[RE-wrenches] Delta LA's

Fri Sep 3 13:02:56 PDT 2010

Take a look at Citel lightning protection. They install on a din rail. We
are installing a 15 kw array for Acadia National Park and they were spec'd
for the project. It will be our first time using them but they look
promising.

http://www.citelprotection.com/ac_surge.htm

Daryl

> "I've also wondered if we should be fusing these things. One hand says
> definitely yes, on the other hand, a big lightning strike would trip the
> fuse, before the Delta could do its job."
>
>
>
>
>
> I think a big lightning strike would jump the fuse like it wasn't there.
> So
> the fuse would really make no difference at all.
>
> Midnite has an arrestor coming that looks like it has some good
> possibilities and a UL listing! It also has a light system to show if it
> has
> been activated.
>
>
>
> I also have seen lightning damage and the delta seemed unharmed each time.
>
> We need to keep in mind that there is some luck involved; NOTHING is going
> to stop a lightning bolt that just traveled 10 or 20 miles across the sky,
> so it jumping a meter socket or fuse / breaker would not be hard to
> understand.
>
>
>
> Later,
>
> Bob
>
>
>
>
>
>
>
>
>
>
>
> From: re-wrenches-bounces at lists.re-wrenches.org
> [mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of R Ray
> Walters
> Sent: Thursday, September 02, 2010 3:42 PM
> To: RE-wrenches
> Subject: Re: [RE-wrenches] Delta LA's
>
>
>
> I know, as Bill pointed out, that the Deltas are supposed to be mounted on
> the exterior to allow the damage to stay outside of the combiner box. But
> I've also seen a lot of old Deltas damaged by the sun, and seen them
> cracked
> off at the 1/2" nipple attachment point, which then leaves exposed THHN
> conductors against the edge of the knock out. Just bumping one with your
> foot or shoulder could crack the plastic.
>
>
>
> We just finished a project with BOS combiners, and I mounted the Deltas to
> the backing plate inside using a 2" PVC conduit clamp. In this case, the
> AHJs were very concerned with sealing all KOs on the sides of jboxes, so
> we
> would have had to mount the Deltas on Myer's Hubs. Clunky, and we didn't
> have 1/2" hubs.
>
> If conditions allow, I do prefer to hang them off the bottom of a box, as
> long as they're protected from physical abuse. Side mounting is definitely
> asking for trouble in many situations, they're just too easy to snap off.
>
> I've also wondered if we should be fusing these things. One hand says
> definitely yes, on the other hand, a big lightning strike would trip the
> fuse, before the Delta could do its job.
>
> BTW, with over 200 projects in lightning territory, I've never actually
> had
> a Delta blow itself while protecting the system. Plenty of lighting
> damage,
> though, with the Delta still just sitting there.
>
> Anyone using the DIN rail mountable equipment from Citadel?
>
>
>
> R. Walters
>
> ray at solarray.com
>
> Solar Engineer
>
>
>
>
>
>
>
>
>
> On Sep 1, 2010, at 6:32 PM, Dave Palumbo wrote:
>
>
>
> I am concerned with Delta LA 600VDC cans being mounted exterior from
> J-boxes
> (or disconnect switches) on ground mounts.
>
> I remember hearing  from an old hand that these devices can fail in a
> manner
> that could possibly expose the wiring to human hands. The wires would have
> high voltage DC potential. Not  something we need in our industry.
>
>
>
> Am I worrying about something that can't happen? Or should these be in PVC
> boxes?
>
>
>
> David Palumbo
>
> Independent Power LLC
>
> Offices in Lamoille and the Champlain Valley, Vermont
>
> 802.888.7194
>
> www.independentpowerllc.com <http://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 North
> Texas
> Renewable Energy Inc
> Sent: Tuesday, August 31, 2010 10:07 PM
> To: RE-wrenches
> Subject: Re: [RE-wrenches] Testing LSAs
>
>
>
> For the first time since 2004 we got a residential PV red tag for
> non-listed
> surge supressors. I just took them off and replaced them after we got the
> green tag. Of course he also red-tagged the copper ground plate because it
> was not thick enough. Go figure....
>
>
>
> Jim Duncan
>
> North Texas Renewable Energy
>
>
>
>
>
> -----Original Message-----
> From: re-wrenches-bounces at lists.re-wrenches.org
> [mailto:re-wrenches-bounces at lists.re-wrenches.org]On Behalf Of Andrew
> Truitt
> Sent: Tuesday, August 31, 2010 8:09 PM
> To: RE-wrenches
> Subject: Re: [RE-wrenches] Testing LSAs
>
>
>
> Question: Since the Delta lightning arrestors are not UL Listed, do they
> threaten the UL compliance of the PV system as a whole?
>
>
> - Andrew Truitt
> Currently of Standard Solar
> Free agent in the Denver area as of 10/6/10
>
>
>
>
> On Tue, Aug 24, 2010 at 6:02 PM, Peter Parrish
> <peter.parrish at calsolareng.com> wrote:
>
> I would think that an ohmmeter set to the 10 Mega-ohm setting (or the
> highest setting possible), would be the first test. I would like to see
> something on the order of 750 k-ohms (3/4 of a mega-ohm).
>
> But the system should be tested at a higher voltage, than that available
> from a DMM. Apply 240 Vac and measure the RMS current. It should be should
> be 0.3 mA or less.
>
> Finally, these puppies really need to be tested at much higher voltages,
> perhaps someone knows how to use that megohmmeter to test? What does the
> manu recommend, "if suspect, throw it away and buy a new one"?
>
> - Peter
>
> Peter T. Parrish, Ph.D., President
> California Solar Engineering, Inc.
> 820 Cynthia Ave., Los Angeles, CA 90065
> CA Lic. 854779, NABCEP Cert. 031806-26
> peter.parrish at calsolareng.com
> Ph 323-258-8883, Mobile 323-839-6108, Fax 323-258-8885
>
>
> ________________________________________
> From: re-wrenches-bounces at lists.re-wrenches.org
> [mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Kristopher
> Schmid
> Sent: Tuesday, August 24, 2010 1:30 PM
> To: 'RE-wrenches'
> Subject: [RE-wrenches] Testing LSAs
>
>
> What is the best method for testing the integrity of a DC and/or AC
> lightning surge arrestor?  Specifically, i use the Delta LA units.  I know
> they should be replaced if they look Bar-B-Qued, but otherwise...?
>
> Thanks,
> Kris Schmid
>
> Legacy Solar
> 864 Clam Falls Trail
> Frederic, WI 54837
> 715-653-4295
> solman at legacysolar.com
> www.legacysolar.com <http://www.legacysolar.com/>
>
>
>
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>
> --
> "Don't get me wrong: I love nuclear energy! It's just that I prefer fusion
> to fission. And it just so happens that there's an enormous fusion reactor
> safely banked a few million miles from us. It delivers more than we could
> ever use in just about 8 minutes. And it's wireless!"
>
> ~William McDonough
>
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