Any scenario where a control power transformer (CPT) is installed requires the additional selection of fuses based on the short-circuit protection requirements of the CPT itself, as well as overload protection requirements based on the load that the CPT is connected to. To select the proper fuses for your control power transformer, apply the following steps to the primary and secondary fuse sizing tables below:
- Determine if your application is a power circuit or a motor circuit, and refer to the corresponding primary fuse sizing table
- Identify your primary voltage on the left side of the table and your transformer VA rating at the top of the table
- Use the specified primary voltage and transformer VA rating to determine the required fuse size
- Repeat Steps 2 and to find the required fuse size for your secondary voltage
