Is this a code change in 2014 vs 2011 or merely a clarification? Vt has not
adopted 2014 yet. What was the original rationale for the 120% rule to apply to
conductors in addition to a panel bus?
Kirk Herander
VSE
> On Mar 4, 2014, at 6:20 PM, Brian Mehalic wrote:
>
> If the subpanel is at th
If the subpanel is at the end if the feeder, and there are no taps in between
the main and the sub then I don't see any reason that the conductors need to be
any larger than 200 A as there is no where on the feeder conductors where grid
and PV current will be additive.
The changes in 705.12 in
Solaredge 20 kw, 480 3-phase. Good point, but that may be irrelevant. The
feed-in subpanel is also powering unrelated loads, which use the neutral as
a conductor from the main panel. So 4 conductors from the main.
Kirk Herander
VT Solar, LLC
dba Vermont Solar Engineering
NABCEPTM Certified I
The other thing I could do is downsize the main to 190 amps or less. 190 +
60(pv) = 250 / 1.2 = 208 amps, exactly the 4/0 derate amperage.
Unfortunately I can't get away with downsizing the 60 amp pv breaker, unless
I could find a breaker rated to operate continuously at greater than 80% of
its tr
what inverter(s) are you using?In many cases the Neutral is not considered
a Current Carying Conductor by the Manufacturer and therefore you only have 3
CCC.
Al Frishman
AeonSolar
(917) 699-6641 - cell
(888) 460-2867
www.aeonsolar.com
On Mar 4, 2014, at 4:20 PM, Kirk Herander wrote:
> App
Approx.. 50 - 60ft.
Kirk Herander
VT Solar, LLC
dba Vermont Solar Engineering
NABCEPTM Certified Inaugural Certificant
NYSERDA-eligible Installer
VT RE Incentive Program Partner
802.863.1202
From: re-wrenches-boun...@lists.re-wrenches.org
[mailto:re-wrenches-boun...@lists.re-wrenches.
Yeah, I assumed you meant the four conductors. The exception would solve
your problem if it's physically possible.
How long of a run are we talking about? The cost difference shouldn't be
bad for a short distance.
Jason Szumlansk
i
Fafco Solar
On Tue, Mar 4, 2014 at 3:34 PM, Kirk Herander w
What is the length of the conduit to
the subpanel? That will determine whether to apply the derates.
R.Ray Walters
CTO, Solarray, Inc
Nabcep Certified PV Installer,
Licensed Master Electrician
Solar Design Engineer
303 505-8760
On 3/4/2014 1:34 PM, Kirk Herander wrote:
Whether or not a further derate has to be applied is the killer here, as I
am working with existing panels and conductors. In an old Code Corner(HP140)
J. Wiles goes through a similar scenario and calls out the allowable current
rating and conductor in 310.15, but makes no mention of applying addit
Both the bus and conductors need to be rated for 217 amps minimum. As you
mentioned, the bus is not a problem. The way I interpret it, the conductor
size required would be after derate factors are applied. The rating of the
conductor is ultimately dependent on the derate factors.
If you can locate
The conductors have to be rated for 200A as normal. Fault current can only
come from the grid.
While the total available current on the bus of a panel is the total of the
source breakers, in the conductors, grid and solar power cancel out and the
total is not the sum of the two.
On Tue, Mar 4, 20
Hello,
I have a 225 amp 3-phase main lug sub-panel protected by a 200 amp breaker.
My inverter breaker feeding the sub panel is 60 amps. So 225 a bus x 1.2 =
270 amps. That's less than the sum of the two breakers of 260 amps, so no
issue there. The conductors between sub and main panel have to be
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