Description of Operation
In general, it is best to start with a relatively large proportional band setting (the factory default setting is best) and adjust to smaller values.
If you want the system to respond strongly to small changes in the space, adjust the proportional band to a higher setting.
If you want the system to react weakly to small changes in the space, adjust the proportional band to a higher setting.
Integral Time
The integral time, or integral action, causes the controlled output to change in proportion to time difference between the sensor value and set point. The difference over time between the actual value and set point forms an “area under the curve” (see Figure 22). The integral action works to reduce this “area under the curve” and to eliminate any natural system offset.
Figure 22: Integral time
Area Under The Curve | Too Small |
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The smaller the integral time, the faster the output ramps up or down with small changes in the space. The smaller the integral time, the quicker the system reacts to small changes in the space. If the Integral Time is set too small, long oscillations occur (see Figure 22).
In general, it is best to start with a relatively large integral time setting (the factory default setting is best) and adjust to smaller values. If you want the system respond strongly to small changes in the space, lower the integral time. If you want the system to react weakly to small changes in the space, adjust the integral time to a higher setting.
Indoor Air Fan Operation
The UVC supports a
Auto Mode
The UVC is provided with a user selectable auto fan mode feature. When in auto fan mode, the UVC uses the space temperature PI loop to automatically adjust the fan speed as needed to maintain space temperature. This ensures that the UVC maintains the lowest and quietest fan speeds whenever possible. When in auto fan mode, a maximum of six fan speed changes per hour is allowed (by default). This prevents frequent automatic fan speed changes from disturbing room occupants.
Occupied, Standby, and Bypass Operation
During occupied standby and bypass modes, the IA fan, by default, remains On.
McQuay OM 751 | 31 |
