# Thread: Single Strand Copper as Service Cable

1. ## Re: Single Strand Copper as Service Cable

Since the picture showed a single phase panel....three phase was not a consideration in my answer.

2. ## Re: Single Strand Copper as Service Cable

Originally Posted by Roger Frazee
Not enough information to answer the question as presented ... as we have already established.

I am not even going to try to figure out how this thread ended up the way it did.
And that's all that needed to be said Roger.

We know how this thread ended up the way it did.

3. ## Re: Single Strand Copper as Service Cable

Originally Posted by James Duffin
Since the picture showed a single phase panel....three phase was not a consideration in my answer.
Perhaps I should say the building service is 208Y120 3 phase with single phase metering.

Does that explain my point better and why there is a single phase panel in the condo unit? ... Only it is single phase 120/208 not 120/240.

The meter bank will get all three phases and each meter in the group of meters gets different pairs of phases. If a meter bank has 6 meters, 2 will have A and B, 2 will hve B and C, and 2 will be C and A phases. I hope that makes sense.

This way the phases are balanced and the condo units receive a normal single phase 3 wire with ground supply on the feeders to the units panelboard only the high voltage is 208 volts single phase not 240 volts single phase.

Table 310.15b6 will not apply in this situation

Last edited by Roger Frazee; 11-18-2010 at 06:41 PM.

4. ## Re: Single Strand Copper as Service Cable

That's a lot of assuming going on there to be based on the picture in the first post!

5. ## Re: Single Strand Copper as Service Cable

Originally Posted by James Duffin
That's a lot of assuming going on there to be based on the picture in the first post!
Maybe so .. but it is a 5 story condo ... anyway I'm moving on from this ... time to let it go.....

6. ## Re: Single Strand Copper as Service Cable

Ampacity: The current in amperes a conductor can carry continuously under the conditions of use without exceeding its temperature rating.

Determining allowable ampacity doesn't stop with James' citation when it comes to such a dwelling, in a 5th floor condo.

I'd say its safe to assume there are at least four other feeders in a 5-floor building (fair to say at least four other occupancies and a common area feed~!). Its more likely than not to be an elevator (at least 5 floors, assuming at least four of them are at or above grade). Reasonble to presume some riser/lifter pumps for water supply. Fair to reasonable assume some fire sprinkling or suppression system and exit lighting at least in common areas.

That's at least now how many other conductors in some common wireway, trough, tapped off, etc. It matters what is required (allowable ampacity) at the service disconnect to provide the 80 percent continuous without exceeding the allowable ampacity (i.e. temperature rating of the conductor(s), etc.

James' citation tells you the feeder from the disconnect doesn't have to exceed the allowable ampacity of what is brought Load side to the service disconnect. That doesn't mean there aren't possibly required adjustments for the allowable ampacity at that service disconnect. That citation does not exclude adjustments to the allowable ampacity due to number of conductors in a raceway, or load diversity of those shared raceway conductors for large multi-family occupancies, and does not apply to buildings which have other than 120/240 single-phase service.

Then we have to consider the path and what other current carrying conductors ride IN that path, and the character of those loads (diversity).

Is there a 4 awg solid copper conductor that may be used for this feeder to this equipment? No, I do not believe so.

Would 4awg stranded copper be sufficient for an allowable ampacity 100 amp feeder with a planned 80 amp continuous (3 hr. or more) design use, to the 5th floor condo? Perhaps, but more likely not, it depends. Is there any other form of occupancy in the building itself or load, other than purely residential and straight 120/240 single phase building service? If so you cannot use James' citation no matter what.

Are the pictured conductors sufficient for this eqiupment? No, I do not believe so, even if the ahead disconnect is a lesser ampacity (see closing paragraphs regarding wire size and the mains having been photographed and described.

Access may have to be arranged, but it must be available, just may not have been arranged or available at the timing of your "inspection", or perhaps was or would be refused to anything/anyone less than an electrician working under a bonded/insured electrical contractor, fully trained, qualified, and adorned with the correct PPE, safety tools, inspection equipment and training to do so. Access by qualified persons, perhaps in the company of the building engineer, maintenance, management, whatever, would/should be available to the qualified party who can be contracted to investigate this on behalf of the future purchaser, tenant, or present owner or occupant. There may be a fee related to reasonable costs/supervision/attendance involved in this access, that's a matter of state/local rules/laws, condo law, controlling documents, rules & regulations, etc.

125 A or less is also required to know if the mains CB for the panelboard and that which preceeds it is marked for 60, 60/75 or 75 C.

Armored conduit, no, doesn't exist. Armored cable, not for 100 amps allowable ampacity. Flexible metallic conduit - not more than six feet in total in the path load side.

Then one wonders the AGE of the building, size, the service equipment, etc. and vintage of condo/residential status, history of mixed occupancy, and if the pictured panelboard was a replacement to a pre-existing split bus...and if there is or was a delta breaker ahead.

Panelboards suitable for use as service equipment with the appropriate main terminal provisions can be used with reduced wire sizes indicated in Section 310.15(B)(6) and Table 310.15(B)(6) of the NEC if the wire connectors are also suitable for the reduced wire size.

So, in summary and conclusion:

If your real question is from what is pictured, is there a legitimate concern to call for a qualified electrical contractor/electrician to come in and evaluate the appropriateness of the equipment and supplying feeder thereto, based solely upon the first pictures you submitted and described the conditions, the answer is yes. A full evaluation needs to include access to the origin of this feeder and the disconnect line side. However by itself, as pictured and indicated, you're "covered" or justified making this referral, due to the listed/classified terminal/connector size (in relation to the feeder conductor size, or rather lack thereof). The language panel wiring diagram and labeling would be further supportive regarding use as other than service equipment.

The mains terminals connectors pictured and described are not suitable for the reduced wire size of the pictured conductors. I believe we have proven there to be a concensus that those pictured are too small to possibly be #4 AWG. IOW the connectors are too big for the conductors.

As I recall you indicated earlier it was indicated a #4 AWG to a 3/0 on the breaker, although the usual terminal lugs supplied and/or availble for this panel category (siemens/murray) for use with a 100 amp main CB would range #4 - 2/0 AWG (2/0 being the threshold for next level/increase for wire bending space),

Perhaps you've learned some things with this thread, one of which might be things to consider documenting having asked about, and disclaimer language, such as location of service disconnect, and accessibility, and arrangment or coordination of access to same, adding to the list of things such as utilites being on, etc. when coordinating inspections of such properties, and taking more and/or better pictures when encountering such concerns. Most, if not all, of the necessary "backup" and researchable detail information would be included in the panel labeling.

Last edited by H.G. Watson, Sr.; 11-18-2010 at 09:22 PM. Reason: dang formatting issues and replacing any words cap'd with underlining and/or bold and inserting a title above conclusionary paragraphs.

7. ## Re: Single Strand Copper as Service Cable

Been away for a year or so, I swear to God this is the first thread I picked to review. There's 15 minutes I can't get back.

The feeders look no larger than 8AWG, but as has been discussed, they may be fed from a 40 amp breaker.

I'm having flashbacks to crazy Al Austin the "engineer"

8. ## Re: Single Strand Copper as Service Cable

Been away for a year or so, I swear to God this is the first thread I picked to review. There's 15 minutes I can't get back...
You must be a speed reader.
Welcome back!

9. ## Re: Single Strand Copper as Service Cable

Originally Posted by H.G. Watson, Sr.
Panelboards suitable for use as service equipment with the appropriate main terminal provisions can be used with reduced wire sizes indicated in Section 310.15(B)(6) and Table 310.15(B)(6) of the NEC if the wire connectors are also suitable for the reduced wire size.

So, in summary and conclusion:

If your real question is from what is pictured, is there a legitimate concern to call for a qualified electrical contractor/electrician to come in and evaluate the appropriateness of the equipment and supplying feeder thereto, based solely upon the first pictures you submitted and described the conditions, the answer is yes. A full evaluation needs to include access to the origin of this feeder and the disconnect line side. However by itself, as pictured and indicated, you're "covered" or justified making this referral, due to the listed/classified terminal/connector size (in relation to the feeder conductor size, or rather lack thereof). The language panel wiring diagram and labeling would be further supportive regarding use as other than service equipment.

The mains terminals connectors pictured and described are not suitable for the reduced wire size of the pictured conductors. I believe we have proven there to be a concensus that those pictured are too small to possibly be #4 AWG. IOW the connectors are too big for the conductors.

As I recall you indicated earlier it was indicated a #4 AWG to a 3/0 on the breaker, although the usual terminal lugs supplied and/or availble for this panel category (siemens/murray) for use with a 100 amp main CB would range #4 - 2/0 AWG (2/0 being the threshold for next level/increase for wire bending space), Conductors smaller than #4 AWG are not allowed to be used in those terminals.

Perhaps you've learned some things with this thread, one of which might be things to consider documenting having asked about, and disclaimer language, such as location of service disconnect, and accessibility, and arrangment or coordination of access to same, adding to the list of things such as utilites being on, etc. when coordinating inspections of such properties, and taking more and/or better pictures when encountering such concerns. Most, if not all, of the necessary "backup" and researchable detail information would be included in the panel labeling.
Sometimes the obvious deficiency, defect, safety issue, violation, in and of ITSELF, the other questions MOOT - or irrelevant regards the HI. Pin down the ISSUE ITSELF - OBSERVE, REPORT and REFER to those QUALIFED.

This installation is OBVIOUSLY defective - regardless of what may be line side - the conductors pictured are too small for the lug terminals, they are NOT #4 AWG. It doesn't MATTER if there is lower OCPD/disconnect ahead of this installation - the safety/defect pictured is improper and a use outside of the listing/certification and has no field evaluation certification.

Get it? Got it? Good!

10. ## Re: Single Strand Copper as Service Cable

As I recall you indicated earlier it was indicated a #4 AWG to a 3/0 on the breaker, although the usual terminal lugs supplied and/or availble for this panel category (siemens/murray) for use with a 100 amp main CB would range #4 - 2/0 AWG (2/0 being the threshold for next level/increase for wire bending space), Conductors smaller than #4 AWG are not allowed to be used in those terminals.
Working in photoshop the main breaker in the posted picture is specified as

75C only cu/al AWG #4 - 3/0

So I agree no point in going any farther. The feeder conductors terminated are too small for the main breaker lug wire range.

11. ## Re: Single Strand Copper as Service Cable

Originally Posted by Roger Frazee
Working in photoshop the main breaker in the posted picture is specified as

75C cu/al only AWG #4 - 3/0

So I agree no point in going any farther. The feeder conductors terminated are too small for the lug wire range.
Yes, thank you for the 75C breaker info. As mentioned earlier that lug terminal kit is usually restricted to AWG #4 min. to 2/0 max.

"If you feed a hungry man a fish, you feed him for a day. If you teach a hungry man to fish, you feed him for a lifetime."

IOW, if you're asking the wrong questions, basing the questions on improper identifications, or asking an improper or irrelevant question; don't get upset if you don't immediately get "fed a fish" (or a piece of candy or garbage), i.e. get the answers you're demanding, but instead get clarification "questions" which are by design, to clarify your TRUE question - to either answer it correctly and immediately satiate; and/or when you fail to grasp the distinctions/nuances/errors; you are lead to a "fishing lesson".

Last edited by H.G. Watson, Sr.; 12-02-2010 at 09:17 AM.

To all,

13. ## Re: Single Strand Copper as Service Cable

My apologies Brian. I thought this thread was dead but somebody resurrected it and a couple people just can't can't seem to let things go. I reacted because I'm getting tired of the crap the same people keep dishing.

This board is unfortunately becoming very frustrating to use as a resource despite your efforts to straghten it out.

14. ## Re: Single Strand Copper as Service Cable

Originally Posted by Nick Ostrowski
Here you go HG. My only other pic of the panel. If you have something to offer, great.

Personally, I would never berate, admonish, or try to demean somebody who used improper terminology or may be off in an assessment. This type of behavior keeps other people lurking in the shadows and deters them from contributing.

Hmm... and you said that you had only one picture of the panel. Why didn't you post this in place of any of your other posts? It would have been helpful and less stressful on others. Also, was the panel label intact or missing? Could have found some info there.

Rich

15. ## Re: Single Strand Copper as Service Cable

Thiere several items that need to be looked at with this situation.
Most have been covered. ie close up og breaker states wire range, which if this is #8 would be wrong.
Did you try to read the writing on the cconductor?
single phase or 3 phase service. Loof at the service coming into the building, many times it can be determined if 1 phase or 3 phase.
anel

16. ## Re: Single Strand Copper as Service Cable

Originally Posted by Rich Goeken
Hmm... and you said that you had only one picture of the panel. Why didn't you post this in place of any of your other posts? It would have been helpful and less stressful on others. Also, was the panel label intact or missing? Could have found some info there.

Rich
I didn't post it because I knew it wasn't a great pic and I felt it was too far away to provide any detail. I fail to see how not posting that pic initially was a cause of stress for anybody.

There was no printing on the limited exposed sections of the conductors. They were inside armored conduit above their entry point into the panel.

We're going back about a month on this one. My recollection of any labels on the panel cover is foggy at best.

17. ## Re: Single Strand Copper as Service Cable

Originally Posted by Nick Ostrowski
I didn't post it because I knew it wasn't a great pic and I felt it was too far away to provide any detail. I fail to see how not posting that pic initially was a cause of stress for anybody.

There was no printing on the limited exposed sections of the conductors. They were inside armored conduit above their entry point into the panel.

We're going back about a month on this one. My recollection of any labels on the panel cover is foggy at best.
Armored conduit?!?

Please pick up on the distinctions with significance & difference.

Try Grounding vs Bonding - Part 8 of 12

Which will outline some of the differences between FMC, FMT, LFMC, AC, Type MC (and differences between Type MC "types").

Conduit is not cable, and vice versa.

In so far as bonding, Ampacity, limitations, and usage; and in the case of main power feeder these are critical distinctions for effective ground-fault current pathway, use limitations for allowable ampacity, etc., etc.!

Last edited by H.G. Watson, Sr.; 12-06-2010 at 09:59 AM.

18. ## Re: Single Strand Copper as Service Cable

This is what the conductors were in......armored conduit.

19. ## Re: Single Strand Copper as Service Cable

In the words of "Charlie Brown": Arghhhhhh!!! <insert moving jpeg of charlie brown rolling backwards>.

Note you have posted a photo which includes the emergence of a green insulated conductor amongst an identified (white insulated) conductor along with a black and red insulated conductor.

It is teeny tiny photo, and difficult to enlarge with its low resolution and see anything clearly; but does not appear interlocked, but corregated. However, is obviously a stock photo borrowed from somewhere, and not one of the installation.

P.S. If it comes/sold from the manufacturer with conductors therein, it is NOT conduit, therefore your borrowed "stock" photo has to be that of a cable assembly.

20. ## Re: Single Strand Copper as Service Cable

Originally Posted by H.G. Watson, Sr.
However, is obviously a stock photo borrowed from somewhere, and not one of the installation.
Congrats HG. You win the cupie doll.

21. ## Re: Single Strand Copper as Service Cable

Nick,

Apparently a glutton for punishment, I'm still endeavoring to be helpful.

I am challenged that after all which has been said and explained on this post, you continue to refer to something in this installation as "Armored Conduit".

Thank you for reconsidering and removing the post.

I'm going to link to and upload the specifications for southwire's "Armorlite (R)" Type MC Cable This Cable assembly has aluminum interlocked armor and is regularly available with up to size 2 AWG conductors.

Type MC Cable is addressed in NEC Art. 334.

Please note ampacities are limited as your circuit rating is 100A or less/to the the 60 degrees C column.

You'll see that even 4/3 & 4/4 are down to 70A at 60C applications (lowest common demoninator due to circuit rating equal to or less than 100A). Please pay attention to footnotes at the bottom of page 2 of 3.

You will also likely note that Southwire's Armorlite Type MC Cable is not available with larger than 10AWG SOLID conductors.

"Armor" is not conduit, it is a componant of a cable assembly.

Last edited by H.G. Watson, Sr.; 12-06-2010 at 11:25 AM.

22. ## Re: Single Strand Copper as Service Cable

OK, not trying to be a smartass here but can you please explain (in your words) as to when armored conduit is an applicable term and why my use of such term here is so egregious and the cause of such exasperation? The pic I posted above is just a quick cut and paste. I was not expecting insulation color on the conductors to be such an issue.

No links or attachments please. Just a straight concise explanation. If you can do that for me, I thank you in advance.

23. ## Re: Single Strand Copper as Service Cable

Nick,

A couple of pointers on terms here to help out:
- flexible metal conduit is the spiral wound conduit which is flexible and comes without conductors in it, this is what I think you are referring to when you say 'armored conduit'
- AC cable, which is armored cable, has the conductors manufactured in the cable, the flexible metal spiral wound covering provides the equipment ground path
- MC cable, which is metal clad cable, has the conductors manufactured in the cable, this looks similar to AC cable but has an insulated equipment ground conductor inside it

With flexible metal conduit the wires can be pulled out and replaced, and (sometimes) another wire or two may be able to be pulled in through the flexible metal conduit.

With AC or MC cable, the outer spiral wrap is wrapped around the conductors, there is no pulling them out or putting another in there.

However, this part of the discussion has digressed from your original question.

24. ## Re: Single Strand Copper as Service Cable

Thank you Jerry. Clear and concise.

25. ## Re: Single Strand Copper as Service Cable

Originally Posted by Nick Ostrowski
OK, not trying to be a smartass here but can you please explain (in your words) as to when armored conduit is an applicable term and why my use of such term here is so egregious and the cause of such exasperation? The pic I posted above is just a quick cut and paste. I was not expecting insulation color on the conductors to be such an issue.

No links or attachments please. Just a straight concise explanation. If you can do that for me, I thank you in advance.

Nick,

Jerry Peck, and before him Jim Port have already explained the difference between conductors and a cable assembly. Both times you've indicated you've understood and thanked them for their explanations.

Now, let us go back to the first few posts on this topic string.

I know you are aware, from prior discussion, as to, for example, the Ampacity limitations to for example, let us use NM cable, as I referenced early on. Although the actual conductors within the cable assembly (in this example we're referring to the more modern NM cable with THHN conductors, not older TW for example. The conductors themselves may have a higher temperature rating, but when using the overall cable assembly encased as it is in a sheath, we are further limited to using the 60C or in some cases the 75C temperature column in determining the overall (forgive the caps here they are for emphasis) ALLOWABLE AMPACITY for the overall cable assembly has to be within the temperature rating for the overall CABLE, NOT the individual conductors.

I know you understand the "weakest link in the chain" concept referring to an actual literal chain.

We apply the same regards to temperature limitations and ALLOWABLE ampacity regarding temperature limitations in electrical equipment.

I do hope I'm not being to wordy for you here and you are following along and haven't lost you yet...

When we discuss as in the instant case - the main power feeder to the condo - and address your question as to the allowable ampacity for the feeder - in this case we do NOT break down to componants of an ASSEMBLY. We have to consider the overall application of the assembly. The feeder conductors are not individual conductors pulled through a raceway (as you have referenced one of which might be "conduit") -- but an overall group of conductors which is a part of an overall assembly, namely CABLE, which that cable is further influenced by having been routed through possibly a trough, a raceway, etc. and is interconnected with other equipment. In this case we presume a lower ampere limiting OCPD line side, and as pictured a 100 amp OCPD at the condo.

If you go back and review the first few posts I made on this topic string you will find I made reference to the allowable ampacity being reduced due to a cable assembly employed, and not individual conductors pulled through raceway. I (and later Roger) also expanded on the distinctions and differences between other than 120/240 single phase BUILDING service. Just because an apparent THHN conductor as a componant of an Type MC cable is present - does not mean that you can consider it an individual THHN conductor - it is not. It is a componant of a cable assembly - if that is the case, and it is treated (and its allowable amacity is) different.

individual conductors pulled through conduit is significantly different than conductors as a part of a cable, which is also significantly different than cables through a common raceway.

Identifying conduit with a cable nomenclature is apples and oranges; and vice versa.

What flies as a conductor at 75 or 90 C does not when it is encorporated as a componant of a cable assembly which must not be applied above 60C in its pictured application.

this is due to (partially) lack of space/air within the cable assembly for the metal "conductors" to put-off the heat, the insulation around the indivual conductors, and the overall teflon/thermoplastic/poly jacket which surrounds the conductors which insulates, reflects and prevents the off-puting of the heat.

Its kind of like the difference between "Rocky" running the streets of Philly in a 100% cotton fleece "jogging" outfit and doing the same wrapped in saran wrap and polyester fleece. If you're wearing a plastic, fleece lined sweat suit you're body core temperature will rise because whatever is covered can't efficiently "put-off" the heat to the air, and Rocky would ll be swimming in sweat under all that plastic and VERY HOT (and likely lost a few MORE pounds of sweat then if he ran the route in just a regular 100% cotton fleece jogging outfit - as some of that sweat would have evaporated along the way serving to cool him, and his core temperature would have been better regulated and not so likely to have gone overboard an caused a heat stroke!).

Metal jackets to free air conduct HEAT. Thermoplastic tends to not only insulate conductivity of electricity but also insulate/prevent ready transfer of HEAT to the air surrounding it.

Does that make some sense?

As usual, I likely failed to keep it simple enough, and likely wandered too far and lost you yet again.

I'll try to sum up with a simple statement. Cable assemblies are distinctly different then individual conductors pulled through conduit or other raceway. It is important to know the difference - it is not just pure semantics, their applications are unique, especially when it comes to allowable ampacity in various installation situations, such as the not so simple 5th floor condo main power feeder and occupancy accessible mains and distribution panel.

There is no conduit which is "armored" the words do not belong together ("armored conduit" = does not compute!).

"armored cable" or type AC is limited in ampacity applications. Apparently you have "Type MC Cable". Cable is determined and limited in temperature applications overall as an assembly - we do not identify it by its individual componants. Type MC can get further confusing. We can have steel or aluminum, we can have interlocked, corregated or tube.

Last edited by H.G. Watson, Sr.; 12-06-2010 at 09:08 PM.

26. ## Re: Single Strand Copper as Service Cable

Good info HG.....but.......I was hoping for concise. We're performing home inspections here. We're not professional electricians. We are generalists. We're not breaking down the intricacies of an installation and giving our clients a tutorial on electrical terminology. We inspect and defer as needed.

27. ## Re: Single Strand Copper as Service Cable

Originally Posted by Nick Ostrowski
Good info HG.....but.......I was hoping for concise. We're performing home inspections here. We're not professional electricians. We are generalists. We're not breaking down the intricacies of an installation and giving our clients a tutorial on electrical terminology. We inspect and defer as needed.
Nick!

It was you who posed the question and created the topic string, and directed the question to be one of case for solid 4 AWG conductors, and posed what was sufficient to provide an allowable ampacity of 100 Amp supply to this condo panel. You called it a "service" and called a cable assembly component "conduit".

If you're happy calling a "toilet" a "turd-let" so be it. I don't know whether to laugh or cry at you or with you.

28. ## Re: Single Strand Copper as Service Cable

If it says anything as to if it is right or wrong or got rewired at a later date.....The panel certainly does not look like the original as the wires in it have over spray on them and the inside of that new panel does not.

I think a lot may have been changed around from the original over time.

29. ## Re: Single Strand Copper as Service Cable

Originally Posted by H.G. Watson, Sr.
Nick!

It was you who posed the question and created the topic string, and directed the question to be one of case for solid 4 AWG conductors, and posed what was sufficient to provide an allowable ampacity of 100 Amp supply to this condo panel. You called it a "service" and called a cable assembly component "conduit".

If you're happy calling a "toilet" a "turd-let" so be it. I don't know whether to laugh or cry at you or with you.
I feel the same about you bud. A simple question turns in a 90+ post diatribe where verbiage is sliced and diced and disected and bisected when my original question really was not that complicated. I hung in and continued to ask for feedback because I wanted to see what was so uproarious and egregious about my post, question, and terminology. The only person who seems to find all this so appalling is you.

Please bury this and move on.

Last edited by Nick Ostrowski; 12-07-2010 at 07:49 AM.

30. ## Re: Single Strand Copper as Service Cable

Here is the original question from Nick:

"If single stranded copper could be used as the main feed to a 100 amp panel, what would the minimum required gauge size?"

The answer is #4 as I said in post #3. Pretty simple question and answer it seems.

31. ## Re: Single Strand Copper as Service Cable

Originally Posted by Jerry Peck
Nick,

A couple of pointers on terms here to help out:
- flexible metal conduit is the spiral wound conduit which is flexible and comes without conductors in it, this is what I think you are referring to when you say 'armored conduit'
- AC cable, which is armored cable, has the conductors manufactured in the cable, the flexible metal spiral wound covering provides the equipment ground path
- MC cable, which is metal clad cable, has the conductors manufactured in the cable, this looks similar to AC cable but has an insulated equipment ground conductor inside it

With flexible metal conduit the wires can be pulled out and replaced, and (sometimes) another wire or two may be able to be pulled in through the flexible metal conduit.

With AC or MC cable, the outer spiral wrap is wrapped around the conductors, there is no pulling them out or putting another in there.

However, this part of the discussion has digressed from your original question.
Jerry
Very good post concise and to the point. Not wordy nor is it putting someone down. Hope to see more posts like this one. I understood what Nick was saying. He may not have had the nomenclature correct. But he did know that the wires were in a metal flexible conduit. I think your post was helpful to Nick and others on here.
Thank You

32. ## Re: Single Strand Copper as Service Cable

Originally Posted by James Duffin
Here is the original question from Nick:

"If single stranded copper could be used as the main feed to a 100 amp panel, what would the minimum required gauge size?"

The answer is #4 as I said in post #3. Pretty simple question and answer it seems.
Nope. That answer is WRONG, it is concisely and completely WRONG for the panel as installed, where installed, pictured and described by the OP.

If solid copper conductor cable assembly is used as the feeder, the maximum size permitted is #10 AWG. This, of course would not provide a 100A rated feeder, but a much lower allowable ampacity.

The conductors for the cable assembly would have to be stranded if equal to or in excess of size 8 AWG.

The mains OCPD in the pictured panel requires minimum #4 AWG Cu Conductor(s) for its connection point(s). The mains OCPD pictured requires a properly rated 75C supply. The terminal lugs pictured are not listed/classified to be used for anything less than a single #4 AWG Copper termination.

Armor means cable. Cables are armored, conduit is not "armored".

The section Mr. Duffin relies upon is not applicable to the installation (5th floor condo).

33. ## Re: Single Strand Copper as Service Cable

Originally Posted by Nick Ostrowski
I just looked at a zoomed shot of the breaker and the stamped specs from the manufacturer say it is rated for CU/AL AWG #4-3/0.

Assuming I'm interpreting this correction, as long as this feeder cable is a 4 gauge, it may be alright. Is this correct?
No, your assumptions are not correct since you are again basing the question upon a feeder (main power feeder circuit though it may be) to be RATED at allowable ampacity of 100A.

For a LOWER circuit (feeder circuit, main power feeder circuit) allowable ampacity, perhaps, but no where near 100A.

The "weakest link" in the chain.

NEC 110.14(C), a pesky little rule regarding temperature ratings and circuits equal to or less than 100A that showed up about circa 1993.

Without evidence to the contrary, we must presume the OCPD protecting the feeder, the equipment ratings, and therefore the feeder circuit itself is limited to rating its allowable ampacity at 60 degrees C; however due to the equipment in the Condo, we must ASSURE that it is 75C insulated and permitted use.

We further have no information on bundling, pathways, distance, ambient temperatures, etc.

I've never heard anyone ever complain that Charlie Trout was ever less than concise or that he was ever verbose.

Try: Electrical Contractor: Blast from the Past

Next I'll borrow a bit from a technical bulletin from a respected manufacturer:

Caution on using lug ratings: When terminations are inside equipment such as panelboards, motor control centers, switchboards, enclosed circuit breakers, safety switches, etc., follow the temperature rating identified on the equipment labeling instead of the rating of the lug itself. Manufacturers commonly use 90C-rated lugs (il.e., marked AL9CU) on equipment rated only 60C or 75C. The use of the 90C-rated lug in this type of equipment does not allow the installer to use 90C wire at the 90C ampacity. The Underwriters Laboratories General Information on Electrical Equipment Directory states the following about terminations: "A 75C or 90C temperature marking on a terminal (e.g. AL7, CU7AL, AL7CU or AL9, CU9AL, AL9CU) does not in itself indicate that a 75C or 90C insulated wire can be used unless the equipment in which the terminals are installed is marked for 75C or 90C".

Review the labeling of ALL devices and EQUIPMENT for installation guidelines and possible restrictions.

Available Equipment Terminations:

Remember that a conductor has TWO ENDS, and that the termination on EACH END must be considered when applying the sizing rules. For example, consider a conductor wired to a 75C termination on a circuit breaker at one end, and a 60C termination on a receptacle at the other end. This circuit must be wired with a conductor that has an insulation rating of at least 75C (due to the circuit breaker) and SIZED based on the AMPACITY OF 60-degrees C (due to the receptacle).
In conclusion, Garbage in-garbage out.

Last edited by H.G. Watson, Sr.; 12-07-2010 at 11:49 AM.

34. ## Re: Single Strand Copper as Service Cable

I stumbled upon this thread today. It looks to me that from the beginning HG was more concerned with letting Nick know how much more he knows than actually trying to give some direction.

35. ## Re: Single Strand Copper as Service Cable

Originally Posted by ray jackson
I stumbled upon this thread today. It looks to me that from the beginning HG was more concerned with letting Nick know how much more he knows than actually trying to give some direction.

Thank you Ray. I feel the same way. He seems to do that quite often

36. ## Re: Single Strand Copper as Service Cable

Let's see if we can clear this up and put an end to this thread within 100 posts, ... and we are almost there!

Originally Posted by Nick Ostrowski
I looked at a condo unit yesterday that had a 100 amp main disconnect in the panel. The cable feeding the box and attached to the 100 amp disconnect was a single strand copper cable that looked to be no better than 4 gauge but I couldn't be sure. The cable above the box before entering it was enclosed in armored conduit. It appears undersized to be me for a 100 amp disconnect.

If single stranded copper could be used as the main feed to a 100 amp panel, what would the minimum required gauge size?
James replied:
Originally Posted by James Duffin
If you are sure it is #4 you should be ok. #4 is rated at 100 amps for a service.
James restated:
Originally Posted by James Duffin
Here is the original question from Nick:

"If single stranded copper could be used as the main feed to a 100 amp panel, what would the minimum required gauge size?"

The answer is #4 as I said in post #3. Pretty simple question and answer it seems.
I'll go through Nick's original post in sections, highlighting what is important and why James was, and is, correct.

"I looked at a condo unit yesterday ... "

Nick inspected a CONDO, and that means that it is HIGHLY UNLIKELY that there is but one panel in the condo (yes, I have inspected many condos which had two or three panels, but those were 7,000 to 10,000 sf condos, not what I think Nick inspected).

I.e., that panel is serving *all* the loads of the dwelling unit.

" ... that had a 100 amp main disconnect in the panel. The cable feeding the box and attached to the 100 amp disconnect was a single strand copper cable that looked to be no better than 4 gauge but I couldn't be sure."

Okay, a 100 amp overcurrent device can be fed with #4 AWG copper and be code compliant *as long as* "For application of this section, the main power feeder shall be the feeder between the main disconnect and the panelboard that supplies, either by branch circuits or by feeders, or both, all loads that are part or associated with the dwelling unit." - which I believe that panel meets.

Now, the NEC says this about the use of stranded conductors:
- 310.3 Stranded Conductors.
- - Where installed in raceways, conductors of size 8 AWG and larger shall be stranded.
- - - Exception: As permitted or required elsewhere in this Code.

"The cable above the box before entering it was enclosed in armored conduit. It appears undersized to be me for a 100 amp disconnect."

Nick tells us in the above that "the cable" (i.e., no raceway) ... therefore the conductors 'may be' solid and are not required to be stranded.

"If single stranded copper could be used as the main feed to a 100 amp panel, what would the minimum required gauge size?"

The NEC says, with the qualification I noted above for the panel serving *all* the loads of the dwelling unit, that #4 copper may be used for that 100 amp disconnect.

DANG! While I was typing someone posted post #100, making mine #101.

37. ## Re: Single Strand Copper as Service Cable

Originally Posted by Jerry Peck
Let's see if we can clear this up and put an end to this thread within 100 posts, ... and we are almost there!

James replied:

James restated:

I'll go through Nick's original post in sections, highlighting what is important and why James was, and is, correct.

"I looked at a condo unit yesterday ... "

Nick inspected a CONDO, and that means that it is HIGHLY UNLIKELY that there is but one panel in the condo (yes, I have inspected many condos which had two or three panels, but those were 7,000 to 10,000 sf condos, not what I think Nick inspected).

I.e., that panel is serving *all* the loads of the dwelling unit.

" ... that had a 100 amp main disconnect in the panel. The cable feeding the box and attached to the 100 amp disconnect was a single strand copper cable that looked to be no better than 4 gauge but I couldn't be sure."

Okay, a 100 amp overcurrent device can be fed with #4 AWG copper and be code compliant *as long as* "For application of this section, the main power feeder shall be the feeder between the main disconnect and the panelboard that supplies, either by branch circuits or by feeders, or both, all loads that are part or associated with the dwelling unit." - which I believe that panel meets.

Now, the NEC says this about the use of stranded conductors:
- 310.3 Stranded Conductors.
- - Where installed in raceways, conductors of size 8 AWG and larger shall be stranded.
- - - Exception: As permitted or required elsewhere in this Code.

"The cable above the box before entering it was enclosed in armored conduit. It appears undersized to be me for a 100 amp disconnect."

Nick tells us in the above that "the cable" (i.e., no raceway) ... therefore the conductors 'may be' solid and are not required to be stranded.

"If single stranded copper could be used as the main feed to a 100 amp panel, what would the minimum required gauge size?"

The NEC says, with the qualification I noted above for the panel serving *all* the loads of the dwelling unit, that #4 copper may be used for that 100 amp disconnect.

DANG! While I was typing someone posted post #100, making mine #101.
Well Jerry Peck you've managed to both contradict the NEC and yourself multiple times in that summary and conclusion statement post.

Conduit is one of many types of raceway. Either there is or is not a raceway somewhere, anywhere between the origination and termination. If you're going to accept an oxymoron "armored conduit" and keep using the word conduit then conduit is a RACEWAY. Cable can be in conduit or another raceway, but there is no such thing as "armored conduit". Neither you nor Nick has any idea what the conductors are in from the meter to this panel, if cables are stacked, in close proximity for 24" or more, the ambient temperature where they run (next to steam pipes for all we know), whatever.

Next, the section you and Mr. Duffin before you attempt to employ does not fit the circumstances of a 5th floor condo. Next, if you refer to the conductors permitted in that section you'll be hard-pressed to find a 4AWG solid conductor amongst them.

Next you have a 100 A or lower ampacity OCPD line side of this feeder, which has not been visualized or identified as being anything other than 60 degrees C, and without any proof to the contrary it MUST be presumed to be 60C.

Good luck finding a 75C insulated 4AWG SOLID not STRANDED CU conductor named in the section you rely upon that provides 100 A allowable ampacity at 60C.

However, its all moot as the POCO service to the BUILDING for a five(plus) story condo building wouldn't be 120/240 split single phase, so you still can't use the section you both rely upon.

That electrical room or area with the occupancy meters and common area meters which was off limits to Nick at the time of the inspection, supposedly not located in an accessible common area, is likely under restricted management/maintenance/supervision. Why would that be? hmmmm. Raceway/wireway bonding perhaps amongst may other likely considerations.

38. ## Re: Single Strand Copper as Service Cable

Shall we play Sesame Street's "One of these things is not like the other" between the two photos, and consider the "no access" to the line side of the panel ? Or discuss what is and is not seen on the left and right sides of the panel in the second picture ?

39. ## Re: Single Strand Copper as Service Cable

Jerry
Very good post concise and to the point. Not wordy nor is it putting someone down. Hope to see more posts like this one. I understood what Nick was saying. He may not have had the nomenclature correct. But he did know that the wires were in a metal flexible conduit. I think your post was helpful to Nick and others on here.
Thank You

Interesting...

There seems to be some disagreement on what was or was not present - as the poster you're complimenting (Jerry Peck) - has taken a position that there was NO RACEWAY (conduit or otherwise) present at all, including flex.

Also interesting that the OP has posted a stock photo of a cable assembly, apparently type MC and calls this "armored conduit".

40. ## Re: Single Strand Copper as Service Cable

Anyone else wondering what Watson is smoking?

41. ## Re: Single Strand Copper as Service Cable

Originally Posted by Jerry Peck
Anyone else wondering what Watson is smoking?
ME ... SMOKING? What am I smoking?

Look Mr. Peck: You explain to ME how you're going to even begin to apply a section {310.15(B)(6) and Table 310.15(B)(6)} which doesn't apply to a 5th floor condo, and Explain how you are going to get those Art. 310 conductor wires comprising that feeder up to that 5th floor condo panel without using a raceway?

And explain it to me how you are going to get a feeder set comprised of one of eleven types of wires/conductors (Art. 310) {five types of Thermoset insulated individual conductors/wires or one of six types of Thermoplastic insulated individual conductors/wires } up to that 5th floor condo panel without using a raceway or similar. Or are you saying that SE, USE, or USE-2 Service Cable (Art. 338) is available in an "armored" version?

Otherwise get off 310.15(B)(6)and get back to where this belongs.

Then you tell ME what the heck "armored conduit" is supposed to be!!! It sure ain't "Type MV Type MC"!

Dare we get into raceways that are not technically "conduit"?

You're the one that stated up at post 101 above that there was NO RACEWAY, right after claiming it was a CABLE. Hmmm. An Armored Cable apparently.

Show me SE, or USE, with armor please, then show me one with #4 AWG solid CU condutors, and then please show me that armored SE or USE with solid Copper #4 AWG with 100A allowable ampacity at 60C.

42. ## Re: Single Strand Copper as Service Cable

Since there is OCPD of an unknown size ahead of this panel the 100 amp breaker could just be acting as a local disconnect if properly sized to the conductor. As such there would be no need the 100 amp breaker to match the conductor ampacity. It would just a a convenience for the occupant.

This would not relieve the other issues like the size range on the lug.

How was it determined from a picture of part of a panel that this feeder did not serve the entire load and that 310.15(B)(6) could not be used? How do we know the voltage is not 120/240 1P?

43. ## Re: Single Strand Copper as Service Cable

Originally Posted by Jim Port
Since there is OCPD of an unknown size ahead of this panel the 100 amp breaker could just be acting as a local disconnect if properly sized to the conductor. As such there would be no need the 100 amp breaker to match the conductor ampacity. It would just a a convenience for the occupant.

This would not relieve the other issues like the size range on the lug.

How was it determined from a picture of part of a panel that this feeder did not serve the entire load and that 310.15(B)(6) could not be used? How do we know the voltage is not 120/240 1P?
That wasn't the OP's "corrected" question. Apparently you missed the second post.

His question was regarding a sufficient feeder to provide 100 A to this panel - and then he continued with it being done with solid CU conductors.

The OP, who has most recently posted a stock photo of a Cable assembly with armor - has from the beginning referred to the feeder as Cable. There are only three cables referenced in 310.15(B)(6), and they are all service cable.

Yes, I know Mr. Peck recently opined that the OP meant FMC with conductors therein, as to his "armored conduit" statement. He then went on however in his summary re-buttressing Mr. Duffin that the feeder was a cable and that the feeder was in NO WAY contained in a raceway (which negates the possibility then of FMC now doesn't it?). Of course for FMC "Armored Conduit" to be used there would have to be an insulated EGC.

The service to the BUILDING has to be other than 120/240 service. There are at least five floors of occupied space.

It has already been covered, and you are overlooking Chapter 1 and what is missing and present in the poor quality overall panel picture.

I guess for clarity, I should say that it seemed to me quite apparent with all the OP has said regarding his limited access within the building - that the feeder originates inside the condo building.

Last edited by H.G. Watson, Sr.; 12-08-2010 at 10:09 PM.

44. ## Re: Single Strand Copper as Service Cable

I'm curious ... is it just me or do others also see that H. G. appears to have slipped back into his less-than-helpful and holier-than-thou stance from his high horse the last few weeks?

45. ## Re: Single Strand Copper as Service Cable

Originally Posted by Jerry Peck
I'm curious ... is it just me or do others also see that H. G. appears to have slipped back into his less-than-helpful and holier-than-thou stance from his high horse the last few weeks?

I do not think he has ever gotten out of it. To bad he can not use his knowledge to be helpful instead of seeing how much he can put someone down. And make himself look so small.

46. ## Re: Single Strand Copper as Service Cable

Here's what seems obvious to me... a lot of you guys are plain crazy.

So what if Nick's question had improper terminology. There's the "helpful" way of both correcting the terminology and answering his questions, and then there's the "denigrating" way. There's actually two questions there: can single stranded (solid) wire be used for a 100A feeder and if so, what is the minimum size it would need to be? Here's what I would consider a more "helpful" way of addressing his questions.

Originally Posted by Nick Ostrowski
I looked at a condo unit yesterday that had a 100 amp main disconnect in the panel. The cable feeding the box and attached to the 100 amp disconnect was a single strand copper cable that looked to be no better than 4 gauge but I couldn't be sure. The cable above the box before entering it was enclosed in armored conduit. It appears undersized to be me for a 100 amp disconnect.

If single stranded copper could be used as the main feed to a 100 amp panel, what would the minimum required gauge size?
The minimum size for a solid conductor used as a feeder for a 100A distribution panel is 4awg, however it can only be used under certain circumstances. Regardless of whether this installation fits those circumstances (doesn't appear to based on the limited information you've given), looking at your picture those conductors appear to be smaller than 4awg - probably 8awg which has a limit of 50A at best (40A typical) in your situation.

Now it's entirely possible (but not likely) that the distribution panel upstream of this unit has an over-current protection device limiting the feeder to 50A. If the panel was replaced, it may have had a stock 100A disconnect that wasn't sized for the feeder. Even if this was the case, however, the terminals in the distribution panel pictured have a minimum conductor size of 4awg, which disqualifies this feeder.

The feeder itself is very unlikely to be an armored cable; more likely the conductors are pulled through some type of flexible conduit which has a similar appearance to armored cable (AC) or metal clad cable (MC). Common AC and MC cables use solid conductors for 14awg through 10awg, 7-strand for 8awg through 2awg, 19-strand for 1awg through 4/0, and 37-strand for 250 through 500 kcmil. There are some industrial armored cables with 8awg solid but they're usually more expensive (read: less profit for electrician) and not found in residential settings.

Would that have been so hard to do?

47. ## Re: Single Strand Copper as Service Cable

Originally Posted by Jerry Peck
I'm curious ... is it just me or do others also see that H. G. appears to have slipped back into his less-than-helpful and holier-than-thou stance from his high horse the last few weeks?
jp,
yup, he has been on the ignore list for a long time now. what ever happened to elliot franson? he was as much fun as aaron miller!

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