The ratio of current transformers is typically expressed as what value?

The ratio of current transformers is typically expressed in a way that indicates the relationship between the primary current flowing through the transformer and the secondary current that is produced. A common and standard ratio for current transformers is 5:1. This means that for every 5 ampere of current in the primary winding, the transformer will produce 1 ampere in the secondary winding.

This ratio allows for accurate measurement and protection in electrical systems. Using a ratio like 5:1 helps in various applications including metering and protective relaying, where a lower current in the secondary circuit is more manageable and safer for instruments. Hence, acknowledging this standard ratio helps in understanding how to apply and integrate current transformers effectively in electrical systems.

Other values such as 1, 10, or 2 could represent different configurations or applications, but they are not typical standard values for current transformers. The prevalent usage of the 5:1 ratio reflects both a common practice and is often seen in specifications for devices in the industry.