What is the 1 phase 3 phase rating on the circuit breaker label?
Defining ratings on faceplate label
1ph-3ph symbol is undefined
The single phase - three phase rating is specifically for the Grounded B Phase (Corner-Grounded Delta) system, otherwise use the standard ratings on the label.
See the below example for a 240Vac Corner Grounded System, and ratings for 2p and 3p QD breakers