Defines how much energy is saved when the Load is shed. This attribute specifies the information that DLLR needs to control the load. This includes a Shed to value, which is the value to which DLLR commands the output when the load is shed. Also required is at least one Shed from/Energy Savings pair, which indicates the amount of energy that would be saved when the output is commanded from the Shed From value to the Shed to value. For binary outputs, only one Shed From/Energy Savings pair is needed, since it can have only two possible states (Shed To and Shed From). For multistate and analog output objects, there can be multiple Shed From/Energy Savings pairs, since they can have many possible values, and differing amounts of energy might be saved depending on the value the output had when the shed occurred. The option for adding multiple load ratings helps improve the accuracy of the shed process.
Consider an example of a fan that should be shed to 60%. The first Shed from entry is 100%, because the most energy would be saved when shedding from this state. The second Shed from entry is 90%, the third entry is 80%, and so on.
Also, consider an example of a three-speed fan that can have the following states: High, Medium, Low, and Off. The operator decides to set the fan to Low when the Load is shed. In this case, the first Shed from entry is High because the most energy would be saved when shedding from this state. The second Shed from entry is Medium. A Shed from entry for Off is not required because no energy is saved by shedding from Off to Low. The entries might look like this:
|
Shed from |
Shed to |
Energy savings |
|---|---|---|
|
High |
Low |
5.0 kW |
|
Medium |
Low |
3.2 kW |