Chiller/Boiler Step Strategy - Metasys - LIT-12011288 - Software Application - Metasys Building Automation System - 6

DLLR Technical Bulletin

Product
Building Automation Systems > Building Automation Systems > Metasys Building Automation System
Document type
Technical Bulletin
Document number
LIT-12011288
Version
6
Revision date
2013-10-15

Some energy saving applications can be difficult to implement given that you can add only one Load extension to an object and you can shed to only one value (Figure 1).

For example, if you intend to step the load capacity of a chiller or boiler to 90% and then step down to 80%, 70%, and so on, you cannot do so using a single object with a single load and single shed value. One way to work around this issue is to create 5 Binary Value objects. Each object represents a step 10% decrease in capacity of the chiller/boiler. For logic associated with this example, see Figure 2.

Figure 1. Example of Single Load Extension with Single Shed Value

Figure 2. Example of Boiler Capacity Limit Logic