the set point by 10 degrees for 30 minutes, then the third rooftop unit is started and the rooftop producing the insufficient cooling is shut down.