Line Tester

[raj151857]

1.How a Line Tester on 230 V or 110 V AC works.( how it glows, what is current path) for the following:
Case I: Delta( Pri 6.6 KV) /Star ( Secy, 415 V ph-ph and 230 V ph-n) Distribution Transformer Secy neutral earthed.Tester put on secy phase wire.Tester glows.What is the current path.
Case II: 415 V Pri and 110 V sec single phase control transformer with one conductor of sec side grounded.Tester put on Secy line conductor.Tester glows.What is the current path.
Case III:415 V Pri and 110 V sec single phase control transformer without grounding any two lines.Tester put on any one of two lines.Whether tester will glow or not.If glows what is the current path.
2.One HT motor of 6.6 kV rating is connected to a step up transformer( 415V star / 6.6 KV Delta) Pri neutral point not grounded.
Motor receives power from Delta side.
Case I:Motor stator body ( equipment earthing not done) not grounded.Due to any voltage leakage on the motor body whether person will feel electric shock or not.
Case II:If we ground the stator body what benefit we will be getting.

 

[Marmite]

Questions that ,quite frankly, to me indicate that you are well out of your depth and need to get expert advice. If the motor case you describe is real I advise you to leave well alone until you receive such advice.
Regards
Marmite

 

[Skogsgurra]

Agree with Marmite.

The current path probably is capacitive coupling. That is not dangerous per se, but trying to do things without understanding what happens usually is.

Gunnar Englund

http://www.gke.org

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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...

 

[Zogzog]

You might want to read this

 

[LionelHutz]

Sounds like textbook questions to me.

You need to describe what type of tester and how it works. Capacitive, direct measurement etc?

Seriously - just think about the last question. Grounding protects against electric shock. Do you need a better benefit??

 

[raj151857]

Am upset as no one is helping me, is any one here to give correct answer.Can anyone help me.

 

[Skogsgurra]

Sorry that you are upset. We could help you better if you tell us what your problem is. It is difficult to believe that you suddenly have all these rather "academic" problems coming up.

We will certainly help you if you describe (at least one of) the problem situations. For instance: "Delta( Pri 6.6 KV) /Star ( Secy, 415 V ph-ph and 230 V ph-n) Distribution Transformer Secy neutral earthed.Tester put on secy phase wire.Tester glows.What is the current path."

What is the real problem? Has anyone got hurt? Has a fire been started? What you describe is perfectly normal and not a problem. Or is it?

Same can be said about your other cases. Sounds like you are trying to cheat at an exam. Apologies if that isn't so. But it surely sounds like it.

Gunnar Englund

http://www.gke.org

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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...

 

[LionelHutz]

You're upset you can't get free help?

You're not getting much help because your questions are vague. For one, we can't tell you why the "tester glows" when we have no idea how that tester works. For another, you talk about things like ungrounded motors but just in a vague application.