Answer :
When a buck-boost transformer has a current less than nine amperes, an overcurrent protection device is allowed to be rated at not more than 125% of the transformer's primary current.
To calculate the rating of the overcurrent protection device:
1. Determine the primary current of the transformer (let's assume it's less than 9 amperes).
2. Multiply the primary current by 125% (or 1.25) to find the maximum allowed rating for the overcurrent protection device.
For example, if the primary current is 8 amperes, the maximum allowed rating for the overcurrent protection device would be 8 x 1.25 = 10 amperes.
To know more about overcurrent protection device:
https://brainly.com/question/28256039
#SPJ11