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macgyver655
Joined: 22 Aug 2007 Posts: 8508
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Link Posted: Fri Jan 22, 2010 3:05 am Post subject: |
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Boilermaker wrote: |
Quote: | But there is also an issue of the safe way to do things. |
Could you please be more specific on this issue?
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I made this comment based on the issue that if there is not a specific code on a certain install that the install should still be done safely.
Or if a local authority in the back woods of bum _uck wherever never adopted a code, safety should still be applied.
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Nashou66
Joined: 12 Jan 2007 Posts: 16171 Location: West Seneca NY
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Link Posted: Fri Jan 22, 2010 3:06 am Post subject: |
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macgyver655 wrote: | Boilermaker wrote: |
Quote: | And the electrical requirements is so different from residential, that not many residential electricians understand what needs to be done. |
Yes! Its a whole different world.
Bob |
They are not as different as you think. I have the 2008 NEC code book which is the current issue. Requirements on separate derived power has strict requirements in all facets of installation.
Read it for yourself. I have..... |
You Might be reading something Bob wrote.
Nashou
_________________ Don't blame your underwear for your crooked ass~ unknown Greek philosopher
"Republicans believe every day is the Fourth of July, but the Democrats believe every day is April 15." --- President Reagan
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mp20748
Joined: 12 Sep 2006 Posts: 5681 Location: Maryland
TV/Projector: 9500LC Ultra / Super 02 and 03 VIM
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Link Posted: Fri Jan 22, 2010 3:12 am Post subject: |
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Quote: | This is not fully correct. the engineers may rwrite the requirements for their equipment but that requirement can well exceed the NEC code. Code may say that only 1 rod is required to pass code but the engineer may feel the its equipment is better protected with 3 rods. This does not change NEC code and it would not fail because code may not require all 3. But it is in the best interest to follow manufacturers code unless it differs from local code.
The same goes that local code can call for 3 rods but the manufacturer may only call for 1. 3 would have to be installed to pass code even if only 1 is required by the engineers.
The licensed electrician only has to know local code. He doesn't have to know manufacturers requirements, but should try to install as per the manufacturer, again as long as it doesn't affect local code. |
When I refer to a system, I'm talking about an engineered system that's comprised of various different manufactures equipment. So it's not a "manufacture" it's an engineered system that has special environmental and electrical requirements that depend on that particular system.
Those requirements is what the engineers determines based on: demand, safety and compliance. And they are NEVER separate or different from the code. They will always meet the minimum code requirements.
So if the design calls for a 3 rod grid, and the code is only for one, than the additional 2 rods would not go against the code, because the requirement would be for at least one rod, not just one rod.
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macgyver655
Joined: 22 Aug 2007 Posts: 8508
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Link Posted: Fri Jan 22, 2010 3:16 am Post subject: |
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mp20748 wrote: |
So if the design calls for a 3 rod grid, and the code is only for one, than the additional 2 rods would not go against the code, because the requirement would be for at least one rod, not just one rod. |
You must of misunderstood what I said mike. Because thats exactly what I said. You can increase from what code says, you just cant decrease from code.
Didn't I say that if code calls for 1 and you install 3 that it would pass?
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macgyver655
Joined: 22 Aug 2007 Posts: 8508
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Link Posted: Fri Jan 22, 2010 3:18 am Post subject: |
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Nashou66 wrote: | macgyver655 wrote: | Boilermaker wrote: |
Quote: | And the electrical requirements is so different from residential, that not many residential electricians understand what needs to be done. |
Yes! Its a whole different world.
Bob |
They are not as different as you think. I have the 2008 NEC code book which is the current issue. Requirements on separate derived power has strict requirements in all facets of installation.
Read it for yourself. I have..... |
You Might be reading something Bob wrote.
Nashou |
Say what?
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macgyver655
Joined: 22 Aug 2007 Posts: 8508
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Link Posted: Fri Jan 22, 2010 3:20 am Post subject: |
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This is what I said Mike.
Quote: | This does not change NEC code and it would not fail because code may not require all 3. But it is in the best interest to follow manufacturers code unless it differs from local code that decreases safety. |
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Boilermaker
Joined: 21 May 2006 Posts: 527
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Link Posted: Fri Jan 22, 2010 3:31 am Post subject: |
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Mac,
Quote: | For example, if the NEC code says one thing and a local authority says something else then the local authority rules under the law. However, if that rule is contradicted by county or state rule, then the higher would apply, under the law. |
In every state, the state's Fire Marshall is the final authority for the ENTIRE state.
Quote: | They are not as different as you think. I have the 2008 NEC code book which is the current issue. Requirements on separate derived power has strict requirements in all facets of installation. |
You have misread what I said. I referred to mike's comment Quote: | that not many residential electricians understand what needs to be done | .
Quote: | Read it for yourself. I have..... |
I really don't need to read it, as I helped write it. Not the 2008, but several previous ones, restricted to the healthcare section.
Bob
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lovebohn
Joined: 16 Mar 2006 Posts: 181 Location: Wisconsin
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Link Posted: Fri Jan 22, 2010 3:32 am Post subject: |
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So is everyone agreeing to disagree on this subject?
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macgyver655
Joined: 22 Aug 2007 Posts: 8508
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Link Posted: Fri Jan 22, 2010 3:42 am Post subject: |
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Boilermaker wrote: |
I really don't need to read it, as I helped write it. Not the 2008, but several previous ones, restricted to the healthcare section.
Bob |
AT this point Bob I will refrain from pointing out some of the comments you made as being different from current code. Its still bothers me on some of the suggestions you made on certain things but again, what do you want me to say. I visually saw things in lovebahns and athan boxes that concern me but you didn't comment. This is what concerns me about your comments. But it appears this is neverending so I'll leave it to pan out however. And hope for the best for all.
If you say you helped write the healthcare section thats great, but there are other sections that clearly apply to residential use that indicate otherwise.
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macgyver655
Joined: 22 Aug 2007 Posts: 8508
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Link Posted: Fri Jan 22, 2010 3:52 am Post subject: |
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Boilermaker wrote: |
In every state, the state's Fire Marshall is the final authority for the ENTIRE state.
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Unless you have a document that says otherwise, this one says the local authority in the final authority which is what I have always read.
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macgyver655
Joined: 22 Aug 2007 Posts: 8508
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Link Posted: Fri Jan 22, 2010 4:18 am Post subject: |
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Boilermaker wrote: |
In every state, the state's Fire Marshall is the final authority for the ENTIRE state.
Bob |
This also doesn't make sense because if a local authority does not adopt the code then the state marshal cant enforce it in that location.
Now, if you meant the local fire marshal for that location then he would have the same authority as the code enforcement officer which is to uphold the local code.
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macgyver655
Joined: 22 Aug 2007 Posts: 8508
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Link Posted: Mon Jan 25, 2010 5:48 am Post subject: |
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Boilermaker wrote: |
In the case of your subpanel, after you install your xfmr. your ground and neutral will be completely isolated wjich is why it is considered a separately derived source, just as though it came from a different power company.
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I wasn't going to comment anymore in this thread but this part has really been bothering me and if others read this it becomes an issue.
This procedure is a direct violation of NEC code. This is only allowed in healthcare facilities.
NEC code requires that in a separately derived system on the secondary side the neutral be bonded to ground and connected to the main premises ground. Except in healthcare facilities.
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greg_mitch
Joined: 03 May 2006 Posts: 5321
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Link Posted: Mon Jan 25, 2010 5:56 am Post subject: |
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macgyver655 wrote: | Boilermaker wrote: |
In every state, the state's Fire Marshall is the final authority for the ENTIRE state.
Bob |
This also doesn't make sense because if a local authority does not adopt the code then the state marshal cant enforce it in that location.
Now, if you meant the local fire marshal for that location then he would have the same authority as the code enforcement officer which is to uphold the local code. |
Just recently passed a law in Iowa that gives State power over all cities. We do work in so many cities that don't have codes...now they all have to abide by the State adopted codes/regulations.
This is similar to other states. The state authorities can usually override any local guy.
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macgyver655
Joined: 22 Aug 2007 Posts: 8508
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Link Posted: Mon Jan 25, 2010 3:50 pm Post subject: |
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greg_mitch wrote: | macgyver655 wrote: | Boilermaker wrote: |
In every state, the state's Fire Marshall is the final authority for the ENTIRE state.
Bob |
This also doesn't make sense because if a local authority does not adopt the code then the state marshal cant enforce it in that location.
Now, if you meant the local fire marshal for that location then he would have the same authority as the code enforcement officer which is to uphold the local code. |
Just recently passed a law in Iowa that gives State power over all cities. We do work in so many cities that don't have codes...now they all have to abide by the State adopted codes/regulations.
This is similar to other states. The state authorities can usually override any local guy. |
Thats good that they did that if there were many areas that didn't have any code. Specific law would be required to do so. Do you have a law number? I would like to read it.
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macgyver655
Joined: 22 Aug 2007 Posts: 8508
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Link Posted: Mon Jan 25, 2010 9:25 pm Post subject: |
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greg_mitch wrote: | macgyver655 wrote: | Boilermaker wrote: |
In every state, the state's Fire Marshall is the final authority for the ENTIRE state.
Bob |
This also doesn't make sense because if a local authority does not adopt the code then the state marshal cant enforce it in that location.
Now, if you meant the local fire marshal for that location then he would have the same authority as the code enforcement officer which is to uphold the local code. |
Just recently passed a law in Iowa that gives State power over all cities. We do work in so many cities that don't have codes...now they all have to abide by the State adopted codes/regulations.
This is similar to other states. The state authorities can usually override any local guy. |
I have searched high and low for this new law and could not find it. What I did see is were Iowa has adopted some updates to the state code. But that doesn't affect local authority. This is what I did find under Iowa law.
"Iowa Code Chapter 103A allows jurisdictions to adopt other building codes or to use no code."
Now this may of been changed as you said but I cant find any reference to that.
I have yet to see any state law that forces local authority to do something but I'm sure it maybe possible. I would like to see such a law if it does exist though. I like to read new stuff.
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greg_mitch
Joined: 03 May 2006 Posts: 5321
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Link Posted: Tue Jan 26, 2010 2:34 am Post subject: |
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I haven't ran into it personally but it was just announced at our monthly dept. meeting. I will get the specifics.
Of course, depending on what you are talking about there is usually a state authority who has jurisdiction...especially in Illinois.
The Dept. of Health is pretty darn powerful. The State Plumbing guys, elevator guys, etc. all have final say over any regional or city authority in almost every case. Whether it is merely by influence or direct written rule, I don't know.
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gattaca
Joined: 28 Nov 2011 Posts: 20
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Link Posted: Mon Nov 28, 2011 5:03 am Post subject: Sizing an isolation transformer for AV |
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HI,
I've followed this thread and thank you for the general education! It's been great! BTW, that HP Isolation Transformer discussed much earlier is a really NICE unit! It came out of a very old HP computer that was built like a tank.
I have a personal project I've been thinking about for a while which involves adding 2 x Isolation transformers to my AV setup. However, I need to start looking for the parts to do this as it may take a while to locate them.
My questions are related to sizing mostly:
1) If I have a chance to buy a .005pF or .0001pF unit, which unit should buy? I know the .0001pF units have like 146 dB of noise suppression where the .005pF unit has 125 or so dB but what's good enough vs. what's the best as there is a 2x cost delta between these two units from what I've seen. Is that added delta really worth the added costs? I know the figures are substantial but ... gotta ask.
2) Presently I have 2 x 20A / 12Ga Circuits feeding the AV setup which uses no where near that amount of power. I have just a couple of efficient amps, a receiver, and a DLP setup- mostly each 20A is barely loaded. Recently, I had a chance to buy 2 x 7.5kVA units at .0001pF as a set but passed b/c I did not know if I can safely use them on my existing 20A circuits. For the sake of discussion, if the loads on these are say 2-12A, do I have to be concerned that the isolation transformer input side is rated at 5kVA? I mean, my AV setup is not going to draw that kind of juice on the output side.
My question is...the ISO is not going to draw 5kVA of power unless there's a 5kVA of load correct? Except perhaps on turn on which I can control with thermal slow starts. Whatever load is on the output is what will be on the inputs +/- efficiency loss correct?
Ideally, I'd be looking for 1.8 - 2.5 kVA units but I see more 5 kVA units available is why I'm asking.
3) For mounting these units, what do you recommend? Bolting to the floor? Putting on isolation pads? I've read they can be quite noisy from the vibration. My two units would be located downstairs in the basement but I really don't want to hear a "hum" coming up the stairs?
Thanks, Vincent
Last edited by gattaca on Sat Dec 03, 2011 8:43 pm; edited 1 time in total
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Nashou66
Joined: 12 Jan 2007 Posts: 16171 Location: West Seneca NY
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Link Posted: Mon Nov 28, 2011 6:38 am Post subject: |
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One 5kva unit would be more than enough for a typical Home theater. Think of it as having your own power company that no one else is connected to. It will only draw what you load it with.
Id just let it sit on the floor on a rubber pad to help with noise isolation, mine is not too loud.
Mine is fed with 220 via 8 gauge wire and can load up to 44 amps. I can put everything on in the theater and the 8 gauge wire feeding it does not even get warm.
Just make sure you have the appropriate size breakers in the main panel box feeding it.
I love mine.
Also keep it well ventilated as it can get warm to hot.
Oh and welcome to the forum Vincent!
Athanasios
_________________ Don't blame your underwear for your crooked ass~ unknown Greek philosopher
"Republicans believe every day is the Fourth of July, but the Democrats believe every day is April 15." --- President Reagan
One Smart Dog!!!
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gattaca
Joined: 28 Nov 2011 Posts: 20
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Link Posted: Sun Dec 04, 2011 12:06 am Post subject: |
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Athan, Bob, Gary, ...
Biting the bullet on a long awaited project - called my electrician last week and scheduled a small job when he has a slow afternoon.
I've read the thread. I have a few questions. Please forgive the length.
Below items are for discussion only. All items should be reviewed by a licensed professional.
1) 5kVA 240/120V 50/60Hz Topaz IsoT with the following:
Plate Diagram:
H1 --* %%% -- H2
H3 --* %%% -- H4
Gnd (shield)
X1 --* %%% -- X2
X3 --* %%% -- X4
Gnd (shield)
Code: | Plate w/ unit reads:
Input Jumper Term
120V H1 & H3 H1 & H4
H2 & H4
240V H2 & H3 H1 & H4
Output Jumper Term
120V X1 & X3 X1 & X4
X2 & X4
240V X2 & X3 X1 & X4 |
Presently there are 2 x 20A dedicated circuits feeding an AV setup located about 60' from two separate 200A Main panels.
2) A smaller 125A sub-panel will be installed to connect power from the IsoT outputs to these 2 x 20A existing dedicated drops.
3) I reviewed this thread. There are several methods of connecting this type of IsoT:
a) the secondaries in parallel
b) the secondaries in series
c) the secondaries in balanced mode
I would like to understand the reasons why Athan connected his as he did. It seems to be related to supplying the AV setup from the SAME Phase, which I've read, drops the noise floor. However, then I read the discussion about supplying the subpanel differently. Then I read the balanced discussion.
4) While Googling, I located several other connection options which would be good to understand the pros/cons of:
a) a reference from Middle Atlantic, specifically, page 21.
-> http://www.middleatlantic.com/pdf/PowerPaper.pdf
b) A reference from Torus Power's 240V series using Plitron Toroids:
-> http://www.toruspower.com/wp-content/uploads/2011/09/25Kschematic.png
c) a reference for another MGE IsoT model, page 2-5:
-> http://printfu.org/read/installation-and-user-manual-b73f.html?f=1qeYpurpn6Wih-SUpOGumK2nh7Xd6dnV1NHR5tLd4obW28mMxOnK5oiy0eDez-CIsOCfnqmY2eiKoOOsmp-uiN_i2ODc5rXEzdHVlKThrpevj8uOqumfp6Gfktrd4uSgpJzY5eLa1NeWyd_h2-Giyd2csrO0pdmlmJXd09fjotbZ04en7A
5) For discussion, what remains unclear is what the deltas / pros / cons are between these options:
a) Input on a 5kVA Topaz. 5000VA/240V * 125% = Dual 30A. For 7500VA/240V * 125% = Dual 40A
a1) H3 <----> H2 jumper
a2) H1 <----- dual breaker <- 240V main panels.
a3) H4 <----- dual breaker <- 240V main panels.
a4) GND <--- Existing Main Panel GND
b) Output (120V 0V 0V 120V) "Center-tapped"
b1) X1 -----> L1 in new subpanel (120V @ ~ 20A)
b2) X4 -----> L2 in new subpanel (-120V @ ~ 20A)
b3) X2 -----> GND BAR inside IsoT -> Isolated Neutral in new subpanel
b4) X3 -----> GND BAR inside IsoT -> Isolated Neutral in new subpanel
b5) GND -> GRD BAR inside IsoT -> Isolated GND in new subpanel
c) Output (120V 120V 0V 0V)
b1) X1 -----> L1 in new subpanel (120V @ ~ 20A)
b2) X3 -----> L2 in new subpanel (120V @ ~ 20A)
b3) X2 -----> GND BAR inside IsoT -> Isolated Neutral in new subpanel
b4) X4 -----> GND BAR inside IsoT -> Isolated Neutral in new subpanel
b5) GND -> GND BAR inside IsoT -> Isolated GND in new subpanel.
d) Output (120V 0V)
b1) X1 -----> Jumper -> X3 -> L1+L2 in new subpanel (120V @ ~ 40A)
b2) X2 -----> Jumper -> X4 -> N1+N2 (Isolated) in new subpanel
b3) X2 -----> Jumper -> X4 -> GND BAR inside IsoT
b4) GND-> GND BAR inside IsoT -> Isolated GND in new subpanel
6) Does (b) produce 120V@20A on X1 and -120V@20A on X4 and the Neutrals are the center-tapped X2@20A+X3@20A?
7) Does (c) produce 120V@20A on X1, 120V@20A on X3 and the Neutrals are X2@20A+X4@20A?
Will both legs be in the same phase?
8) Does (d) produce 120V on X1+X3 @ ~40A and the Neutrals are X2+X4@40A?
9) One could also opt to use the Topaz to generate balanced power (60V/-60V) with a 120V input but that opens another can of NEC related worms already discussed earlier.
10) What sort of isolation pad would be good for these as I have a feeling them resting directly on a concrete slab is going be loud and transmit vibrations to the slab. These weigh about 100+ lbs.
11) The final goal is similar to one of Gary's earlier posts. This is a first step.
5kVA IsoT -> 1 x 120V / 20A -> APC Smart Sine-wave UPS -> SurgeX NoMOV -> Balanced Power Xformer (in cabinet) --> Components A
-> 1 x 120V / 20A -> APC Smart Sine-wave UPS -> SurgeX NoMOV -> Balanced Power Xformer (in cabinet) --> Components B
12) Comments? Thoughts? Pros, Cons?
Above items are for discussion only. All items should be reviewed by a licensed professional.
Thanks, Vincent
Last edited by gattaca on Sun Dec 04, 2011 6:16 pm; edited 26 times in total
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Nashou66
Joined: 12 Jan 2007 Posts: 16171 Location: West Seneca NY
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Link Posted: Sun Dec 04, 2011 1:02 am Post subject: |
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I don't think you'll need to go balanced power as it really only benefits if you match the equipment being powered from both sides, or at least thats how I understand it, its difficult to match it what I am saying.
I think what you want to do would work best if you knew each component on each balanced side was drawing the same power, so unless you had a true balanced system where each component on each side of the power leg used the same power draw it would not be beneficial. Or at least thats what I got form the response to Gary's comment of me going balanced.
I have my HP Xfrmer and then I have a medical grade Xfrmer after that for my Video components.
I don't think you have the output right you should jumper X1-X3 and X2-X4 for 120 volt outs. Then hook up X1 to one side of Panel Bus either the neutral or line it doesn't matter as Bob Mentioned. You can do it with white and black as Bob said to Look proper( White to neutral Bus black to Hot Buss) and X4 to the other buss. Now you'll have to take the one Conductor not connected to the neutral Buss and jump it to the other hot side in your panel. Connect the ground from the Xfrmer output side to the Sub Panel ground bar.
I'm not 100% on this as Bob was the one who held my hand the whole way. I'll give him a call to post here and correct me if I am wrong and more insight to the whole balanced power thing.
Athanasios
_________________ Don't blame your underwear for your crooked ass~ unknown Greek philosopher
"Republicans believe every day is the Fourth of July, but the Democrats believe every day is April 15." --- President Reagan
One Smart Dog!!!
Marquee High Performance Bellows now shipping!!
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