Square D QO1520 15/20A Tandem Miniature Circuit Breaker

The QO1520 is a non-CTL (Circuit Total Limiting) breaker designed for older QO load centers that predate CTL requirements. It lacks the mounting rejection clip found on the QOT1520, which is a CTL breaker designed for modern panels with notched bus bars.

No. Square D QO and Homeline breakers are not interchangeable. The QO1520 requires a QO load center, whereas Homeline panels use a completely different bus bar and mounting design.

This tandem breaker provides one 15-amp circuit and one 20-amp circuit within a single pole space. Each circuit operates independently with its own toggle switch, but they both draw power from the same phase of the panel bus bar.

No. Because both the 15-amp and 20-amp circuits connect to the same bus bar stab, they are on the same phase. Multi-wire branch circuits require two separate phases to prevent overloading the shared neutral wire.

No. This is a standard thermal-magnetic breaker. It does not provide GFCI (Ground Fault Circuit Interrupter) or AFCI (Arc Fault Circuit Interrupter) protection.

Non-Class CTL indicates the breaker does not have a physical rejection feature. It is intended strictly as a replacement part for older panels that were manufactured without physical restrictions on the total number of tandem breakers allowed.