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Hello All, I have a question. I have a meter that is showing the peak current in phase B to be double that of peak current phase A & C. Does anyone know what may cause this? In phase B its 190 Amps approximately while in A * C the peak was about 95.

Use stranded or non stranded (soild cables) for power distribution cables? Also, use the same for ground cable?

Anyone know requirements for sizing grounding cable on LV side of a power Xfmr?

I know how many power cables I need based on Xfmr size and LV cable I plan to use. My question is do I need a ground and neutral? My thinking is 216 is line to line voltage but the 125 would be line to neutral so I would need a neutral and a ground. Is this correct?

What does a way mean exactly? Does it mean for each direction power flows? If so, why 3 ways? 6 ways?

What do these terms mean in this type of switch? Load Break? Does that simply mean it can be operated under load? Air Switch? Does that mean that it doesnt have any special insulation such as SF6 etc.? Just operates in atmosphere?

Ground cable size required for MV circuit I am currently designing a power system to use 3 1/C 500 kcmil MV cables. I am doing a calculation to determine the size of conduit required as well as grounding cable size required. I found thread on forum listed here about grounding cable size...

Hello, I have a 13.8 Kv-480/277 V, 1000 KVA Xfmr. Using S = V*I*sqrt(3) I got: I available on primary side = 41.84 Amps I available on secondary side (Using 277 Volts) = 2,084 Amps My questions: 1) Do I simply take 41.84 Amps (I on primary side) and multiply by 1.25% = 52.3 Amps and choose...

In my research on open versus closed transition switching, I fount this: Open Transition Transfer Switches An open transfer switch’s connection with a generator is established before the utility is shut off, and then the swap is made quickly once the connection has been safely established. Open...

Hello all, Not a electrical theory question but related. Typically when working with vendors I have had great responses and they have been good to work with to accommodate my project needs where they can. However, a couple months ago I contacted a rep. for a major supplier in area our...

Hello Fellow Engineers, I am currently working on a project to replace several power Xfmrs that are located in vaults. So an issue is whether or not the new Xfmrs will even fit in an existing vault or vault will need expanded. I have asked for preliminary quote with dimensions. However, I got...

What is purpose of working space requirements in NEC? Is it basically a safety zone provided when working on a panel when doors are open (energized)? What about in case of working on either primary side or secondary side of a Xfmr? Is it required on each side for same reasons? THanks for any...

Hello All, I am reviewing NEC Classified area section. Something came to my mind from days at chemical industry but could not find answer. So, does anyone know how, when developing a HAC drawing, to tell how far the classified area extends beyond the source/point? Thanks!

What does it mean when someone says 5 sets of 500 kcmil? Does this mean 5 500 kcmil cables per phase? So say the cables are 100' long then you would need 1500' of cable?

If a Transformer is listed at 12470Y/7200 Primary and 480Y/270 secondary (Shown AS 12470Y/7200V for primary and 480Y/270 secondary) does this mean the primary must be wired in a Y configuration if to be used at 12470 V and if you use a neutral on the primary then it would be 7200 V? With the Y...

Often I see power cables in cable tray tri-plexed. If there a reason for this like makes the power flow more efficient? Thanks!

Hello folks, Just have a general questions. Its in regards to grounding cable tray. If you have a long run of cable tray that is properly grounded. I understand that grounding is in case a cable that's on the cable tray becomes shorted it will allow current to flow to ground until breaker...

If you have a net neutralization potential of 40-tons CaCO3/1000 tons of waste and your neutralization potential to acid generation potential ratio of 5:1, what is your net neutraization potential on ton CaCO3/100 tons of waste?

I have a mapscale question....I am trying to calculate surface area of a pond and creat a stage storage curve from this info.....The question says my map scale is a 500 scale...it tells me I have a 42.34 square inch surface area....what would be the surface area in acres...? I tried...

If I want to know how much Gold is being electroplated onto Carbon during an electroplating example, how would I calculate this? Use Faradays law or other techniques?