2. Describe the “5 R’s” of switching.
- Take maximum demand and/or observed ammeter readings to determine that equipment ratings and relay settings will not be exceeded. Check the current readings (or use Max Demand) at the substation(s) on all three phases of both circuits for unusual
- readings if switching or paralleling is within substation or on feeder cable.
- Ratings and settings are found on station one line diagrams and protection information
- sheets. Additional voltage regular ratings can be found in OO 2T-04.
Automatic reclosing must be turned off unless specified differently in other operating orders or with approval of the SCM
Enable ground trip blocking on electronic reclosers when performing single phase switching (OO 2T-24)
- Series reactors significantly affect load sharing, if their impedances differ. When switching involves breaking distribution feeder loops or parallels, the reactor impedance in each branch must be considered to determine the loop impedance and the current shared in each branch. Compare the current to the maximum current
- interruption capability of the switch to be opened.
When feeders fed from the same source are tied together in the substation, voltage regulators are placed in NCO (neutral position and the control circuits switched off)
When feeders fed from a different source are tied together in the substation, the regulators to be paralleled should be set on different percentage taps to offset transmission differences.
When feeders fed from the same source are tied together in the field, the voltage regulators are to be placed in manual control mode with taps on the neutral position and the control circuits switched off (NCO).
When feeders from different sources are tied together in the field, leave the voltage regulators in automatic control mode