A. Provide the quantity of across-the-line motor starters and/or transformer feeders, as indicated on the Drawings. B. The structure shall be divided isolated compartments 1. Main power bus and ground bus compartment 2. Power cell compartment 3. Low Voltage compartment C. Power Cell Compartment 1. Main Isolating Switch a. The main power cell shall have an externally-operated, 3-pole, gang operated, fixed mounted non-load-break isolating switch. b. The isolating switch shall isolate the power bus compartment from the power cell by means of a positively driven shutter mechanism to prevent accidental contact with line terminals in the power bus compartment. c. The main power cell door shall have a viewing window through which the operator can verify the isolating switch position. d. The isolating switch shall only have the ability to interrupt the no-load (magnetizing) current of the control power transformer(s) (CPT) and/or potential transformers (PT) supplied inside the controller power cell. e. In the open position, the isolating switch and contactor shall provide a means of grounding appropriate medium voltage power cell components, bleeding off hazardous stored energy, thus providing safe operation and maintenance...
