Issue:
Fully rated and Series rated panelboard difference
Product Line:
Panelboards
Environment:
UL, NEMA
Cause:
An understanding of the difference between series and fully rated equipment is essential to any application when both are under consideration.
Resolution:
The short circuit current rating (SCCR) of a fully-rated system is equal to the lowest ampere interrupting rating (AIR) of any overcurrent protective device (main or branch) installed. Also, with a fully-rated system, individual devices can open at specified fault levels without affecting the remainder of system. Series-rated panelboards accomplish the interruption of high level overcurrents by using a combination of main and branch devices. Consequently, for a series-rated panelboard a high level overcurrent on a branch circuit can result in the main device opening and interrupting power to all circuits served from the panelboard. The chief attraction of a series-rated panelboard is a lower initial cost of equipment.