Does the NEC® allow circuits from the panels to enter the same pull box?

The National Electrical Code (NEC®) does permit circuits from different panels to enter the same pull box, provided they comply with certain conditions laid out in the code. This is primarily to ensure the safety and functionality of the electrical installation.

When circuits from multiple sources are routed to a single pull box, it's essential to ensure that the circuits are compatible, meaning they should not introduce any overloads or conflicts in terms of circuit ratings. The pull box must also be adequately sized to accommodate all the wires without overcrowding, maintaining the necessary clearances and allowing for proper thermal management.

Additionally, while label requirements and specific installation practices may need to be adhered to, the fundamental allowance for multiple circuit entries exists within NEC guidelines. Proper installation reduces confusion during maintenance or troubleshooting and helps ensure the integrity of system operations.