Current Transformer Polarity Test

Direct current and a compass.

Current Transformer is an AC transformer,what polarity you talking about ?

Could you explain please.

Nah, not happening, you can mark this off topic to.

A sombrero would appear as the size of a demitasse.

Using a two channel oscilloscope to check the phase rotation may be an option if the CT is not marked with the connection polarity (which it should be).

I'M repeating my question again:

Current Transformer is an AC transformer,what polarity you talking about ?

Could you explain please

Nope.....

I am not joking ,I'm asking seriously:

I'M repeating my question again:

Current Transformer is an AC transformer,what polarity you talking about ?

Could you explain please

The winding direction decides the direction of magnetic flux. It is important to respect the polarity (beginning and ending of the winding) in many cases... please study more information on http://www.kilowattclassroom.com/Archive/TransfPol.pdf

CR4 Admin: disabled broken link

Go to this thread http://cr4.globalspec.com/thread/33197 and see comment # 1.

- MS

See the diagram below. When you flick the lead onto the battery positive, you make A on the primary busbar POSITIVE to
B on the busbar. If the ammeter flicks forward (not backwards to less than zero), you KNOW that "a" goes positive to "b" at
the secondary when A goes positive to B.

You need to respect the size of the CT. If the secondary is rated 5 amp, you start with a 5 amp (or more!) ammeter before
trying the next range/size down (it must be a moving coil DC ammeter, digital meters are no good for this job). Yes, you
can use a coil of wire and a compass to make an ammeter, but that is another story! Do not be tempted to use a voltmeter,
CTs can produce enormous voltages and will burn-out a voltmeter. If you have 2000amp/5 amp CT you will need a 12 volt car
battery (which will give about 200 amps short circuit), for a 50/5 CT a large low resistance manganese torch cell MN1300
or LR20 may do. Have a thought to the need for a resistance to limit the current, at car battery capacity a 100 metre
coil of 1 square millimetre insulated copper cable will give about 2 ohms (do not forget to look in the Electrical Code
on the subject of short time current ratings of cables!). Finally, remember you are dealing with dangerous power, wear
overall clothing, gloves and eye protection because molten metal may fly out of the sparks at the car battery terminal.

you can do that with 9V DC battery and a galavanometer. Connect the galvanomter + to S1 of the CT and - to S2 of CT. Now connect battery '-' to P2 of CT and give a single pulse in P1. If the deflection is at clockwise, polarity is ok.. if its is opposite., its reversed.

-Vijay