Main panel rework (pictures)

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  #1  
Old 02-05-12, 09:45 PM
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Main panel rework (pictures)

I’d like to replace the panel shown in the pictures, for the reasons stated below. Can someone give me some advice? From my end the following questions, issues came to mimd:

1. How can this main panel be replaced?

2. Can I just replace the fuse busses and the breakers with contemporary ones, without getting into the messy and much bigger job of replacing the entire metal enclosure?

3. If I hire an electrician, does the electric company have to be involved? To me, the meter and main breaker seem integrated into the panel so if I bother replacing the whole thing isn’t it inevitable the electric Co would have to get involved?

4. There are two main fuses, 100A each, on each phase. Does this make the panel a 200A panel?

5. I want to replace the panel because I suspect some of the individual circuit overload breakers no longer work. Today, I tested it by loading a 3600W load (30A) on one of the 20A circuits for 10 seconds and it did not trip. I can find replacements for these legacy breakers but they are $38 each! vs. $3 for contemporary breakers. So I figured I might as well change the whole panel at this point.

6. The panel seems buried in the stucco…

7. I also read that these Zinsco panels are no longer reliable (or is it just the breakers that become faulty?) and most suggest replacing them.

Any advice greatly appreciated...



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  #2  
Old 02-05-12, 11:34 PM
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1. Just do it. It will entail cutting the stucco and then patching afterwards OR abandoning in place and installing new surface or recessed equipment. Assuming this is now located outdoors it may be possible to relocate to the opposite side of the wall.

2. No.

3. Yes, the electric company will need to disconnect the power from the original meter and reconnect to a new meter. You also need a permit from the local Authority Having Jurisdiction (town, city, county or state electrical inspector) which will also entail following specifications and having inspections. You may also be required to bring certain portions of the other wiring up to current standards.

4. No, this is a 100 ampere service.

5. Good thinking.

6. Yup, this will make replacement more difficult and probably require other trades to be involved for a finished job.

7. Zinsco panels have several deficiencies. The circuit breakers not tripping on overloads are just one of the deficiencies. The circuit breakers often become so corroded to the bus bars that removal is almost impossible without severe damage. The bus bars themselves have had failures.
 
  #3  
Old 02-06-12, 05:20 AM
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Since Furd covered all your questions, I will just add this. Breakers have what is called a trip curve. Based on the amount of overload and the time will change how fast a breaker trips. Just because the breaker says 20 amps does not mean that at 20.1 amps it immediately trips.
 
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Old 02-06-12, 09:58 AM
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Furd just takes all the fun out of it for the rest of us!
 
  #5  
Old 02-06-12, 05:17 PM
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I only have a few comments:

3) Around here we do not have to get the power company involved during the service change out. We just cut the overhead wires, change the panel and then reconnect them temporarily. After the inspector comes and checks the job (most cases the next day or so) he will then send the paperwork to the power company and they will put it on the schedule to connect it permanently.
If you hire an electrician, they will know what the proper procedures are to complete the change out.

4) This would be a perfect time to upgrade your service to 200 amps if that is something you wanted.

6) Nowadays panels are much larger (especially meter/panel combos) and would likely hide the old panel/stucco so there may not be anything to patch.
 
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Old 02-06-12, 05:31 PM
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3) Around here we do not have to get the power company involved during the service change out. We just cut the overhead wires, change the panel and then reconnect them temporarily. After the inspector comes and checks the job (most cases the next day or so) he will then send the paperwork to the power company and they will put it on the schedule to connect it permanently.
If you hire an electrician,
But this is not safe for a non electrician to attempt.
 
  #7  
Old 02-06-12, 05:57 PM
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What ThomasE could do is to install a new circuit breaker panel adjacent to the existing with a large conduit nipple or two between them. He could then pull the main fuses and run new wiring from the load side of the fuse block to the supply lugs of the new panel, remove the bus bars and circuit breakers from the old panel and use the old box as a junction box to splice new wires to reach the new circuit breakers.

He'd still have only a 100 ampere service and still have the fuses for the main cutout but at least it would get rid of the Zinsco circuit breakers.
 
  #8  
Old 02-06-12, 06:10 PM
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Thanks Furd for the good summary and all others for the advice.

I do like the piggyback panel option much better than the complete replacement. Otherwise the legacy breaker replacement option is starting to look mighty attractive.

The trio of Power-Company, Electrician, City-Authority will probably make the cost of such a project explode. I’m also afraid that the mere involvement of the city means that any DIY participation is out of the question (all the fun gone!). If the city catches whiff that I did anything myself on an electrical project, I’ll have all kinds of problems.

I'm not that excited about splicing all the wires, but installing a whole new panel would probably also involve splicing many of the existing load wires. Is there a really reliable way to splice wires in this case ?
 
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Old 02-06-12, 06:14 PM
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3) Around here we do not have to get the power company involved during the service change out. We just cut the overhead wires, change the panel and then reconnect them temporarily. After the inspector comes and checks the job (most cases the next day or so) he will then send the paperwork to the power company and they will put it on the schedule to connect it permanently.
If you hire an electrician, they will know what the proper procedures are to complete the change out.
That's exactly how it's done here too.
 
  #10  
Old 02-06-12, 06:20 PM
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Pcboss, thanks for reminding the energy dependence in breaker tripping. Perhaps I’m expecting too much from the breaker…

In retrospect, still seems that a 30A load (or perhaps it was something like 27A?, 3600W was nominal, but voltage may be less than 120V etc…) for 10 seconds should have done the breaker tripping. After all, power is proportional to the square of current, so raising the current to 150% should raise the power (heat) dissipated in the wire to 225%. Ok, for 10 sec only, perhaps it is still not in dangerous territory… but still I thought the breaker should react rather quickly, before temperature in wire and connections rise to dangerous levels … I was also thinking that a 12GA copper wire must not have that much thermal inertia and thus would reach terminal (i.e. dangerous in this case) equilibrium temperature pretty quickly…


But in any case, I’m digressing here. Perhaps I’m wrong, expecting too fast a response from the breaker (I guess that’s what happens when an electrical engineer starts tinkering with his wiring). There are probably simple practical specifications to breaker response which embody most of the relevant theory…
 
  #11  
Old 02-06-12, 06:24 PM
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I do like the piggyback panel option much better than the complete replacement. Otherwise the legacy breaker replacement option is starting to look mighty attractive.
Don't even think about breaker replacement; that Zinsco panel is very near the end of it's useful life. If you replace the breakers, there is a very good possibility you'll still have to do the job right with full replacement within just a few years. Why not do it right the first time and save a few bucks and avoid an emergency replacement later that might cost you substantially more than a scheduled replacement.
 
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Old 02-06-12, 07:02 PM
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For grins and giggles I found one trip curve that would hold 200% for almost 90 seconds.
 
  #13  
Old 02-06-12, 10:33 PM
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Indeed, if trip behavior for typical residential breakers is anything like what is shown here (pg2):

http://static.schneider-electric.us/...0600DB0105.pdf

…then I was way off in my expectations at tripping the breaker. The way I read it, at 150% of rated amps the (typical?) breaker takes anywhere between 70 and 400 seconds to trip!! And I was expecting 10 seconds would be enough !! :-)

But with such long delays, I’m apprehensive that it would be safe to test the breakers by overloading the actual residential circuits.

In any case, perhaps the breaker is still within spec, after all -- but I would still like to replace the Zinsco, or bypass it by adding an additional panel as one of the options implied by Furd.
 
  #14  
Old 02-07-12, 12:12 AM
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Back up and take some more pictures. Seeing the entire area may help one of us to provide more options.

Otherwise the legacy breaker replacement option is starting to look mighty attractive.
Zinsco circuit breakers have a nasty habit of corroding where they attach to the bus bars, you might find it near impossible to remove the breakers and even if you do you might find the bus bars corroded to the point that you cannot attach new breakers.
Is there a really reliable way to splice wires in this case ?
Yes. The higher cost (and quality) wire nuts with the "wings" are good. For such a job I personally would use Buchanan crimp caps with the four-way crimper and insulating caps. Downside is the cost of the crimper.

Amazon.com: Splice Cap Crimping Tool: Patio, Lawn & Garden

The steel crimps do not require the twisting of the wires as do the copper crimps. The four-way crimp makes a VERY secure splice.



One thing that is not an option is trying to avoid the permit and inspection.
 
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Old 02-07-12, 11:40 AM
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I would just bite the bullet and call in two or three electricians and get a price. They will handle the permit, materials, poco interaction, etc. All you need to do is write a check when it's all done (and maybe be home when the inspector stops by). It's actually quite easy for someone who's done it before.

I would certainly recommend a full replacement.
 
  #16  
Old 02-07-12, 12:50 PM
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Thanks for the clarification Ray! Yes, cutting the overhead wire should not be attempted by an untrained person!

On another side note, around here the power company does not charge (at least not us) to reconnect the overhead wires.

Furd's suggestion of mounting a new panel (which would be a sub panel) next to the old one is a good option. Then you only have to pull the main fuses to do the work of gutting the old panel and splicing in all the old circuits. (Which would be done using standard wirenuts.) However a permit will still be required.

I do agree that doing a full change out is the best option IMO.
 
  #17  
Old 02-07-12, 11:44 PM
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Here is another photo of the general area.



As you can see, there is no room on the right or left.

If I go with the creating a separate subpanel solution…the new subpanel could be added at the bottom -- with splicing of the existing load wires to reach the subpanel.

Now, I understand that splices inside the main panel are apparently ok. Is there any way to further protect the splices? (eg. enclosing them in further junction boxes, or having some sort of strap/clip/wire-guide to hold the wires neat and in place, so that if a splice were to come loose at some point, it would still tend to stay put in place and not wander and touch something else?
I mean, once the zinsco breakers and busses are gone, there will be lots of room in that box for wires and splices to move around.


And what about the neutral bar? I assume it would be ok to leave the Zinsco neutral bar as is.

BTW, I removed a few of the Zincso breakers and nothing was fused, the busses actually seem to be in ok shape.
 
  #18  
Old 02-08-12, 06:15 AM
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Twisting the copper wire before putting the wirenut will almost guarantee that the splice will not come undone. You can bundle the wires together with zip ties but IMO it is not necessary. Wires do not move much. The neutrals should originate the same location as the hots so they should be spliced to the new sub panel as well.
 
  #19  
Old 02-08-12, 11:15 AM
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As others have stated, the best idea is to completely redo the service entrance from the mast weatherhead all the way to a new main breaker panel. That is also the most expensive and least DIY friendly thing to do.

Installing a new panel under the existing is certainly an option but the power company's meter reader will see it is new equipment and he(she) MAY report it and then you could get into trouble for not having a permitted and inspected change. This is but one reason to do the permit and inspection.

As Tolyn stated, you want to run both the "hot" and neutrals to the new circuit breaker panel. You can use a "main lugs only" (MLO) panel rather than one with a main circuit breaker as the existing 100 ampere pull-out fuses will be the main overcurrent protection device (OCPD). There will be some question as to whether or not you need to separate equipment grounding conductors from the neutral bus. My opinion (which is worth every penny that you paid for it) is that you do NOT need such separation since the new panel is NOT a "sub-panel" but is indeed the service. Others may disagree strongly with this and state that you absolutely DO need to make that separation.


Tolyn is also correct that you really don't need to be concerned about the spliced wires moving around in the old panel. If this was an industrial situation the story would be different but... You would want to get a solid piece of sheet metal to install in place of the current cover or perhaps simply using POP rivets you could make a cover for the (now unused) circuit breaker openings.


You didn't state what was on the other side of the wall at this point. Installing a new panel inside may be an option.
 
  #20  
Old 02-09-12, 08:32 PM
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Thanks much. I’m just evaluating options at this point.

On the other side of the wall is the living room as you can see in this photo (left side wall). But a stud sensor, shows the presence of one stud in that space. So I DON'T think there is a full 14.5” bay in there.

 
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