Index

# RELAYS 101

### Primary Impedance/Secondary Impedance Converter

Enter any three of the four values below and click calculate to find the fourth value. To calculate Primary Ohms to Secondary Ohms on your own: First multiply the primary ohms by the current transformer ratio. Then, divide the product by the potential transformer ratio. (Ohms Secondary) = (Ohms Primary) x CTR / PTR To convert secondary ohms to primary ohms first multiply the secondary ohms by the potential transformer ratio. Then, divide the product by the current transformer ratio. (Ohms Primary) = (Ohms Secondary) x PTR / CTR Visit the Lecture Notes page to see the mathematical derivation of the conversion calculation.

PT Ratio (to 1):

CT Ratio (to 1):

Primary Impedance:

Secondary Impedance:

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