EXCEL CARE CONTROL ICONS ALPHABETIC REFERENCE97 74-5577–33 (US)EN2B-0184 GE51 R0518 (Europe)Switching Off XFM 36-1 Loads XFM 35 switches off Priority Group 1 XFM 36-1 loads first. It then switches offPriority Group 2 loads and then Group 3 loads.XFM 35 sets the Priority Group 1 Po1 output to a negative switch-off power value aslong as the value of user address ID___Off_Prio_1 is 1 (True). After all loads inGroup 1 are off, software sends a zero value (False) to ID___Off_Prio_1.XFM 35 then sets the Priority Group 2 Po2 output to a negative switch-off powervalue as long as the value of user address ID___Off_Prio_2 is 1 (True). After allloads in Group 2 are off, software sends a zero value to ID___Off_Prio_2.XFM 35 then sets the Priority Group 3 Po3 output to a negative switch-off powervalue as long as the value of user address ID___Off_Prio_3 is 1 (True). After allloads in Group 3 are off, XFM 35 sends a zero value to user addressID___Off_Prio_3.At this point, there are no more loads that can be switched off. All three useraddresses, ID___Off_Prio_1, ID___Off_Prio_2, and ID___Off_Prio_3, are zero.XFM 35 cannot distribute the next calculated negative power value to any load (asall loads are shed [off]). XFM 35 initiates an alarm by setting user addressID___Man_load _shed to zero. This alarm means that manual load shedding isrequired.XFM 35 AlgorithmsXFM 35 provides three measurement and calculation algorithms (Sliding Window,Ideal Curve, and Extrapolation) that you can select as required. To select analgorithm, set Parameter P9 to the values 1 (Sliding Window), 2 (Ideal Curve), or 3(Extrapolation).Each algorithm measures the current power consumption, compares it to a powerlimit (Parameter P13 or P14), and calculates a power value for the XFM 36-1/S/Rsingle-stage load control programs. A positive power value switches ON a load. Anegative value switches OFF one or several loads. The maximum switch-onparameter (P5) limits the power value from an algorithm.Each algorithm samples the gradient of energy used and calculates the power to beswitched. Sampling occurs 10 times per measurement interval or window time frame(Parameter P10).Sliding Window Algorithm The Sliding Window algorithm provides a simple, but useful, control of the powerpeak without the need for synchronization pulses. The Sliding Window algorithm isused primarily in the US.Using a sliding time axis, the algorithm stores the increasing, measured power value(at the first XFM 35 input [Zi]) every tenth of the window time frame (1/10 ofParameter P10). The following diagram illustrates this technique.
