Build Your own PV Combiner

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iwire said:
You will not get any argument from me on that. But in this area many jobs can only be bid by companies with NABCEP certification.
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I can reasonably understand why.
Not going to get into it here. the thread would get deleted.
This is part of the issue.

Not much really other than 60 hours of Monday nights at the local Community Collage and paying $85 to take a test. All it really means is the company I work for will be able to bid more jobs.
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Seriously, nowhere in the course did they discuss 'Acceptable Wire Splicing Methods'?

BTW, it means more than that.
 
rickgomes26 said:
With regard to 05' and this situation, while we don't have the language that the 08' has, we DO have article 90.4, "Enforcement....The Authority having jurisdisction for enforcement of the CODE has the responsibiliity for making interpretations of the rules, for deciding on the APPROVAL OF EQUIPMENT and materials, and for granting special permissions...."

That said, I have no problem in requiring NRTL certification for field built equipment.
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I question you using 90.4

The 'Authority...' is the body that has accepted the NEC into Law, not the inspector.
 
I accept your question. However the Inspector is the AHJ with the authority given them by the Building Official of that Jurisdiction. The Building Official will have the ultimate say in determining whether or not an Inspector's interpretation is accurate. In this particular case its easy to get the backing of the BO to use 90.4 as 08' addresses this equipment issue specifically.

Article 100 - Authority Having Jurisdiction - The organization, office, or INDIVIDUAL RESPONSIBLE for approving equipment, materials, an installation or procedure.

The INSPECTOR is the Individual approving equipment that is part of an installation.
 
rickgomes26 said:
... I have no problem in requiring NRTL certification for field built equipment.
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augie47 said:
Wise choice, IMHO.
As strict as California is, I'm surprised they don't have a State law (as does TN) requiring NRTL or even a California Standard.
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Okay wizzards with the wise choices:roll:: Does this apply to only source combiners or all electrical equipment? The way you two are talking this would apply to all.

What is your plan for all of the electrical stuff that doesn't have a Nrtl listing to go by? Yes, if one does other than house wiring there is a lot of equipment that does not have a listing. Some of us do buy equipment that is not sold at Blue or Orange or Wal-mart.

Do you both say that Art 409 is not valid? Does all equipment build under art 409 require a field Nrtl evaluation? That nrtl field evaluation can easily be multi-thousands.

IMO it's a poor choice. 110.3 is in the NEC for a reason. I believe AHJs can hire examiners smart enough to use it.

cf
 
Cold Fusion said:
Okay wizzards with the wise choices:roll:: Does this apply to only source combiners or all electrical equipment?
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The code section I posted applies specifically to a list of PV related equipment, combiners being in the list.

I don't like it but it says what it says.




The way you two are talking this would apply to all.
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The AHJ has (in most areas) the right not to approve equipment, (See 90.4) There is nothing in the NEC that says an AHJ must accept listed equipment. Here in MA t90.4 has been amended to require the AHJ to accept listed equipment used per listing.


Yes, if one does other than house wiring there is a lot of equipment that does not have a listing.
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The AHJ in most case is not required to approve it.
 
augie47 said:
Wise choice, IMHO.
As strict as California is, I'm surprised they don't have a State law (as does TN) requiring NRTL or even a California Standard.
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I dont know about the state, but many local jurisdictions (Los Angeles is one) have UL or approved NRTL listing requirements in their municipal codes.
 
Cold Fusion said:
Okay wizzards with the wise choices:roll:: Does this apply to only source combiners or all electrical equipment? The way you two are talking this would apply to all.

What is your plan for all of the electrical stuff that doesn't have a Nrtl listing to go by? Yes, if one does other than house wiring there is a lot of equipment that does not have a listing. Some of us do buy equipment that is not sold at Blue or Orange or Wal-mart.

Do you both say that Art 409 is not valid? Does all equipment build under art 409 require a field Nrtl evaluation? That nrtl field evaluation can easily be multi-thousands.

IMO it's a poor choice. 110.3 is in the NEC for a reason. I believe AHJs can hire examiners smart enough to use it.

cf
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In TN, it applies to all electrical equipment. See Post #16.
As with most things, how strictly it's enforced may vary from area to area.
In my experience, if a E/C purchases a couple of NRTL listed motor starters and mounts them in a cabinet using NEC wiring methods, the local EI will probably accept it without an "assembly" NRTL.
Once you vary from NEC in building an assembly, such as most Art 409 equipment, a NRTL listing is almost always required.
 
Cold Fusion said:
Okay wizzards with the wise choices:roll:: Does this apply to only source combiners or all electrical equipment? The way you two are talking this would apply to all.

cf
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For purposes of this discussion I'm limiting my comments to PV source combiners. I'm comfortable with that because we all know that the 2008 gets very specific about it with 690.4 (D).
 
ty said:
As the voltage is lowered, the amperage goes up.
So a 190watt at 60v is going to be less amps than 190watts at 30volts.

any and all training courses that I have taken call out wirenuts as unacceptable splicing for PV systems.
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Well i do not install solar systems and please dont take this the wrong way TY but DC or AC current takes the path of least resistance who ever is teaching that a scotchlock or wire nut is not acceptable is wrong .

The flow of current is going to flow in and thur the conductors not via the tap or metal around the mechanical connection in a wire nut.

The wire nut is just a method of attachment a lug on the other hand can be a current carrier and that depends on application or connection of use or how is mechanically connected .

Unless they are just saying that a better connection would be a mechanical lug meaning like a pressure type set screw lug then a wire nut do to expansion or contraction of metal of a wire nut that may come loose if the load current changes up or down and then i can see what they are saying would be correct but i have to say iwire is correct in his statement all wire nuts made today are listed for any current temp on that size wire in fact there rated for more than what is going to be used and at rated voltage they have to have a ul listing .

But in a control box or a termination box i think it looks much better with out scotchlocks or wire nuts so i would not use them .
 
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ohmhead said:
Well i do not install solar systems and please dont take this the wrong way
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I don't
DC or AC current takes the path of least resistance
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myth
who ever is teaching that a scotchlock or wire nut is not acceptable is wrong
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I never said it was not acceptable, i said it is not recommended.
I agree with them.
a better connection would be a mechanical lug meaning like a pressure type set screw lug then a wire nut do to expansion or contraction of metal of a wire nut that may come loose if the load current changes up or down and then i can see what they are saying would be correct
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Maybe that's it.
Poor connections add circuit resistance, increasing voltage drop, and power loss.
But in a control box or a termination box i think it looks much better with out scotchlocks or wire nuts so i would not use them .
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The whole point is the OP is questioning a combiner box.
This particular one wasn't even made in the field.
He is questioning it.
I asked for a photo and haven't seen one (of the combiner box in question)so it is hard to give an accurate opinion.
So we can only give one based on Code, which in 2008NEC there was a change.
My opinion was: If the fill size is correct, and it has rated terminal blocks, etc, etc, what's the real issue?
If it is a bowl of spaghetti, and looks like the installer didn't care, then different opinion.
 
ty said:
I don't

myth

I never said it was not acceptable, i said it is not recommended.
I agree with them.

Maybe that's it.
Poor connections add circuit resistance, increasing voltage drop, and power loss.

The whole point is the OP is questioning a combiner box.
This particular one wasn't even made in the field.
He is questioning it.
I asked for a photo and haven't seen one (of the combiner box in question)so it is hard to give an accurate opinion.
So we can only give one based on Code, which in 2008NEC there was a change.
My opinion was: If the fill size is correct, and it has rated terminal blocks, etc, etc, what's the real issue?
If it is a bowl of spaghetti, and looks like the installer didn't care, then different opinion.
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Well i agree with everything but the myth please explain iam willing to listen to your theory ?
 
Cold Fusion said:
I'm not too familiar with PV installations. What is in a "combiner box"? Is it just a bunch of terminals and DIN rail mounted fuse holders?

cf
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A bit late, it took me a while to find the disc this was on.

This is a brand we use, I think we could do it better, this is expensive for what it is but it is listed as a whole.

CombinerBox.jpg
 
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