How Does The Power Fittings Measure The Polarity Of The Current Transformer Using The Dc Method?

Load isolation switch How to measure the polarity of current transformer using DC method?
The method of measuring the polarity of current transformer using DC method is as follows
(1) Connect the "ten" pole of the battery to L1 of the primary measurement of the current transformer, and the "one" pole of the battery to L2.
(2) Connect the "ten" pole of the multimeter to K1 of the secondary measurement of the current transformer, and the "one" pole to K2.
(3) When the switch is closed or the battery is connected, the milliampere block indication of the multimeter should deflect from zero to the positive direction. When the switch is opened or the battery is disconnected, the multimeter pointer deflects in the opposite direction, then its polarity is correct.
What measures should be taken to reduce the voltage drop of the secondary conductor of the power hardware voltage transformer?
To reduce the voltage drop of the secondary conductor of the power hardware voltage transformer, the following measures should be taken.
(1) Lay the secondary circuit control cable dedicated to the electric energy meter.
(2) Increase the wire cross section.
(3) Reduce the series connection points of the transfer bridge.
(4) Use a voltage error compensator.