[RE-wrenches] Lightning protection (was Delta LA's)

[Dave Palumbo]

I agree with Augusts' point. We use Delta LA's because some manufacturers
(OutBack and Trace) recommended using them years ago. So, sort of the same
reasoning Jay was saying about insurance. 

 

Unscientific evidence from 22 years of experience with off grid systems in a
fairly high lightning prone area suggests the following. Systems installed
poorly (little care given to good grounding), by do-it-yourselfers mainly,
have had a much higher incidence (with or w/out Delta's in the system) of
inverter and charge controller failure than systems where myself, and or my
crew, installed the system with good grounding techniques. We have had a
very low rate of lightning damage with our own installs over the years. Both
with the grid-tied, or off-grid, equipment.

 

What Ray Walters said was the truth. Resistance to ground should be very
low. How many dollars is that tester you use Ray? We don't own one. On the
wish list. We get the ground Rods in wet earth, bond to our Sched 40/80
steel pipe masts that are encased in concrete when using TPM's. Bond to
drilled well casings (in addition to typical grounding) when practical. When
in doubt, get more copper in the earth. I learned from a lightning pro who
is tasked with protecting police/firefighter/public safety communication
towers here in hilly Vermont. Towers up high, on sites with shallow soils.
Challenging situations for sure. They bring in graphite and pore that into
deep holes they drill into the bedrock and then fasten their ground rods in
these holes. The tower is surrounded with several of these ground points
which are bonded together. There are other devices that are used on the
tower to get static charges to ground that I won't get into. 

 

This lightning protection guy was chuckling at my use of the Delta cans and,
with my permission, cut one open for inspection to educate me on the lack of
substance to the design. He did not think that they would be very effective
99% of the time. But again we use them because there is not much else out
there that is much better, for less than big dollars. Robin Gudgel (MidNite)
has said that they will have a product, but I'm still waiting on my
"Classic" beta units also. Has anyone got an opinion on the OutBack surge
suppressor?

 

Here is a company that says they have a product in UL now. Matt has been in
touch with me over the past couple of years with questions on our PV
systems. So, maybe this will be something.

<< Hi Dave,

I just wanted to keep in touch and let you know that our SPDEE DC Electrical
Surge Protector is currently being evaluated at this time for UL 1741
Certification.  

The approximate finish date currently is late November 2010.

The demand for a UL 1741 Electrical Surge Protector from the Solar PV
Industry prompted our company to move forward with this process.

Matt Smith 
APT Industrial & Specialty Sales 
(800) 237-4567 
(727) 535-6339 x 232 
Fax (727) 539-8955 
smithm at apttvss.com >>

 

David Palumbo 

Independent Power LLC

Offices in Lamoille and the Champlain Valley, Vermont

802.888.7194 

www.independentpowerllc.com 

NABCEP Certified Solar PV InstallerT

Vermont RE Incentive Program Partner

 

 

 

 

From: re-wrenches-bounces at lists.re-wrenches.org
[mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of August Goers
Sent: Tuesday, September 14, 2010 9:01 PM
To: RE-wrenches
Subject: Re: [RE-wrenches] Delta LAs

 

Jay - 

 

I can see that point, but does that really effect insurance payout? It seems
like one could argue that a properly installed system with proper grounding
inspected by a building official has a lot more clout than and little grey
cylinder next to the inverter or disconnect.

 

Please all wrenches, correct me if I'm wrong but I can't remember a single
time when there was a post about an actual lightning strike and a lightning
arrestor actually doing its job - meaning that an arrestor took a hit and
protected the array and or inverter. I've heard plenty of stories about
blown lightning arrestors and good equipment but no one seems to know what
caused the situation. It might be that lightning is hard to track and I
agree with that. And lightning might have been the cause. It would be great
to track lightning-fried installations to see what happened and what could
be fixed. If lightning arrestors are the solution then by all means we
should install them. Most of the time I think that proper grounding is the
solution although I wish that field experience would prove the point. 

 

What do you think?

 

-A

On Tue, Sep 14, 2010 at 5:28 PM, jay peltz <jay at asis.com> wrote:

I also live in a area without much lightning, however I install one in most
systems for the simple reason of insurance.
If there is lightning damage, the insurance company can't use that as a way
to not pay any claims.
ie cheap insurance.

jay

peltz power

On Sep 14, 2010, at 8:39 AM, August Goers wrote:

> All -
>
> I guess my thought is a little off topic, but are lightning arrestors even
worth using at all? My logic has always been that if lightning does indeed
strike that it's likely going to blow the arrestor and and inverter. We
don't have much of a lightning issue issue in the Bay Area so I don't have
any direct experience.
>
> Best,
>
> August
>





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