On 2017-03-13, Larry Jaques wrote:
On Sun, 12 Mar 2017 10:30:01 -0400, "Jim Wilkins"
wrote:
"Steve W." wrote in message
news
David R. Birch wrote:
[ ... ]
Has anyone here done this or have more info?
Since solar runs 12-48vdc battery systems and garage openers run at
120vac, it would have to be run on an inverter. I've never seen a
dedicated system for a garage door.
With a bit of re-design, it could be run with a 12V or 24V DC
motor, and a regulator to provide the desired voltage for the
electronics.
[ ... ]
Solar panel voltage and load current are useful to check during setup
but I don't think they are worth the cost of dedicated meters unless
you have problems or keep tinkering with it. An ammeter in the load
cable will affect the low voltage cutoff.
By what, 0.3v (a diode drop), Jim? Will a shunted ammeter also cause
troubles like this? What's your depth of discharge, anyway? Sounds
too deep.
Most older shunted ammeters have a 50 mV movement and a shunt to
assure that at the maximum current, the output is 50 mV -- a lot less
than a diode drop.
My system uses non-gendered Anderson Powerpoles to connect the
components and a meter like this can be temporarily inserted to
measure voltage and current.
Wish I had the good luck you guys seem to with those, but the lone
pair I've used has been trouble 2 out of 3 times I've used it.
If you have the right crimper for the wire you are using (and
there are various sized pins to match, all of which fit the same
blocks), they can be very good. The one trouble which I was fighting in
the power input to a 2-meter transceiver was eventually traced to an
intermittent fuse in an inline holder just upstream of the PowerPole
connector.
Soldering the pins is bad news, however. It makes them rotate
at strange angles in the block and makes for intermittent connections.
[ ... ]
The Amp-Hours total is useful on solar systems. It will preserve the
reading if you add a 9V battery to keep it powered through the JST
connector (from an RC hobby store.) Watt-Hours is less useful because
the battery discharges at a lower voltage than it charges.
Huh? 'Taint a 9v connector.
There is a tiny 3-pin connector lurking beside the input power
cable. (This on my "Turnigy" brand metering module) which says that it
accepts between 4.8 V and 60 V And it is rated to measure current up to
130 A. It constantly displays instantaneous current and voltage, and a
smaller part of the display cycles through a number of readings,
including A-H, peak amps, and several others.
[ ... ]
https://en.wikipedia.org/wiki/American_wire_gauge
If you are accustomed to 120V wiring the relatively higher resistance
loss at 12V is surprising. 25' of 14 AWG wire pair drops 1.25V at 10A.
In other words you may want the battery very close to the AC inverter.
Yeah, 6' or less, please.
Unless you have serious wire available. How much 4-0 wire would
it take to produce the same drop? :-)
The 120V wiring to the motor in the center of the ceiling could be
longer and the wiring to the solar panel controller long enough to put
it within reach on the wall. An external port like a weatherproof
trailer connector would let you charge a dead battery to open the
door.
I'll be running 4ga for the 900W heater element @ 35'.
Better -- but if you really want to minimize drop go for 4-0
wire. :-)
Enjoy,
DoN.
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