How to make a homemade Solar Panel Combiner box

[danielpaulhovan]

This looks just like what I am about to build. Koodos to you for putting it all together and getting yourself off the grid and self-sufficient. I hope you are bathing in your savings. Hopefully the big power company will be sending you a cheque soon !!!

[JustinJJHCS1]

Simple you have the two boxes in Parallel as a result more Wattage for the same Voltage you do this Buy cheap Grid Tied Converters and Wire them in Parallel example 2 120 Watt GTI = 240 Watts total though it is a good Idea to put you DC to DC Charge controller into your Circuit save you burning out your Inverter.

you also have to Parallel connect the AC side too example white to white black to black and green to green

[Klubkid69]

How did you choose the size of your fuse?

[thefaeryman]

Home Depot has a larger 8" by 8" box. It will give room to put longer bus bars in it and combine all panels in the same singular box. then run # 2 or #4 battery/welding cable to your main panel board.

Be sure you ground your negative side of all DC circuits and grounds of devices like inverters to a separate ground rod from your house.

DC has greater voltage drops then AC on same wire, so in this case bigger is better.

Also the neater you can be on wire runs will help you organize power.

[harryflocyberman]

buy your self a bigger inverter 250 isn't enough the company aims makes a great inverter and they are responsibly priced and have great metering and protection features, running a inverter into another inverter isn't a good idea just use one with higher wattage like 5000 watt, instead of super glue use a strain relief like knot the wires or use cable ties inside to prevent accidental pulling, organize your wires into conduit, a rats nest of wires can get out of control.

[ghoku14]

so many boxes,,,

[worldbook17]

super glue is no good for holding electrical lugs and why isnt the size of the wire increasing as it travels through the fire trap combiner boxes lol

[nrodge1]

To be safe you should add a block of plastic that fills the space up to the lid or a small plastic non-conductive box that you might otherwise throw away, between the connector bars. Super glue is not the best at staying stuck if there is any flexing at all, this is outside and takes big temperature swings, expansion etc also wires twisting. If one of the bars comes loose the plastic prevents shorting. Would like to see more, drop by the forums at techluck.com

[markki00]

Prior to 2008 NEC solar installers often made their own combiner boxes but now must install UL approved boxes if used . An 2009 article in Solar Professional magazine clarified options to maintain code compliance. one option to combine to small arrays was to use a HU361 D this provided all necessary protections for shut off and combining. The U stands for non-fused and can be used if your inverter is fused. For more than 2 arrays a UL approved mfg box is needed. Hope this adds to the discussion

[BigBearHuskyMusher]

Hard to tell what's going on . Your wires are everywhere. If you are combining the outputs of both GTI's then of course you will see more watts to the grid. Especially with those 250 GTI's that you will be lucky to get 200 watts top out of each one separately. My 600 watt GTIs are good up to 300W before their efficiencies drop dramatically. With 2 GTIs I get 400 watts total out with 450 input but with just 1 GTI I get 300. Efficiencies will drop as you input more watts. Stay <70% rated input

[skippy3840]

Hey, I have seen these combiner boxes somewhere :)

[highcountrytimber]

To make it cleaner it should all be label and in conduit.

[squirrelbong]

maybe your top inverter is much more efficient?

nice set up.