Current transformers (CTs) and potential transformers (PTs) are crucial components for current and voltage monitoring. They measure the current and voltage of various power systems, ensuring these systems maintain precise and safe outputs, and they’re often used together to ensure that all instrument transformers are functioning properly.
However, while they are both instrument transformers, and play similar roles in safeguarding electrical systems from overcurrent and overvoltage, CTs and PTs have key differences in their function and application.
Current Transformer: Simplifying AC Measurement
CTs measure alternating current, and are crucial for stepping down a high current to a safer level that’s more manageable for the system. They can be configured to monitor overcurrent, undercurrent, peak current, and average current conditions, but regardless of configuration, CTs are important for maintaining the safety of the overall electrical system.
CTs are incredibly accurate no matter the actual AC load, so they’re often found in substations, power plants, and industrial settings, places where that accuracy is incredibly important. They most often feature a toroidal design to maximize their ability to handle those high currents.
Potential Transformer: Consistent Voltage Monitoring
PTs differ from CTs mainly in their function–instead of measuring and stepping down current like a current transformer, PTs measure and reduce high voltage. PTs require a significant amount of insulation to maintain safety in high-voltage applications, and they’re often found in power distribution networks, transmission systems, and industrial equipment.
Unlike CTs, potential transformers reduce voltage at fixed ratios, ensuring accurate metering and relay operations. They’re especially important in residential electrical systems, where users will want to use different voltages for different systems (an appliance will require a different voltage than ceiling lights for instance). They’re also important for testing purposes, maintaining the safety of the user and the function of the system at large.
About Custom Magnetics, Inc.
Custom Magnetics designs and manufactures custom transformers in a wide variety of different types, like the current transformer or the potential transformer. If you’re looking for a partner in custom magnetics manufacturing, contact us to request a quote and get started.
