I can see your point but I know from direct experience that the GFCI in
an XW system will trip during a close lightning strike. I have seen this
along with a few clients. The XW system has a series of escalating faults
that will shut down the inverter if the strike is close. To me it is worth
it to have an unattended system shut down to protect itself.
Dave Angelini
Offgrid Solar
"we go where powerlines
don't"
http://members.sti.net/offgridsolar/ [1]
e-mail offgridso...@sti.net
[2]
text 209 813 0060
On Mon, 22 Jul 2019 13:14:36 -0700, William Miller
wrote:
Wrenches:
Here is a question that has bothered me for some
time: If one is using a GFD (ground fault detection) breaker on a PV
feeder(s) to a battery inverter system, the state of the industry is to use
a breaker with an extra 0.5 or 1 amp pole. This section of the breaker
connects, or bonds the DC negative, or grounded conductor, to the grounding
system.
In order for the GFD breaker to work one needs to isolate the
grounded bus bar (negative). If there is a ground fault the breaker opens
and breaks the bond.
This goes very much against my conceptualization of
how a bonding system should work. The bond should never be broken,
particularly when there is a fault in the system. When this breaker opens,
either manually or by an overcurrent condition on any pole, the DC bond is
removed for all portions of the DC system.
There is a prominent
personality in the industry that often presents academic opinions on solar
related electrical issues in articles and in seminars. This person claimed
to have invented this GFD system, but when pressed to comment on the
concerns mentioned above, changed the subject.
I believe ground fault
protection is important. I just don't believe the method the industry has
offered is really effective in solving the issues presented in a ground
fault scenario.
I believe similar issues present on non-battery PV
systems with the simple fuse in the ground system found on many inverters.
I know some troubleshooting guides warn of energized parts in ground fault
conditions.
Have any of you thought about these concerns? Are my concerns
valid? What are your policies on this subject?
Thanks in advance for any
insight.
William Miller
Miller Solar
17395 Oak Road, Atascadero, CA
93422
805-438-5600
www.millersolar.com [3]
CA Lic. 773985
Quote of
the month: "As they age, batteries transition from energy
storage
devices to energy consuming devices." W. Miller
--
Links:
------
[1] http://members.sti.net/offgridsolar/
[2]
mailto:offgridso...@sti.net
[3] http://www.millersolar.com/
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