I blew up my inverter

Chuck2205Chuck2205 Posts: 2Registered Users
edited July 23 in Solar Beginners Corner #1
Last year, I sold everything and moved to the Philippines.  Most everything is cheap here, except the electric.  So, I had a Solar PV system set up with battery back up.  The inverter/charger is a Must PV3500 pure sine wave solar inverter that apparently has a 12KW capacity.  Now, when I was in the states, I had a grid-tie system for 17 years and that was zero maintenance, forget about it and love your electric bill.  I thought this system would be the same.  The electric goes out a lot here, so I wanted the battery backup, but I seem to be in over my head as this is a whole different animal.   I took a shower with an insta-hot electric water heater (well after dark, so the inverter was shut down) and 3 minutes into the shower, the inverter apparently started shooting out fireballs.  It turns on, but it apparently can't boot up into a working state.  The installer says neither he nor the manufacturer is at fault and it will need a new controller board at about US$1400.

It seems to me that any decent inverter would have a safety that would shut itself down when there's too much draw instead of blowing itself up.  Is that a silly thought, or should I look for a competent installer or perhaps an inverter that's not made in China?  Or am I totally naive?
Tagged:

Comments

  • mcgivormcgivor Posts: 2,058Solar Expert ✭✭✭✭
    edited July 23 #2
    Sorry to hear, is this the 4KW version, if so the 12KW rating is for 20 ms. What is the wattage of the shower heater, there are so many, some exceed 4Kw, should it have protected itself? It should have but there may be something else. Tropical climates have geckos, they love to crawl into devices, I lost an inverter due to them, all my equipment is now protected with stainless steel mosquito mesh and play dough stuffed into condiuts. As far as the quality goes, no idea with Must equipment, but $1400 for a replacement board is close to what a Schneider Conext 4024 230 costs, but it requires a separate charge controller and control panel add around  $750, just for comparison with quality equipment. Tell us more about your system, there may be other factors.

    Is this the unit you have? https://www.mustups.com/pv3500-mppt-series/
      1500W, 6× Schutten 250W Poly panels , Schneider 150 60 CC, Schneider SW 2524 inverter, 8×T105 GC 24V nominal 

  • jonrjonr Posts: 1,032Solar Expert ✭✭✭✭
    Yes, a good inverter will protect itself from overload, especially with a simple resistive load.   So barring damage (like geckos), it's either a poor design or defective.   I'd replace it with a good name brand inverter.
  • EstragonEstragon Posts: 2,609Registered Users ✭✭✭✭
    Just to clarify, is this basically a solar and battery backup connected to grid power, or totally off-grid?

    Lots of possibilities for a dead board. Was there any lightening in the area at the time?

    As Mcgivor notes, now might be a good time to look at overall system needs and plan accordingly in buying replacement gear.
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • Chuck2205Chuck2205 Posts: 2Registered Users
    I really appreciate the comments.  
    Yes, the unit I have is the one you linked, mcgivor.  We do have a lot of geckos.  The installers tell me the system is well grounded for lightning and it was not storming that day, so no lightning.  The heater is a Smart 18E, which pulls 3.5kW.  So, I guess that's going to max the inverter right there.
    https://www.alphamalaysia.com/18e

    We are not off-grid.  The inverter switches to grid power at night to save the batteries for when we lose grid power (which happens often here).  There are 8 gel-type batteries 19.2kW.  The solar panels are 18 Maharlika 280W panels.

    I have since moved the shower heater to the grid-only breaker box where I already had 2 huge air conditioners wired because I knew the inverter couldn't handle those.

    Mainly, I'm wondering if I should trust the installers to replace the board, or if this is going to happen again because the inverter isn't protected as it should be.  Note: the actual board is about US$915.  Customs charges are $300.  Then there's taxes and I'll need to get the technicians here by boat - it's definitely not Kansas anymore.
  • mcgivormcgivor Posts: 2,058Solar Expert ✭✭✭✭
    It's easy to make suggestions from the comfort of an armchair so to speak, but perhaps looking into Schneider, not because that's what I use, but because they're an international company, most likely with local company offices and retailers, at least that was my experience in Thailand, the prices were comparable to prices in the US, a Conext 2524 230 was US $1200 locally. Paying large amounts for a repair could exceed the cost of a more professional unit, worth looking into, at very least.
      1500W, 6× Schutten 250W Poly panels , Schneider 150 60 CC, Schneider SW 2524 inverter, 8×T105 GC 24V nominal 

  • EstragonEstragon Posts: 2,609Registered Users ✭✭✭✭
    I wouldn't sink $1200 into a new board, and would instead look for a new inverter better suited to the environment. Outback, for example, makes "sealed" versions of ther inverters which may be less prone to geckos meeting their maker in them.
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • Dave AngeliniDave Angelini Posts: 3,887Solar Expert ✭✭✭✭
    Chuck if you are connecting a battery based inverter to the grid in the tropics you also have to use surge protection on AC and DC.
    I would guess there is a bigger chance of this than anything else causing your problem. I too would start fresh and not try and repair the old one. Save it and see if it can be failure analized by a pro later.
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

Sign In or Register to comment.