11.6 Optical budget calculation for PMU - PDCcommunication GUID-F5DEACB1-4B83-4C68-B59A-694CAC78AF3D v3Most of the times, the PMU IEDs are located in the substations. A local PDC mightbe located in the substation. For communications within the substation or betweenthe IED and the WAN/LAN access point, it is important to know what is the opticalbudget available. The graph in Figure 38 shows the dynamic range available for aPMU – PDC configuration using typical OEMs.141210864200 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.062.5/125 μm50/125 μmOPB – OPTICAL POWER BUDGET - dBFIBER OPTIC CABLE LENGTH - kmIEC11000409_1_en.vsdIEC11000409 V1 EN-USFigure 38: Optical power budget for fiber optic cable lengthsAs shown in the graph, if one uses a 62.5/125 μm fiber, the value under the62.5/125 μm curve represents the remaining optical budget at any link length,which is available for overcoming non-fiber cable related losses.Losses in the connectors and splices are typically 0.3dB/connection. The user mustreserve 3dB spare for the uncertainty of the measurements.Section 11 1MRK 502 073-UEN AEstablishing connection and verifying the IEEE C37.118/1344 communication114 Generator protection REG670 2.2 IEC and Injection equipment REX060, REX061, REX062Commissioning manual
