The Reactance Multiplying Factor (RMF) is read from table 4 (?
The total short circuit capacity available is This current is the same magnitude with an X/R ratio equal to 4.899 (HV Bus 1), 10 (HV Bus 2) or 999 (HV Bus 3). We must now adjust for the X/R ratio. The test X/R ratio for this type of equipment is 15, see Table 1. Therefore, we do not adjust for breakers 52-1 or 52-2. However we must adjust for breaker 52-3. From Table 6 for an X/R ratio of 999 we can read for a 3-cycle breaker a MF of 1.35. Note, the table only goes up to an X/R of 130. This matches the results of the Equipment Evaluation and the SC.rpt file. Example 9 A co-worker has brought you the following single line diagram. The client he is working for is coming into the office for a review meeting. He would like you to quickly pop his proposed system into PTW and tell him what short circuit ratings are required for the SWBD and 2 panels. – There is no charge number for this assignment. – Make assumptions for missing data! – His last request is that since there are so many unknow
