Earth Grounding Questions (and many more) for a small off-grid system.

[Sunking]

For sure that inverter would have to go directly to battery fuse. His fuse block is rated 100 amps max with 10-32 studs, each at 30a rating

Yeah I was pretty sure blade fuses only go up to 30 amps.

[inetdog]

Well I feel vindicated now that you posted the link for all top see. If you read the article you should have picked up Jeff was reluctant to do this and only did so from pressure from the editors. So hopefully now you understand my reluctance.

I also notice that Jeff's article did not differentiate between GEL and ATM sealed batteries for this use. Any idea why? Low enough charge and discharge rate that GEL could handle it, or an insertion during editing?

[FloridaSun]

Yeah I was pretty sure blade fuses only go up to 30 amps.

fuses aside.. I'm surprised you haven't said anything about using a 1750W inverter with 200Ah battery...... Seems a bit too much inverter to me.

[Sunking]

I also notice that Jeff's article did not differentiate between GEL and ATM sealed batteries for this use. Any idea why?

No not really. If I had to guess just an oversight, or he did not want to get into that for fear from battery manufacture advertisers. When you are writing for a sponsored media, you have to be careful about what you say (censor) as to not upset your sponsors. Or a remote chance he is not aware of Gel battery limitations. In 2008 when that was written, there were not a lot of choices for batteries in RE applications. It has only been th elast couple of years manufactures responded to demand. Note he said golf cart batteries or RV/Marine batteries. Both of those are Hybrid and no real true deep cycle readily available then.


Who knows. Have not talked to Jeff in quite a while, but if I can remember I will ask next time I chat with him. Have not seen him since I left the NEC code making panel.

[CanadianCabinSolar]

OK you owe me big time. Ask anyone here, I do not do this type of thing.

For the MRBF fuse to CC = 30 amp using # 8 AWG
For the MRBF to Fuse Panel = 200 Amp using no less than 2 AWG

You also have a problem with your wire gauge from Fuse Panel to Inverter Input. A 1750 watt 12 volt inverter will take 145 amps at full power. That will require #4 AWG. Personally I would not connect the inverter to the fuse block. I would connect both positive and negative directly to the battery post using a second single battery MRBF Battery fuse (150 amp) which is not shown in the drawing. I do not think you can find a 150 amp blade fuse for the fuse panel.

Thanks for all your advice.
I have ordered the two terminal fuse blocks and three fuses in the sizes you specified ( man, I love amazon ).

Thanks again.

[CanadianCabinSolar]

fuses aside.. I'm surprised you haven't said anything about using a 1750W inverter with 200Ah battery...... Seems a bit too much inverter to me.

I was worried about that, but the inverter will generally only be used to power a 19 inch LED TV and media player. I just wanted to have more power if I needed it on the rare occasion.

[CanadianCabinSolar]

fuses aside.. I'm surprised you haven't said anything about using a 1750W inverter with 200Ah battery...... Seems a bit too much inverter to me.

Should I downsize my inverter?

[FloridaSun]

I was worried about that, but the inverter will generally only be used to power a 19 inch LED TV and media player. I just wanted to have more power if I needed it on the rare occasion.

Rare very short occasion.

[FloridaSun]

Should I downsize my inverter?

Might be more efficient. Save a bit on wiring too.

[Sunking]

Should I downsize my inverter?

I would. I noticed it earlier but just ignored it. You want to run the smallest inverter you possible can. Try to add up any likely devices to be on at the same time. Say that number is 400 watts. Multiply that number by 1.5. So in this example 600 watts.

Another good approach is to use two inverters. One small for the every day stuff, and a larger one for those rare occasions you need it. Keep the large one turned off until needed.

[Mike90250]

OK you owe me big time. Ask anyone here, I do not do this type of thing.
For the MRBF fuse to CC = 30 amp using # 8 AWG
For the MRBF to Fuse Panel = 200 Amp using no less than 2 AWG
..

Calculated answers with results . Schematic .

Someone must have hacked Sunkings account

[Sunking]

Calculated answers with results . Schematic .

Someone must have hacked Sunkings account

Yeah that is a $500 answer huh?

[CanadianCabinSolar]

Yeah that is a $500 answer huh?

The check is in the mail Sunking!
Could I push my luck and ask one more question?
Is it ok for me to use a generator and battery charger to bring my batteries back up? I have an intelligent battery charger which is safe for AGM batteries. Can I just attach the charger while everything else (charge controller, inverter and 12 Volt panel) is attached?

[Sunking]

The check is in the mail Sunking!
Could I push my luck and ask one more question?
Is it ok for me to use a generator and battery charger to bring my batteries back up? I have an intelligent battery charger which is safe for AGM batteries. Can I just attach the charger while everything else (charge controller, inverter and 12 Volt panel) is attached?

Absolutely.

[CanadianCabinSolar]

Absolutely.

I can't thank you enough.
Thanks for all your help and advice.