Before you begin installation, ensure there is no voltage hazard. The new panelboards are not energized yet, but what about existing panelboards you are joining to? Use a meter to verify the existing panelboards are dead. Check all feeders and control power circuits. If you measure a voltage, find the source. If there are power factor correction capacitors involved, then isolate them.
Check for bonding deficiencies. If they exist, then you could receive a nasty shock halfway into the job. Ensure any metallic enclosures are bonded per Part V of Art. 250.
Before energizing:
- Check the bonding connections again.
- Complete the recommended resistance tests because these help identify wiring errors or misplaced tools that could produce a major arc blast risk.
- Perform a tool count. If a tool is missing, it probably did not run away on its own. Check methodically. One technique is to retrace backward through each step of what you just did. Rather than scan with your eyes, touch with your hands.
- Close all doors and secure all covers.
