6 throw breaker panel

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  #41  
Old 07-19-16, 11:12 AM
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The 4 wire feeder into the house has been required for as long as I can remember.
 
  #42  
Old 07-19-16, 11:42 AM
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If thats the case. Would I have to add a ground bar in the sub panel? Looking back at my picture of the sub panel it appears that all neutrals and grounds have been connected to the same bar? Also, this sub panel is in the same building as the main panel if that makes any difference.

In the last picture I posted on Page 1, will a 2-2-2-4 SER cable be the correct to use? I also just realized that I would not have a dedicated breaker in the sub panel the way it is currently wired up. Is it better to have the dedicated breaker in both panels or only in the main panel?
 

Last edited by joshua5438; 07-19-16 at 12:00 PM.
  #43  
Old 07-20-16, 11:44 AM
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If thats the case. Would I have to add a ground bar in the sub panel? Looking back at my picture of the sub panel it appears that all neutrals and grounds have been connected to the same bar? Also, this sub panel is in the same building as the main panel if that makes any difference.
Yes, the subpanel needs to have a separate ground bar. The neutral bus must be isolated from the panel box and all neutrals and grounds kept separate on their respective bars. Since the subpanel is in the same building, the subpanel can be either a Main Lug Only (MLO) panel or a Main Breaker panel. If you are replacing the subpanel with a new one, I would suggest buying a 100 amp main breaker panel for convenience as a main disconnect at the subpanel, but a disconnect is not required. I also suggest bringing the grounding to current code. You contractor should know how to do that. In addition, I prefer an instersytem bonding bridge be installed too for cable TV, telephone, dish systems, etc.
 
  #44  
Old 07-20-16, 02:35 PM
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Thanks. If I keep the sub panel and only replace the main and feed to sub panel what would I need to do, add a ground bar and separate? Would the sub panel need its own ground rod?
 
  #45  
Old 07-21-16, 12:13 PM
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Another question since I am in the mood to learn about this stuff.. haha. If this is the wire callout 2-4 al 1-4 al type SE cable style U type XHHW condos 600 volt Cerro, do I used the lower or middle temperature rating? According to all the charts I see the XHHW is rated for the middle rating but not sure if thats how you look at it...
 
  #46  
Old 07-21-16, 06:40 PM
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SE cable is used at the 60 degree ampacity .

A sub panel in the same structure as the service does not need a main breaker or a ground rod.
 
  #47  
Old 07-22-16, 06:45 AM
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What does the SE stand for, service entry? I replaced the breaker with a 60A for the time being, until I get the electrician out to switch the main panel. So the wire I have is a HH wire but it can only be rated at the lower lever because its also a SE? Just making sure I understand...

If the sub panel does not need a ground rod.... The feeder will connect from the main panel to the sub panel connecting the two hots, neutral and ground. Since the ground and neutral are tied together at the main panel, technically its the same as only having a three wire system? I understand code actually calls for 4 wire feeder now but trying to understand what the separate ground and neutral accomplish? Is it the fact that the ground bar is not attached to the sub panel so it actually carries back to the main panel? Once it hits the main panel, what stops it from going back thru the connected neutral and then to the sub panel?
 
  #48  
Old 07-22-16, 10:35 AM
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To the best of my knowledge SE stands for Service Entrance. Although the insulation on the individual wires is rated at 90[SUP]o[/SUP] C. because it is a cabled assembly rather than individual wires in conduit it must, by rule, be rated in the 60[SUP]o[/SUP] C. column.

Neutral and equipment grounding conductors are separate everywhere except at the service panel to prevent neutral currents from flowing on the grounding conductor. The only time current flows (or is supposed to flow) on a grounding conductor is during fault conditions and then only long enough to trip the overcurrent protection (fuse or circuit breaker) for the particular branch circuit. Having the equipment grounding and neutral conductors connected anywhere but at the service panel creates a parallel path for the neutral currents AND imposes a portion of the neutral currents on any metallic item (faucets or any cabinet of an electrical appliance that is "grounded") creating a shock hazard.

Equipment grounding is a VERY complicated subject and entire books have been written on the subject. I don't claim to be any kind of expert in that field but if you have further questions, please ask and I or some of the others will attempt to explain.
 
  #49  
Old 07-22-16, 11:08 AM
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Thanks for the clarifications.. I am slowly understanding more and more about how it all works together. The label is on the sheathing that all three wire are in. The individual wires do not have any marking on them. Does that make any difference?
 
  #50  
Old 07-22-16, 11:37 AM
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The individual wires do not have any marking on them. Does that make any difference?
I don't think so. If I remember correctly the rule stating that cable assemblies be limited to the 60[SUP]o[/SUP] C. column is fairly recent, within the last ten years or so. Prior to that the listing would be consistent with the insulation class as denoted on the cable label.

So, it probably would have been okay to use the higher Ampacity at 75[SUP]o[/SUP] C. when the house was built but today it must be limited to the 60[SUP]o[/SUP] C. column. The electrical code is ever evolving as problems arise.
 
  #51  
Old 07-22-16, 11:59 AM
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Makes since. So by code I am ok with the 60A since my wire is rated for 55A, correct? Also, if that's true, is it safe to go 5 higher or just something that can be done? I assume the wiring and breaker are rated to be safer than not...
 
  #52  
Old 07-22-16, 12:22 PM
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When the rating of the wire falls between two "standard" sized circuit breakers then the next higher rated CB may be used. Since standard circuit breakers are 50 and 60 ampere, 55 ampere being special, you may use a 60 ampere circuit breaker.
 
  #53  
Old 07-22-16, 01:08 PM
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This may help with your understanding also.

http://www.doityourself.com/forum/el...-diagrams.html
 
  #54  
Old 07-25-16, 07:26 AM
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Thanks! Those diagrams are very helpful.
 
 

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