Application Note : Controlling an RTU with Siemens POL 220 Economizer with a Hyperstat

Problem:

Due to cost, there are times when a CCU + OAO Kit is not desired for RTU Control. If the RTU in question has a Siemens POL 220 Economizer Control Board, we can control the economizer to meet DCV Control, but does not allow true economizing control.

Solution:

Using a Hyperstat CPU Kit, the user can follow the drawings below to configure and wire the correct terminations to control the unit for a much lower cost.