 leiboldPremium,MVM
join:2002-07-09
Sunnyvale, CA
kudos:6
 ·SONIC.NET
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Re: OK, What is this? It is:
- one service disconnect switch (on the primary/utility side)
- one step-down transformer
- one breaker panel / load center (on the secondary/load side)
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Got some spare cpu cycles ? Join Team Helix or Team Starfire! |
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patcat88
join:2002-04-05
Jamaica, NY
kudos:1 | reply to Subaru
Re: What is this? Does it say Norwalk Electric Co or is that just me? |
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patcat88
join:2002-04-05
Jamaica, NY
kudos:1 | reply to AVD
Re: OK, What is this? 480 to 208 transformer? |
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 Subaru1-3-2-4Premium
join:2001-05-31
Greenwich, CT | reply to patcat88
Re: What is this? Yes it does |
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iknowPremium
join:2012-03-25 | reply to Subaru
It looks like you have some good starts to a heavy duty welder, if you modify them!. |
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sk1939Premium
join:2010-10-23
Washington, DC
kudos:9 | reply to leibold
Re: OK, What is this? +1
Looks like that to me, 480V 3 Phase down to 208/240V 3 phase. |
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 Jack_in_VAPremium
join:2007-11-26
Mathews, VA
kudos:1 | Could be 480 volt 1-Ph to 240/120 1-Ph. or 240/120 to 240/120 isolation transformer. You can't possibly look at a transformer like that and determine voltages. |
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sk1939Premium
join:2010-10-23
Washington, DC
kudos:9 | True, but in an industrial application that they are generally used in, I don't see too many single phase devices. |
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Jack_in_VAPremium
join:2007-11-26
Mathews, VA
kudos:1 | said by sk1939:True, but in an industrial application that they are generally used in, I don't see too many single phase devices.
Really? In the large industrial plant I worked in every one of the 240/120 volt transformers was fed from a 480/277 volt single phase distribution panel. 2 phases of 480 3-Ph for the transformers and 1 ph 277 volt for lighting. All of the step down 480 to 240/120 volt transformers were single phase. 3-phase power was only used for electric motors from 1000 hp down to fractional hp. |
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sk1939Premium
join:2010-10-23
Washington, DC
kudos:9 | All the data-centers and schools I've seen have been 3 phase, it really just depends on the area. |
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 John GaltForward, MarchPremium
join:2004-09-30
Happy Camp
kudos:5 | said by sk1939:All the data-centers and schools I've seen have been 3 phase, it really just depends on the area.
All 'modern' facilities use three phase systems. You just don't see single phase panels around anymore in the industrial environment....much along the same lines as high-leg delta systems. |
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 AVDRespice, Adspice, ProspicePremium
join:2003-02-06
Onion, NJ
kudos:1 | FWIW, this unit was in a remote location and might not be on utility power. |
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Jack_in_VAPremium
join:2007-11-26
Mathews, VA
kudos:1
1 edit | reply to John Galt
said by John Galt:said by sk1939:All the data-centers and schools I've seen have been 3 phase, it really just depends on the area.
All 'modern' facilities use three phase systems. You just don't see single phase panels around anymore in the industrial environment....much along the same lines as high-leg delta systems. 13.8 Kv/480 3 phase. 480 volt 3 ph motor control, 480 volt single phase (2 legs) to 277/240/120 single phase. No 208 volt 1 ph. What's so hard to understand? No high-leg to cloud up a simple distribution system.
Three-Phase Transformer Connections:
There are only 4 possible transformer combinations:
Delta to Delta - use: industrial applications
Delta to Wye - use : most common;
commercial and industrial
Wye to Delta - use : high voltage transmissions
Wye to Wye - use : rare, don't use causes
harmonics and balancing problems.
»www.elec-toolbox.com/usefulinfo/xfmr-3ph.htm
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John GaltForward, MarchPremium
join:2004-09-30
Happy Camp
kudos:5 | said by Jack_in_VA:13.8 Kv/480 3 phase. 480 volt 3 ph motor control, 480 volt single phase (2 legs) to 277/240/120 single phase. No 208 volt 1 ph. What's so hard to understand? No high-leg to cloud up a simple distribution system.
Re-read...the point is that most modern electrical systems are three phase. In your area there are probably a lot of old installations.
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»www.archive.org/details/Meatpies_1984
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Jack_in_VAPremium
join:2007-11-26
Mathews, VA
kudos:1 | said by John Galt:said by Jack_in_VA:13.8 Kv/480 3 phase. 480 volt 3 ph motor control, 480 volt single phase (2 legs) to 277/240/120 single phase. No 208 volt 1 ph. What's so hard to understand? No high-leg to cloud up a simple distribution system.
Re-read...the point is that most modern electrical systems are three phase. In your area there are probably a lot of old installations. How about you re-read. I said 3 phase Delta/wye connected which is the most common for industrial and commercial use.
Maybe it's your area that is full of old installations and technology. Why would you throw off on my area? |
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John GaltForward, MarchPremium
join:2004-09-30
Happy Camp
kudos:5 | said by Jack_in_VA: 480 volt single phase (2 legs) to 277/240/120 single phase.
That...you don't see that is modern plants anymore. |
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Jack_in_VAPremium
join:2007-11-26
Mathews, VA
kudos:1 | reply to sk1939
The incoming feed may be 3-phase but it has to be stepped down and split into single phase circuits. I don't think I've seen any 3-phase lights and computers. |
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John GaltForward, MarchPremium
join:2004-09-30
Happy Camp
kudos:5 | reply to Jack_in_VA
Re: OK, What is this? If you're talking branch circuits, that's one thing, but if you're talking distribution, quite another. |
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Jack_in_VAPremium
join:2007-11-26
Mathews, VA
kudos:1 | said by John Galt:If you're talking branch circuits, that's one thing, but if you're talking distribution, quite another.
Just what did you think I was talking about? 3 Phase in and distributed out down to the lowly 120 volt single phase receptacle.
John I know exactly what an industrial power system consists of even down to those with multiple 250 kw redundant feeds to avoid power loss that would cost millions of dollars. Not my plant but one across the street that I have many friends at making nylon and polyester yarn. |
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