Transformer ohmmeter is a line-operated, field portable instrument designed specifically to measure the dc resistance of all types of magnetic windings safely and accurately.
The transformer ohmmeter’s main use is the measurement of the dc resistance of all types of transformer windings within the defined ranges of current and resistance.
The transformer ohmmeter can also test rotating machine windings and perform low-current resistance measurements on connections, contacts and control circuits.
- Direct digital reading
- Built-in discharge circuitry
- Two dependent measuring channels
- Tests operation of on-load tap-changers
Three features that combine to make the transformer ohmmeter unique are dual measurement, load tap-changer testing and safety shutdown.
The dual set of potential inputs measure the resistance of the primary and secondary windings of a single or three-phase transformer simultaneously.
The dual reading characteristic will speed up the measurement when it is used to test windings on delta-delta connected windings on three-phase transformers.
The transformer ohmmeter is available from Megger .