We are about to upgrade our panel from 100A to 200A.
The run from the electric company drop to the panel is about 15 ft
vertical drop followed by 30 feet horizontal run within the house.
- Other than the fact that copper costs much more than aluminum, what
are the pros/cons of copper vs. aluminum?
- Is copper worth the added cost?
- Also, the supply will run through the unfinished utility portion of
the basement at joist level. Is it worth it to encase the cable in
metal (or pvc) conduit?
Running a service wire that far inside the building means it
must be in conduit. You have no choice. More important
question is how big a conduit must be so that you can run
those cables. Other important factors - don't drive holes
through structural supporting members (ie joists) for a
conduit that large. Many utilities have specific requirements
on everything from size of conduit to what kind of cutoff box
is permitted. But then if you have first consulted the
electric company, then these facts, unique requirements
demanded by each utility, were already provided.
"Jeffrey J. Kosowsky" wrote:
This is Turtle.
If you ask about the electric service being in conduit between the service
entrance and the main service box. I sure hope your going to get a Electrician
to do this job. Yes it must be encased.
Aluminum is ok but Copper is better in the long run for joints getting loose or
having connection burning off. Al. is called the poor man's wire.
That's interesting.... because the current 100A service doesn't appear
to be conduit -- it appears to be just a fat (2x1 inch oval), gray
Also, I asked our electrician who said you can always pay extra to put
in rigid conduit but it is not necessary. BTW both the electrician who
did the original job and the current electrician are licensed. Also,
the house passed inspection.
Maybe the wire is in some type of flexible plastic conduit that looks
just like wire :)
No, house was just inspected. Electrician is licensed and no
relationship. Again, I am just stating the facts, not arguing code or
not code. Also, maybe this stuff that looks like wire counts as conduit.
That's service entrance cable (SE), and it does not need to be run in a
conduit -- in fact, I don't think you're allowed to run it in a conduit.
I don't know about the 30 feet run of it inside the house, unless you
have a disconnect at the meter (and even then I don't know if you can
use SE for that long of a run.)
This is Turtle.
This is new to me of using SE cable in a basement to connect the meter pan to
the switch box and also going one end of the basement to the other in open air.
If you would have a short in the SE cable before getting to the switch box the
only breaker you would have is the 1,000+ amp breaker for the transformer to
protect it. Like you said , The only way I could see this would be a 200 amp
breaker & disconnect at meter pan to protect it before it gets to the switch
box. I will have to pass this by my City inspector on SE cable run in open air
30 something feet in a basement and being before the switch box main and after
the Meter pan. I would not want this in my house but NEC and city codes do let
some funny things go by that I would not want , like Al. Wire for lighting
I woudn't want it in my house either.
I was just tryin' to help identify what the OP has. If the service
conductors run more than 10' inside the house before they get to the
panel, there's gotta be an OPD (breaker or fuses) outside the house. I
don't think there's a limit to how far you can run the service
conductors outside the house without an OPD, but I've never needed to
look it up yet.
This is Turtle.
I know it is a problem for NEC and the International Mechnical Code would not
allow this without a breaker before the switch box. All 50 use these codes and
stick by them. Now he could be in Mexico or Canada and i could be wrong.
Here in New Jersey on a single family residence the 30' of wire does not
have to be in conduit, but it must be protected by a circuit breaker or
fused switch located just below the meter. On larger services for
commercial or industrial buildings it would have to be in conduit encased by
2" of concrete all around.
If aluminum is installed correctly you shouldn't have any problems for a
long time, but copper is still a better choice.
There is no reason to use conduit unless you anticipate the cable becoming
subject to abuse.
Here in Canada, ordinary NMD is perfectly code-acceptable for this, but, yup,
you MUST have a breaker/fuse box within 5' of the cable entering the
[There are _occasionally_ variations allowed, but you have to get prior
permission from the inspector.]
Given costs that I last saw for wire this size, 30' would be about the most
I'd go with copper before I'd consider using Al.
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.
From the 2002 NEC handbook
No maximum distance is specified from the point of entrance of service
conductors to a readily accessible location for the installation of a service
disconnecting means. The authority enforcing this Code has the responsibility
for, and is charged with, making the decision as to how far inside the building
the service-entrance conductors are allowed to travel to the main disconnecting
means. The length of service-entrance conductors should be kept to a minimum
inside buildings, because power utilities provide limited overcurrent
protection and, in the event of a fault, the service conductors could ignite
nearby combustible materials.
Some local jurisdictions have ordinances that allow service-entrance conductors
to run within the building up to a specified length to terminate at the
disconnecting means. The authority having jurisdiction may permit service
conductors to bypass fuel storage tanks or gas meters and the like, permitting
the service disconnecting means to be located in a readily accessible location.
However, if the authority judges the distance as being excessive, the
disconnecting means may be required to be located on the outside of the
building or near the building at a readily accessible location that is not
necessarily nearest the point of entrance of the conductors. See also 230.6 and
Exhibit 230.15 for conductors considered to be outside a building.
i'm curious why you are running the 200a SE cable so far inside the house.
my guess is that you are doing the new entrance in a different location than
where the old service was, and you will be putting the new panel where the
old one was, in order to reconnect branch circuits.
if so, you might consider putting the new panel just inside the building
(like normal), and then make a feeder run of #2 or 0, whatever, over to the
old panel. You don't necessarily need 100a ampacity on this run, as long as
the breaker size protects the feeder wire. Depending on what's in use on
the old branch circuits, you may be able to feed with quite a bit less than
Then feed new branch circuits out of the new panel.
Just a thought.
Well, this is the way the old feed went. It enters the house at one
end, goes through a 100A main breaker and then goes about 30 feet to
the other end of the house where the main 100A panel is.
We thought of various alternatives for the upgrade including:
1. Placing panel at entrance and moving all circuits to this new panel
-- however, then we would need to rewire all the branch circuits or
have some type of nasty junction box replacing the old panel
2. Placing a new 200A panel at the entrance and converting the old
panel into a 100A subpanel
-- however, we thought this might confusing and a PITA having the
two panels separated by the length of the house. Especially,
since given the mix of old and new wiring two circuits feeding
the same room could end up in different panels 30 ft away from
Therefore, we are planning instead to consolidate all the circuits at
the location of the old panel. In doing this we considered two
A. Place new large 200A panel next to the old panel and convert the
old 100A panel into a subpanel of the new panel. This would mean
leaving the bulk of the circuits in the old panel and keeping the
new main panel mostly unpopulated (but likely to fill in over
-- we chose not to do this since this seems a little kludgey with
the subpanel having more circuits than our new main panel
B. Instead, we are planning to replace the old 30 circuit 100A panel
with a new 42 circuit 200A panel in place which requires a bit more
effort to move over the breakers and reattach neutrals and
grounds. Then, we will move the old 100A panel to a location next
to the new 200A panel to hold any circuits after we run out of
space in the new panel.
Finally, rather than having a meter outside, then a main breaker just
inside, and then a 30 ft run over to the panels, we are thinking about
placing a combo meter/breaker unit outside replacing our old meter and
then entering the house and running 30 feet directly over to the new
panel. This has the benefit:
- Reducing costs (since no need for separate main breaker just
inside the house)
- Eliminating "extra" box inside the house
- Allowing fire dept easy access to electrical shutoff in case
Does this thinking make sense??
My understanding is that by having an exterior main breaker (shutoff),
the interior panel is considered a subpanel, and so the conductors
leading to it are feeders, not service conductors. I have a similar
situated, I elected to use 1/0 Al SER cable as my feeder cable; it is
stapled to the underside of the joists in my crawl space.
This might not fly with the inspector. If the old 100a panel is being gutted of
all circuits and simply being re-installed as a secondary subpanel, which would
likely have no circuits until the space is needed, it becomes "used equipment."
Better to just go with another new main-lug 100a panel next to the new 200a
panel for 35.00 - 40.00 extra and be done with it.
Makes sense. Or you could get a w/p outdoor main disconnect which holds not
only a 200a main but also at least one additional 2-pole breaker for an outdoor
hottub or pool panel.
In my jurisdiction, outdoor tubs and pools can not be fed from subpanels due to
proper grounding and bonding issues.
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