Re: Wind Solar unreliable compared to Gas Coal Nuclear

"Scout"  wrote in message news:[email protected]...
"Jim Wilkins" <[email protected]> wrote in message
news:[email protected]...

>
> I briefly covered some of the advantages and disadvantages of that 
> approach when describing my DIY solar system. To expand, in order to 
> design one you need a good quantitative understanding of your requirements 
> and to study and understand the capabilities of the separate modules and 
> how they interact.
>
> Specifically an AC refrigerator draws a starting surge current that may 
> exceed 10 times its run current. You won't find that surge current in its 
> spec sheet.

No, but if you contact the manufacturer directly they should be able to
supply that information for any specific model, contact the compressor
manufacturer if it was sourced from a different manufacturer. Worst case
would require real world testing, or be prepared for the worst case. About
the only think I might add is a delay to prevent a rapid restart if power is
interrupted.

But this was covered above under the "research and consideration" clause.
If you don't want to do it.. then design your system for worst case.. I
pretty much promise a packaged system isn't necessarily designed to start
every fridge out there either.
-------------------------

I listed design considerations. Most aren't difficult, you just have to know 
to look for them, like breakers marked for DC . That fell under my job 
because the electrical engineers weren't trained in practical considerations 
like switch contact rating. One I didn't mention is that indoor solar DC 
wiring is to be in metal conduit, which brings up conduit wire fill and 
temperature rise derating concerns.

Determining starting surge current can be difficult if the equipment is 
imported or old. Getting specs from China is particularly hard, I went 
directly to the circuit designer (Liu Liang) for some. Fortunately I haven't 
had to call Inner Mongolia about a product that was made there. I have a DVM 
that claims to measure peak values but the result aren't close to the 
readout for digital oscilloscope traces. Some refrigeration compressors have 
a thermistor surge limiter that delays an immediate restart attempt, others 
don't and rely on the 10,000A or more surge capacity of the power grid 
(breaker short circuit interrupt rating). You have to get past customer 
service to engineering to find out, which requires knowing how to talk like 
an engineer yourself. Otherwise I'll be treated like a woman having her car 
repaired.

The IWISS crimper can be awkward and tricky to use and tends to lengthen the 
crimp sleeve and squeeze metal flash out between the jaws. It's my last 
resort if I don't have a better tool.