Technical Instructions
Polygyr-Compact Discharge Air Temperature Controller
Document Number CM1N3407E-P25
Rev. 1, February, 2000
Page 2
Siemens Building Technologies, Inc.
Function
The RCM61.22 provides PI control. The proportional band can be adjusted. The
controller compares the actual value with the set point and generates a proportional
control signal when a deviation occurs. The control signal is continuous and has a range
of 0 - 10 Vdc. When the control signal changes from 0 – 10 Vdc, the correcting variable
changes from 0 - 100%, i.e., there is a proportional relationship between the correcting
variable and the control signal. The adjusted Xp (proportional band) refers to heating
(Y1). The P band for cooling (Y2)is half as wide, making it possible to obtain the same
control quality for both heating and cooling, although the control conditions are different
(nearly the same plant gain with different correcting spans).
Each control output generates a control signal of 0 – 10 Vdc. The outputs are switched
in sequence and their mode of operation is opposed making it possible to provide
sequence control of two actuators with different modes of operation.
Y
Q
Q
Y
Load
Signal voltage
Heating
Cooling
0
10V
SASC0016R1
0
Figure 1.
Compensation
The reference value is fed to the controller, which shifts the set point. There are two
possibilities:
•
Universal compensation over the whole setting range or over any part of the setting
range with the help of the RZF61.100 universal shift controller, or from a building
automation system.
•
Set point adjustment within ± 10% of the setting range; this is generally made from
a building automation system.
For more information on compensation, see
Application
.
Design Features
The RCM61.22 is a small, electronic controller that combines electronics, setting scale
and sensing element into one unit.
The casing is plastic with a removable cover, fully active flexible sensing element, and
removable mounting flange with adjustable positions.
All setting devices and connecting terminals are contained in the housing and
accessible only when the cover is removed.