Solid State main breakers for panelboards start at 400 amp.  Branch breakers are offered at lower amperage"s. 

Step-by-step guide

1. Add the branch breaker as normal process, enter Qty, Poles, Trip Amps, click on Add button, i.e., enter Qty 1, 3 poles, 250 trip amp, click on Add,
2. Once the breaker is added, click on PROP button to open breaker properties sheet,
   
   
    
3. On the properties page on the side of screen, Trip Unit Type option is set to “Thermal Magnetic” as default, reset it, then change it to Solid State,
4. Once it is changed to Solid State,  it is required to select breaker Sensor setting and Trip setting. Breaker Type @ IR will then change to a solid state breaker type accordingly.  
   For example, select Sensor as 250, and Trip as 150, the breaker is set to NF type solid state breaker.
   
   
    

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