New Solar Installation & Issues

craigtone
craigtone Registered Users Posts: 2
in Caravan, Recreational Vehicle, and Marine Power Systems #1
Hello! I finally bit the bullet and purchased an RV off-grid solar kit for our camper. The camper is parked on our getaway property and not used to travel. The kit is a single 100W PV on a 45 degree stand, 10A 12V charge controller, 110AH deep-cycle lead acid, 1500W MSW inverter. PV wire is fused 12AWG and about 10', fused 12AWG to battery is about 1', fused 2AWG to inverter is 1'. 12AWG romex through the camper to the various receptacles and circuit breaker box. We are only really trying to run a 4.1 cu. ft. refrigerator on AC. The trial run was last weekend and it did not go so well! The fridge started but then stopped. I unplugged it and plugged it back in then it ran again. There were several times I had to do this. One evening the battery was too low before the sun started charging. I have another 90AH I can put in parallel to resolve that. Then Sunday we went for a walk and came back to a fried inverter! The inverter is supposed to have under voltage, over voltage and overload protection. I opened it up to see if the fuse was blown and the circuit board is black and fried. The replacement inverter (covered under warranty) is on it's way.

So did I just get a bad inverter or am I doing something wrong? When the fridge was running the inverter showed about 92W load on the digital display. I brought the fridge home and plugged it in here at the house and it works fine.

Everything else in the camper is run off of DC except for the occasional iPhone charger or wall wart for the Big Buddy heater fan.

I am hoping to get this all figured out so I can fix everything on my next trip up and prepare the camper for hunting season. Since I installed an AC fridge I also plan to close off the roof fridge vent and air intakes to keep out the draft.
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Comments

  • waynefromnscanada
    waynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    #2
    Hi "craigtone", welcome to the forum.
    First impressions looking over your post - - -
    Although you haven't listed the combined, total daily (24 hour) consumption in KWH of all your electrical loads and what you need, like to, or wish to operate on your off grid system, just that fridge alone is a HUGE load for one little 100 watt panel.
    A single 110AH or even two is extremely small for your loads listed, and a 1500 watt inverter is huge for such a small system. Inverters consume power just to keep running, and generally the bigger the inverter, the bigger the load on the batteries just to keep it running.
    And then there's the fridge - - - all too often small fridges are energy pigs, gulping down as much or more than a new, full sized, high energy efficient fridge.
    Then there's the draining of your battery and later adding another.
    I suggest you start doing a lot of research and reading on this forum first, then with help from some of our learned friends here, start from scratch and do it right. If that is, you want to have a reliable and satisfying system that won't have a very short life or let you down when you need it most.
    Generally one starts by knowing the total daily (24 hour day) consumption of ALL your combined loads. Then decide how many days you need to run it during times of no sun, 2 days? 3 days? This is used to determine the required size of your battery bank. FINALLY comes the size of the solar panel array in watts, required to power your daytime loads PLUS properly recharge your battery bank to have it ready for the coming night or days without sun.
    OH, and back to the batteries for a moment - - - even "Deep Cycle" lead-acid batteries should never be discharged dead. To do so will very shortly end their life. Aim for taking only the top 20% of power from them, leaving 80% in reserve. You can occasionally take them down to 50 % if you must, but even that will shorten their life.
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  • westbranch
    westbranch Solar Expert Posts: 5,183 ✭✭✭✭
    #3
    MSW can be hard on some motors... search here for MSW as there has been lots of discussion... it can be model specific too... Best to look into a TSW/PSW inverter to keep most electronics happy...
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
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  • craigtone
    craigtone Registered Users Posts: 2
    #4
    This is just a 24' camper semi-permanently parked on our hunting/camping/recreational property. We use it for weekend trips. The only energy consumption is the fridge at 92W and assuming 12hrs a day (50% D/C) that is about 1100WH. The only other things are 12VDC lights in the camper and a range hood that we typically only use for breakfast.

    Also, the camper is just a temporary solution until we build an off-grid cabin on the property. At that time I will do a wish list, load charts, etc. to calculate PV needs, battery bank requirements, etc. The plan is 100% solar with all 120V wiring with LED bulbs and Energy Efficient appliances, rainwater catchment/greywater, composting toilet, etc.

    For now I just need to keep the fridge running for weekend trips ... possibly extended weekend trips (4 days). The batteries stay at the camper so are constantly being topped-off when not at the property. This also brings another question about the winter. Will the constant charge be enough to keep them warm enough to stay hooked-up over winter?

    I did research the MSW vs. PSW and everyone argues about it. The manufacturer says there should not be a prob. The fridge is this one if that helps (it is Energy Star, non auto-defrost, etc.): http://www.amazon.com/gp/product/B00MPZS3UC

    As for the inverter, it was part of a package deal with the panel, wiring, bracket, controller, etc. from what I thought was a reputable online company ... I am now thinking otherwise ... DOH!

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