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How to size Neutral Grounding Resistor for a Generator, what are the parameters required & how to size?

How to size Neutral Grounding Resistor for a Generator, what are the parameters required & how to size? Topic: Resistor case size
June 16, 2019 / By Aubree
Question: We have 16KV Generator (For 200MVA Unit Capacity) & we have to design NGR size as NGT is not required as per contract, can any one guide
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Best Answers: How to size Neutral Grounding Resistor for a Generator, what are the parameters required & how to size?

Abagale Abagale | 4 days ago
If the generator is 200MVA, I would assume that there is a dedicated generator step-up transformer that isolates the generator from the grid, and that the transformer is connected delta on the generator side, and wye (star) on the grid side. In that case, I would choose 'High Resistance Grounding' for the generator neutral with a rating of about 10a. That would be accomplished using a transformer and a secondary loading resistor. The design objective would be to provide enough ground fault current to control overvoltages in the event of a stator ground fault, while limiting the magnitude of those currents to a level that is not likely to do extensive burning damage for that fault.
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Abagale Originally Answered: How to size Neutral Grounding Resistor for a Generator, what are the parameters required & how to size?
If the generator is 200MVA, I would assume that there is a dedicated generator step-up transformer that isolates the generator from the grid, and that the transformer is connected delta on the generator side, and wye (star) on the grid side. In that case, I would choose 'High Resistance Grounding' for the generator neutral with a rating of about 10a. That would be accomplished using a transformer and a secondary loading resistor. The design objective would be to provide enough ground fault current to control overvoltages in the event of a stator ground fault, while limiting the magnitude of those currents to a level that is not likely to do extensive burning damage for that fault.

Abagale Originally Answered: Can I pack size 0-3 month clothing for my baby's going home outfit or does it need to be size newborn?
For many babies 0-3 month sized clothes are a bit big for the 1st few weeks, it really depends on the size of your baby when they are born. My daughter was 9lb 3oz at birth and only fit in her newborn clothes for a little over a week, I was putting her in all her newborn outfits that had been gifted to us before she could never wear them again, luckily I didn't buy any ourselves. She left hospital in a 0-3 month white babygro as we didn't know the sex this was all we bought, and it fit her fine (albeit the sleeves were rolled up a little and it was roomy). Newborn clothes are designed to fit up to 10lb, while 0-3 months clothes fit up to 14lb (depending on where you buy them). Essentially what I am saying is if you want it to fit perfectly then newborn size will probably be best, but wont last long. 0-3 month clothes will be fine, a bit roomy and may look a bit big, but will still be perfectly okay for your LO, and will last up to 3 months after your LO is born so they can wear the outfit again.
Abagale Originally Answered: Can I pack size 0-3 month clothing for my baby's going home outfit or does it need to be size newborn?
Take 2 going home outfits, a newborn and 0-3 months and then when you come to taking your baby home put the one which fits best on, you don't really know how big or small your baby will be when you give birth.
Abagale Originally Answered: Can I pack size 0-3 month clothing for my baby's going home outfit or does it need to be size newborn?
My daughter was 5 pounds 4 ounces when we were able to finally take her home. The newborns were too small for her so we went out quick and got her a preemie outfit. But most babies are over 7 pounds these days so take the newborn and maybe a 0-3 to be sure:) You could have a big baby!!!

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