Whats happening here?

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Smart $ said:
Assuming that panel has a 100A MCB and rated for 75°C terminations, the minimum is #3.
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Thanks for the answer but i was not looking into code,just by looking at the wire can you tell what the wire size is?For me it looks a little bit more than #3.
 
shoaib10 said:
Thanks for the answer but i was not looking into code,just by looking at the wire can you tell what the wire size is?For me it looks a little bit more than #3.
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Pictures can be deceiving. I could judge better if I were there in person, but I dare not hazard a guess based on the two pictures provided.

Now if you put a scale up against the conductors and took a picture and posted it, I might hazard a guess.
 
mrgabriel.acuna said:
There should be markings on the wire at least every foot as to the size and type of insulation.

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Unfortunately i wasnt able to get that information...I was just trying to see is the wire size close to #3 or #2 just by physically looking at it..
 
shoaib10 said:
Not me...:happyno:..I am working on SC study to give them these labels so that they can work on it wearing some gear..
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Don't mean to come across the wrong way here, but how is it you understand the complexities of calculating fault current but can't figure out how a "polaris tap" works?:?




JFletcher said:
Are there any wild leg 480V services that have B phase 416V to neutral?
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Absolutely.


Smart $ said:
In what limited experience I have with 'em, mostly for 3Ø motor loads, and the center tap just provides for grounding the system rather than running corner grounded or ungrounded with a detector.
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Correct.

Same reasons you sometimes see them on 240 volt services. Limited load applications, in a remote area, little of both. The math is the same, draw an equilateral triangle with 480 units of measure per side, with a mid point reference on one side. The distance from that midpoint to the opposite corner is 1.732 times the distance to an adjacent corner.

120 x 1.732 = just under 208

240 x 1.732 = just under 416

A lot of irrigation machines in this area that are single load services, only 10 to 15 kVA max and they put them on open delta configured systems. They can corner ground them, but anymore the POCO would rather ground the mid point of one phase. Too many non professionals getting their hands on corner grounded systems and not understanding what they are or how they work is more hazardous then having a high leg system. And that happens all too frequently with farming applications.
 
my_mail_hub said:
Not that I am aware of. If it is a delta, with a neutral derived between phases will give a reading "like" 285v, instead of 277v between the B or C phase and neutral or ground. If it is a corner grounded delta, you won't get any voltage reading on the grounded phase to neutral or ground, but will still read 480v to neutral or ground on the other legs.
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No, if it is a high leg delta system the midpoint of one side of the delta is what is grounded. Presuming nominal of 480 volts, that means each side of the midpoint is 240 volts, not 277, not 285, and the opposite corner (the high leg is 416).

480/277 wye systems that are operating at about 493 volts line to line will read about 285 to neutral, but that is just proportional raising of each measurement point as the overall voltage is increased. Many POCO will bump voltage up to around 500 in unloaded condition so that when loaded it hopefully doesn't go much below 480.
 
shoaib10 said:
Unfortunately i wasnt able to get that information...I was just trying to see is the wire size close to #3 or #2 just by physically looking at it..
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According to Ilsco part drawing, that connector is 3.024" wide. Using my graphics program I took the ratio of connector width to smaller conductors width and came up with a diameter of .584". If that's THHN it would be #3/0.... commonplace for a 200A panel.
 
The reason you get a wild leg higher than 277 on a delta is because there is no true neutral point on the coil. I think you need to go back rethink what you have stated. A wye has a true neutral point. That 416v you are referring to are on a rarely used type of delta that was already mentioned above. I was referring to a standard delta.

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my_mail_hub said:
The reason you get a wild leg higher than 277 on a delta is because there is no true neutral point on the coil. I think you need to go back rethink what you have stated. A wye has a true neutral point. That 416v you are referring to are on a rarely used type of delta that was already mentioned above. I was referring to a standard delta.
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You seem to have been referring to a wye, not a standard delta, whatever that is.

I don't know what you mean by a 'true neutral point', but the NEC definition includes the neutral on one phase of a high-leg delta.

Neutral Point. The common point on a wye-connection in a
polyphase system or midpoint on a single-phase, 3-wire
system, or midpoint of a single-phase portion of a 3-phase
delta system, or a midpoint of a 3-wire, direct-current
system.
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kwired said:
Don't mean to come across the wrong way here, but how is it you understand the complexities of calculating fault current but can't figure out how a "polaris tap" works?:?
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I just got into the field a year ago and since then i have been working on the SC study..I am still under training though...As far as polaris tap that's the first time i have seen them..There's no harm in asking something you dont know even if its a simple question..We are all here to learn...:thumbsup:
 
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jaggedben said:
You seem to have been referring to a wye, not a standard delta, whatever that is.

I don't know what you mean by a 'true neutral point', but the NEC definition includes the neutral on one phase of a high-leg delta.
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If you dont understand what a true neutral point is on a transformer coil, I would suggest that you read more and post less.

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Smart $ said:
According to Ilsco part drawing, that connector is 3.024" wide. Using my graphics program I took the ratio of connector width to smaller conductors width and came up with a diameter of .584". If that's THHN it would be #3/0.... commonplace for a 200A panel.
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That's the bigger wire size.You are right i have the information for the bigger of the three wires which is 3/0 i am looking for the other two smaller wires..Can you determine those wire sizes?They look smaller than 3/0 to me.And if possible can you share the work you did?I just want to see how to do those..May be a screen shot or something.That would help me a lot..
 
my_mail_hub said:
If you dont understand what a true neutral point is on a transformer coil, I would suggest that you read more and post less.
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If you can't describe a high-leg delta accurately and precisely, then I would suggest the same to you. A neutral on a high-leg delta is as 'true' with respect to the phase it's on as any other neutral. (What kind of neutral point isn't 'true?) At least admit it if you just typed the wrong word by accident (delta instead of wye, for example).
 
shoaib10 said:
That's the bigger wire size.You are right i have the information for the bigger of the three wires which is 3/0 i am looking for the other two smaller wires..Can you determine those wire sizes?They look smaller than 3/0 to me.And if possible can you share the work you did?I just want to see how to do those..May be a screen shot or something.That would help me a lot..
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#3/0 is what I got for the smaller conductor (innermost orange-taped one). If the center one is definitely #3/0, then it just goes to show you why I typically do not try to hazard a guess just from looking at a couple pictures.
 
jaggedben said:
If you can't describe a high-leg delta accurately and precisely, then I would suggest the same to you. A neutral on a high-leg delta is as 'true' with respect to the phase it's on as any other neutral. (What kind of neutral point isn't 'true?) At least admit it if you just typed the wrong word by accident (delta instead of wye, for example).
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I already did. If you can understand what you read, I suggest a dictionary and some practice.

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If this thread does not move on from impolite bickering it will be closed.
Which would be unfortunate since the OP still appears to have questions.
 
ggunn said:
Then why don't you enlighten us instead of posting snarky remarks?
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I wasn't snarky before, but if you'd like I can be. I didn't come at anyone with reproof before hand. I wasn't even questioned, I was rudely told I was wrong. I simply, concisely, and pointedly stated a rebuttal. I guess I'll have to start posting pictures of what I'm talking about since you're reading comprehension is not up to par.

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