to size the conductor
and overcurrent device.
Bill.
From: re-wrenches-boun...@lists.re-wrenches.org
[mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Troy Harvey
Sent: Friday, April 05, 2013 3:38 PM
To: RE-wrenches
Subject: [RE-wrenches] Fuse sizing in battery circuits
...@lists.re-wrenches.org
[mailto:re-wrenches-boun...@lists.re-wrenches.org] *On Behalf Of
*Troy Harvey
*Sent:* Friday, April 05, 2013 3:38 PM
*To:* RE-wrenches
*Subject:* [RE-wrenches] Fuse sizing in battery circuits
I've got a question about battery string fusing. Typically we size
the wire from
To: RE-wrenches
Subject: Re: [RE-wrenches] Fuse sizing in battery circuits
First, a water main is no longer allowed to be used as the primary grounding
electrode by itself, it needs an additional electrode added to it 25053(D)2.
You still are required to bond to it 250.104(A)1, but it doesn't count
[mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Ray Walters
Sent: Tuesday, April 16, 2013 2:22 PM
To: RE-wrenches
Subject: Re: [RE-wrenches] Fuse sizing in battery circuits
First, a water main is no longer allowed to be used as the primary grounding
electrode by itself, it needs
This is a fairly complicated issue. I agree that an ungrounded
battery system is safer than a grounded one, since the hot wire will
not arc to the casing of the enclosure.
If a system has a charge control and an array, the negative wire of
the array usually needs to be grounded (or have a
Hi Drake;
Read down a bit more and 250.166(C) and (D) limit the size of the GEC to
#4 or #6 max., depending on what electrode is used.
This used to not be the case, and systems in the 90s had 4/0 cable to a
5/8 electrode: which just like your 1/2 pipe example was absolutely
ridiculous.
*To:* RE-wrenches
*Subject:* Re: [RE-wrenches] Fuse sizing in battery circuits
Hi August;
250.162(A) says operating at greater than 50 v, which a 48 v nominal
system operates most of the time at over 50 v, at least when solar charging
and/or selling back.
We used to get dinged many years ago
Hi Ray,
Thanks for that information. I'm glad they covered that. I never
install more than a #4.
The question I'm still not sure of is weather or not we need to
ground the DC. I always have run a GEC to the DC. It would be great
if we didn't need to do so on the Sunny Islands especially,
] Fuse sizing in battery circuits
Hi Drake;
Read down a bit more and 250.166(C) and (D) limit the size of the GEC to
#4 or #6 max., depending on what electrode is used.
This used to not be the case, and systems in the 90s had 4/0 cable to a 5/8
electrode: which just like your 1/2 pipe example
-wrenches-boun...@lists.re-wrenches.org
[mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Ray Walters
Sent: Tuesday, April 16, 2013 12:52 PM
To: RE-wrenches
Subject: Re: [RE-wrenches] Fuse sizing in battery circuits
Hi Drake;
Read down a bit more and 250.166(C) and (D) limit the size
-boun...@lists.re-wrenches.org
[mailto:re-wrenches-boun...@lists.re-wrenches.orgre-wrenches-boun...@lists.re-wrenches.org]
*On Behalf Of *Drake
*Sent:* Wednesday, April 10, 2013 5:52 AM
*To:* RE-wrenches
*Subject:* Re: [RE-wrenches] Fuse sizing in battery circuits
boB,
SMA does recommend protecting
Hi August;
250.162(A) says operating at greater than 50 v, which a 48 v nominal
system operates most of the time at over 50 v, at least when solar
charging and/or selling back.
We used to get dinged many years ago for using breakers rated at 50v dc
on 48 v systems. John Wiles used to insist
To: RE-wrenches
Subject: Re: [RE-wrenches] Fuse sizing in battery circuits
Steve,
So if we wanted to ground the negative would we
literally run a ground wire to one of the
battery terminals? Is there anything in the NEC
that governs this? What are the deciding factors
when deciding to ground
and any attachments thereto.
Thank you.
From: re-wrenches-boun...@lists.re-wrenches.org
[mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of August Goers
Sent: Wednesday, April 10, 2013 9:45 AM
To: RE-wrenches
Subject: Re: [RE-wrenches] Fuse sizing in battery circuits
Hi All
To: RE-wrenches
Subject: Re: [RE-wrenches] Fuse sizing in battery circuits
Hi All -
As a slightly separate topic, should we fuse both the positive and negative
battery lines with an SMA Sunny Island? I believe that the negative is grounded
so should not be fused but I've heard conflicting stories
a good clue as to how to size the
conductor and overcurrent device.
Bill.
From: re-wrenches-boun...@lists.re-wrenches.org
[mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Troy Harvey
Sent: Friday, April 05, 2013 3:38 PM
To: RE-wrenches
Subject: [RE-wrenches] Fuse sizing in battery
If anyone would like an Acrobat version of this article, you can find it
here:
ftp://ftp.re-wrenches.org/pub/hp27_pg26_freitas.pdf
William Dorsett wrote at 07:00 AM 4/9/2013:
This topic comes up often enough
that we ought to mention a yellowed article in Home Power, (1992 Issue
27, pg 26).
Those 250 amp and 175 amp breakers we have used for many many years now
have an AIC of 50,000 amps at 125 volts and if you look at the curve, at
48 volts
they are around 100,000 amps. I think that this information is on the label
of the breaker.
How many problems have you had with the
Allan,
that is a good graph. Thanks. The time vs current is way different than whst
I've seen from fuse charts in the past.
I'd rather use DC-breakers, but I'm having trouble finding 350AMP DC breakers
for 350MCM cable. Any resources?
thanks,
Troy Harvey
-
Principal
Harvey
*Sent:* Friday, April 05, 2013 3:38 PM
*To:* RE-wrenches
*Subject:* [RE-wrenches] Fuse sizing in battery circuits
I've got a question about battery string fusing. Typically we size the
wire from the batteries to the inverter based on continuous rating
procedures (max power/efficiency
...@lists.re-wrenches.org');
[mailto:re-wrenches-boun...@lists.re-wrenches.org
javascript:_e({}, 'cvml',
're-wrenches-boun...@lists.re-wrenches.org');] *On Behalf Of
*Troy Harvey
*Sent:* Friday, April 05, 2013 3:38 PM
*To:* RE-wrenches
*Subject:* [RE-wrenches] Fuse sizing
I've got a question about battery string fusing. Typically we size the wire
from the batteries to the inverter based on continuous rating procedures (max
power/efficiency)*125%.
However a 6kW inverter, can peak at 12kW for 5-10 seconds, doubling the source
current. That is no big deal for the
. That will give you a good clue as to how to size the conductor
and overcurrent device.
Bill.
From: re-wrenches-boun...@lists.re-wrenches.org
[mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Troy Harvey
Sent: Friday, April 05, 2013 3:38 PM
To: RE-wrenches
Subject: [RE-wrenches] Fuse sizing
3:38 PM
*To:* RE-wrenches
*Subject:* [RE-wrenches] Fuse sizing in battery circuits
I've got a question about battery string fusing. Typically we size
the wire from the batteries to the inverter based on continuous
rating procedures (max power/efficiency)*125%.
However a 6kW inverter, can peak
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