On Sun, 24 Sep 2017 13:06:40 -0400, "Jim Wilkins"
wrote:


"Larry Jaques" wrote in message
.. .
On Sat, 23 Sep 2017 10:35:38 -0400, "Jim Wilkins"
wrote:

"Larry Jaques" wrote in message
...
On Sat, 23 Sep 2017 08:10:11 -0400, "Jim Wilkins"
wrote:

"Larry Jaques" wrote in
message
om...
On Thu, 21 Sep 2017 21:34:22 -0400, "Jim Wilkins"
wrote:
.....
I've been putting cheap analog meters on my solar panel
downleads
after losing a nice digital Wattmeter to possibly static
electricity.

Bummer. Aren't your panel frames, ground wires, and control
panel
face grounded? Which meter, Watt Meter (blue al), DROK, or
Bayite?


It's a stand-alone system at 24V or less, which is allowed to be
ungrounded. There is a ground rod for the generator when
connected.
The panels can be patched in parallel for 12V or series for 24V so
one
has to float. The lightning arrestors trip at 70-85V.

Isn't static electricity usually measured in the kV?


https://www.homepower.com/articles/s...ing-dc-systems
"Be sure to make that connection (between negative and equipment
grounding) in one place only."

I get the ground loop thing, but since they're not electrically
connected, I'm going to ground my frames and rails from a separate
ground right next to their end of the roof, for the unlikely
instance
of lightning. The redwood would be the most likely strike point,
with
the power poles coming a close second, and the house/panels 3rd.
SWAG
I'm glad I don't live in your Lightning Alley.


This is the meter that failed by reading high. I can't prove
static
caused it.
https://www.banggood.com/PZEM-031-DC...p-1111791.html

Perhaps they should rename it BangBad? (mindless Blue State humor)
PeaceFair looks a mite like a Bayite, enough that both could have
come
from the same factory. Perhaps I'll treat my Bayites a bit more
cautiously from now on, since I hadn't been thinking about static
damage.

Gotta get those panels UP!

When I was a test engineer I destroyed 20V-rated components by
applying 22V to them.

I think the marketing guys sell on the "destroy voltage" numbers
rather than the "running voltage" figures Engineering gives them,
thinking it will entice more purchasers. Time was, marketing used
to
have the interests of the company in mind. Unfortunately, that time
is long past. Now they think that higher sales numbers (even if
they
include all the free warranty replacements) are good. sigh

My favorite LED flashlights use a Cree XM-L T6 bulb running 900LM
(lumen) max, but Chiwanese vendors are calling them 2000, 2200,
2500,
5000, and 6000LM to grab sales. AFAIC, they're bright enough, have
a
zoom shroud, 3 brightness modes, flasher mode, and SOS mode, and
cost
only $5 on sale, so I'm happy.


The electrical system of a WW2 sub was similar to that of a hybrid
electric vehicle or a solar battery with generator backup:
https://maritime.org/doc/fleetsub/el...p3.htm#fig3-06

Verily! Rheostat clutches? Arc chutes? Luckily, our control
panels
are smaller and less expensive nowadays. I imagine that amperages
were slightly high in those boats. There were no figures quoted.

The battery overcurrent relay was set between 12,000 and 14,000 Amps.

That manual describes the details that modern automation lets us
ignore, unless you are the designer of the automation or are putting
together a home solar system with batteries and a generator. Mine has

I glossed over it, but didn't see much relevance. Looking again...


the extra complication of both 12V and 24V inverters which requires
floating some of the panels and being careful of cross connections.

Yeah, I bet.


A few month ago I posted a warning about the different types of
automotive replacement circuit breakers, since Type 1 automatically
reconnects after a timeout and Type 2 resets after power has cycled
off. Only Type 3 stays open until you push the button.

I don't recall seeing that. I use Type 3 exclusively. Button and
lever.


I'd like to have a new replacement copy or two of their battery
banks,
though.

And a shipyard crane to move them.

Ayup.


The operators had about 30 seconds to completely reconfigure the
complex switchboard from running on Diesels and charging batteries to
crash diving at full battery power. I need longer than that to change
channels (antennas) on the TV.

g That must have been fun, huh?

--
Stoop and you'll be stepped on;
stand tall and you'll be shot at.
-- Carlos A. Urbizo