Meaning of the terminology "referring to primary" or "referring to secondary" in the context of transformers equivalent circuits
&quot;Referring&quot; is a term used in simplifying the equivalent circuit. It is sometimes useful to view the transformer load and secondary impedance as if the ideal transformer is not part of the circuit and the load and impedance of the secondary winding are multiplied by the transformer ratio and shown as part of the primary circuit. There are also times when it is convenient to show the primary impedance as part of the secondary circuit. That process is called &quot;referring.&quot; In a way, it does mean looking into the circuit from the primary side or the secondary side, but part of that is adjusting the impedance values so that you have an &quot;accurate view.&quot;