Test equipment: HD Electric’s ClearTest Transformer Tester provides quick and easy tests of de-energized power distribution system transformers. It is a handheld device with a single pushbutton that provides a clear indication of open circuits, short circuits, including shorted turns or shorted windings and confirmation that the test results are okay.
The ClearTest is a new design that briefly energizes the transformer and takes a snapshot of the transformer condition by measuring the voltage, current and power factor of the test signal.
The ClearTest finds transformer defects that include:
• A single shorted turn in the primary or secondary side of a transformer;
• Open coils or blown internal fuses or breakers;
• Partial shorts including shorted turns, shorted turn layers, coil to core shorts and primary to secondary shorts; and
• Bad transformer ratios resulting from shorted turns.
ClearTest looks both inside and outside the transformer—testing the coil, core and winding as well as between the transformer and whatever it is connected to.
Transformer tester features include:
• Finds internal transformer defects before energizing;
• One tester for all transformer types;
• Test the primary and secondary sides of de-energized transformers without disconnecting;
• Tests all connections from transformer to meter;
• Improve SAIDI statistics by quickly testing and getting the transformer back in service;
• Prevents line workers from installing a fuse on a shorted transformer;
• Quickly verifies the secondary connections are not shorted;
• Compact, lightweight and easy-to-use;
• Powered by two 9V field replaceable lithium or alkaline batteries;
• Audible alarm confirms successful test;
• Built-in self test; and
• A magnet is included to hold the ClearTest in place while testing.