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
vol
Lee,
It possibly sounds like two inverters to me.
You also need to factor in whether or not the PVs will benefit from the
reflection of that bright sun you're enjoying there from snow. So, is it
ground mount or roof mount, angle of PVs (the shallower the angle, the less
benfit from s
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 batterie
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
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 dea
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 batteries. He uses the system mostly on weekends.
Winter came, the solar array was still set at about 30°, a
snowstorm covered th
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, bu
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
I to agree it is nice to have a disconnect means at the pv array. I
worry that touch safe fuses may give some one the wrong idea as they are
not safe to open under load. they will catch on fire. I like the
combiner with disconnect idea and I know there is a Huge player in the
combiner market th
Dick:
We are gong to install HU361 disconnects at the PV. Touch-safe fuse holders
are one way to apply disconnecting means rated at 600 VDC to a Sola Deck
device. Fusing at an array and GFDI at an inverter do not de-energize PV
feeders. Combiner fuses, if required, protect only adjacent arra
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
[mailto:re-wrenches-boun...@lists.re-wr
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 dumpi
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 would
An inspector can bump absolutely anything. That doesn't mean they've correctly
interpreted the code or made a decision that increases electrical safety, only
that they have the authority to call it anyway they like.
What constitutes a long DC circuit in a building? Ten feet, fifty feet? What if
it
Friends:
I am embarking on a 10 Kw ground mount grid-tie installation. The client
prepared for this installation some time ago by stubbing a PVC conduit
underground towards the future location of the PV array. Prior to
beginning this job, an excavation contractor intercepted the empty condui
I'm not going to say that the requirement makes very much sense, but
yes---the PE does test and approve the system in these situations.
Testing is up to the PE, and typically uses highly advanced testing
facilities; which might include things like a volt meter and clamp-on
ammeter for those espec
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 dis
William,
What about the "tested and approved" requirement? Does your PE also test and
approve the system?
Joel Davidson
- Original Message -
From: "William Korthof"
To:
Sent: Saturday, December 19, 2009 7:43 AM
Subject: Re: [RE-wrenches] Solar System Certification
Yes, Yorba Lin
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