Transformer Load Tap Changer Control
Transformer tap positions can be changed remotely using the unit’s built-in transformer load tap changer.

This remote-controlled tap changer feature eliminates theneed to manually change a transformer’s step-up and step-down taps.

Resistance Reading Features
Three resistance-reading channels can measure resistance from 1 micro-ohm to 500 ohms, and the test current is programmable (1A, 5A, 10A, 40A).

The LTCA-40 can also be used to measure EHV circuit-breaker contact resistance, motor winding resistance or any low resistance.

If the transformer winding temperature is entered, the LTCA-40 can calculate the equivalent resistance value of the winding material (aluminum or copper) at any standard reference temperature.

Also, a special test mode can run a test for up to 45 minutes while saving resistance readings at one-minute intervals.

AC Motor Current Monitoring
One AC current monitoring channel is dedicated to monitoring the LTC voltage regulator motor current during operation.

The motor current is also printed on the resistance graph and can help detect LTC voltage regulator motor problems.
An AC clamp-on current sensor is provided with the LTCA-40.

Dynamic Resistance Test
One resistance reading channel is dedicated to dynamic resistance testing. This test can monitor the LTC voltage regulator contact resistance during operation. A resistance graph, plotting resistance over time, can be printed on the builtin thermal printer and is very useful for detecting
LTC voltage regulator contact problems.