XPost: talk.politics.guns, sci.energy   
   From: muratlanne@gmail.com   
      
   "Scout"  wrote in message news:unrbtk$3f6el$1@dont-email.me...   
   "Jim Wilkins"  wrote in message   
   news:unpab4$334vp$1@dont-email.me...   
      
   >   
   > 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.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)