[RE-wrenches] Backup System Blues

[Drake]

I had a Radian blow up a light bulb when first commissioned. It 
literally exploded the bulb. The bulb had worked fine with grid power 
minutes before.

Testing the inverter voltage showed no problems. It worked fine after 
the initial issue. It remains one of those uncomfortable issues.

At 09:50 AM 6/15/2016, you wrote:
>Hi All;
>
>I'm in the process of finishing a grid tie with battery backup 
>system, and besides the many pitfalls of this type of work, I 
>destroyed a Tripp lite surge suppressor when I turned on the system.
>The system has a pair of the new Outback VFXR 3524 inverters wired 
>in 120/240 series config. with Mate 3.
>I measured before and after, and the output was a steady 120vac (240 
>between them), frequency was 59.99 to 60.00 Hz.
>I also measured THD at about 2.5%, which is much better than the 
>grid here ( about 5%)
>The system was in off grid mode, running several lights and other 
>loads, when I switched on the breaker to the office.  Immediately 
>the slave inverter shut down with an AC short circuit error.
>Upon examining the computer equipment, I was greeted with the 
>classic "smoke let out of the box" scent, and traced it to the 
>Tripplite surge suppressor.  This morning, I opened it up to 
>examine, and one set of capacitors had blown.  The Triplite (which 
>I'm not that familiar) has several outlets each with an inductive 
>coil and cap, each is labeled with a higher level of protection.
>The one that blew was labeled 120 dB ( or max) protection.
>So the question is:  Did this just blow randomly, or is there 
>something with the Outback power output that isn't right?
>I don't have an Oscilloscope, but I could better isolate the various 
>harmonic Distortion to its separate components to see if maybe there 
>is a harmonic spike somewhere the Tripplite didn't like?
>I didn't notice what was plugged into that outlet, but I will check 
>today.  The actual equipment is just the usual home collection of 
>ink jet printers, and lap tops.  The Tripp lite however looks pretty 
>high end ( and old) and was immediately my suspect, as soon as I 
>looked under the desk.  The model is Tripp Lite Isobar Ultra 8, and 
>is apparently still available.
>https://www.tripplite.com/isobar-8-outlet-surge-protector-12-ft-cord-3840-joules~ISOBAR8ULTRA/
>This is venturing outside my normal area of expertise and into the 
>Murky world of what's actually inside those electronic gizmos.
>
>As always, thanks in advance for all your sage advice,
>
>--
>R.Ray Walters
>CTO, Solarray, Inc
>Nabcep Certified PV Installer,
>Licensed Master Electrician
>Solar Design Engineer
>303 505-8760
>
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