William,
What about the tested and approved requirement? Does your PE also test and
approve the system?
Joel Davidson
- Original Message -
From: William Korthof wkort...@eesolar.com
To: re-wrenches@lists.re-wrenches.org
Sent: Saturday, December 19, 2009 7:43 AM
Subject: Re:
Regarding the DC disconnect, the 2008 Handbook 690.14C(1) comments, These
requirements generally prohibit long runs of PV source and input circuits
inside a building before reaching the required PV disconnect. A short conductor
run through a wall at the point of first penetration to reach a
William,
Not sure I understand how buried PV runs protected by touchsafe fuses in
combiner boxes at the array and GFCI protection at the inverters constitute a
fire hazard.
That's not saying I disagree with your disconnect here. I don't. If it was a 1kW
system, would you still install one? I
We use chrome oxide collectors exclusively.
What I'm getting at is that the system will satisfactorily self regulate.
Just from all the combined parasitic losses, a typical flat plate system
will top out around 180F max.tank temp. in an average summer climate even
without nighttime heat
We have been looking at the Blue Oak line of fused combiners/load break
rated DC disconnects, but can't get the right fit / cost.
Maybe a couple would do the trick at the array for you?
-Glenn Burt
_
From: re-wrenches-boun...@lists.re-wrenches.org
William,
I'm not sure what the struggle is about here. If you have a combiner box,
you should always have a disconnect nearby to service the fuses. The 2011
NEC will require such a disconnect. It is a no-brainer on a ground mounted
system. A roof-mounted residential system of 4 strings or less
Wrenches.
I need some help on inverter sizing. In Montana we have a lot of
cold weather with bright sun. What about the following
With an array of 50 panels at 235-watts, I would select an 11.4 KW
string inverter. The string sizing chart says the 11.4 KW inverter
would be fine,
William,
Put the inverters at the array. Run the AC underground. If the AC feeder
gets dug up by some rowdy backhoe operator in the future, the breaker (or
series of breakers) will open, de-energizing the circuit immediately (and
maybe the main to the residence at the same time).
If you are
William,
It is common in our area to install underground, unfused, transformer secondary
laterals. The utilities require 3 feet of cover and marker tape located 12
below grade. I can't find a requirement for marker tape in the NEC. That's not a
reason not to use it. It's inexpensive available
Lee,
The Sunny Island will shut down entirely to protect the batteries.
Dick Ratico
Solarwind Electric
--- You wrote:
Wrenches.
I have a customer with a stand-alone system with an XW inverter, XW
controller, pole mounted array of four 235-watt panels, and 4 of the
8D gel
Hello all,
While this may be excellent advice, I think it would be good to clarify that
this may apply primarily to grid tied systems.
In Off Grid systems we have different considerations, such as (a) we are
working with lower voltages and need to limit the size of the wire and the
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