Testing of current transformer pdf

Testing of current transformer includes: insulation resistance, polarity, burden, magnetization curve, turns ratio and primary injection test. The principal limitation on the sensitivity attainable in any method of testing current transformers is due to the condition that the measuring circuit must not affect the performance of the transformer. This means that the measuring apparatus must not increase the equivalent connected secondary load by more than a. In-service (Burden Injection) testing.

Excitation characteristics verification.

Each CT given RCF and PA data .

Comparator testing as stated in .

Voltage and current comparator testing. With enough bracing, the material flow inside the unit was restricte increasing the possibility of voids. This transformation is made possible by copper coils wrapped around an iron core, with the ratio between primary and . The importance of current transformer tests is often underestimated. As test equipment becomes more sophisticated with better features and accuracy, we risk turning our field personnel into test set operators instead of skilled field service technicians. Abstract: A method for testing electronic instrument transformers is describe including electronic voltage and current transformers (EVTs, ECTs) with both analog and digital outputs.

A testing device prototype is developed. It is based on digital signal processing of the signals that are measured at the . Emphasis is placed on the ability of current transformers to provide accurate operating current at normal system operation and other system disturbance to protective relay systems in high voltage power systems. CURRENT TRANSFORMER TESTING SWP.

Check this is the latest Process Zone version before use. Tests have shown values ranging from 5to . CT when the instrument is removed for test - ing and . It is essential that this instruction book be read thoroughly before putting the equipment in service. Error limits for TPX, TPY and TPZ current transformers.

How to specify current transformers for transient performance. A more accurate calculation can be made if the test reports for the transformer are available. In such case the ratio errors at no- load and at . Correct operation of MPS and FPS relays depends on accurate polarity. Markings on current transformers ( CT ) and potential transformers (PT) have been occasionally misapplied from the factory.

The tests below will assist in confirming polarity in the field. Megger and Power Factor windings, bushing and arrestors. Note: Wait until hours after completion of oil filling for Power Factor testing. Load CT circuits overall and flash for polarity.

Before energization, trip-check . The meter data is transferred to the Retailer for the formulation of the electricity charges in the invoice. The CT is solely assessed through its external behavior without considering what is happening inside. These types of transformers are commonly called wound-type CTs, and have .