ECN Forum Forums General Topics of the Trade General Discussion Area What Square D I-Line breaker to use

You need to know:
Current Rating
Number of poles
Voltage of system
Available fault current

When in doubt, you should at least match the specifications of an existing breaker (hopefully they are correct for the application)

The current family offerings would be a QD @240V and a JD at 480V.
The previous families were Q2 @240V and KA @480V.