To ground, or not to ground

[steadfast]

Some details: I'm planning on hooking up...

• x2 100ah 12v lifepo4 batteries
• 40a mppt solar charge controller (w/ 40a fuse)
• x4 100w solar panels
• 2000w renogy inverter (w/200a fuse)
All on a plywood.

All to power phone, small electronics, x2 8w light bulbs with ac plugs, and a 500w air conditioner (summer) or 500w heater (winter). Reason for the 2000w is just for random high power devices. Ex: hair dryer 1500w

I currently use an ecoflow delta (not lifepo4).
I'd rather just diy a solar system with lifepo4 to have longer life cycles and if anything i can replace the batteries unlike an ecoflow where batteries are not replacable.

It's for a lifetime 15x8 shed so its not connected to house, electrical, plumbing etc. Completely off grid.

Shed is sitting on top of wood floor frame. All concrete around me. About 20ft away from house.

Question: Do i need a ground? If so HOW and WHERE do i ground the inverter and the mppt controller. I've searched for days and got random answers. Same with videos. Most say to ground to home but im not using it near the house.

One diy video the guy didn't ground it at all. Other video of will diy 400w system grounded it to the fusebox buss bar but im not using a fusebox as everything im using will be through the inverter outlet. Then others say grounding is a myth.

I'm in Los angeles, so we dont get much lightning.

I just want to know where to ground or if i even need to.

This grounding is whats confusing me the most.

Thank you in advance to anyone who responds.

 

[niktak11]

Put in two ground rods outside the shed at least 6ft apart and connect to those

 

[pollenface]

What if the inverter is in a caravan?

 

[pvgirl]

You'll want to ground. First you will want to bond your system together, that is connect all the metal parts of you system together. If you don't have main electrical panel pick on location to run all your grounds to. You'll want to bond the solar panels, batteries if metal, charge controller, and inverters together with ground wires run to your main grounding point. Second you will want a system ground, one location where neutral and ground are bonded together, your inverter may provide this, but verify with an outlet tester or multimeter. Otherwise you will need to create this bond either at main electrical or with a generator ground bond plug in an outlet. Last you will want a ground electrode system, 2 ground rods outside connected together, and run to your main ground point of the system in this shed.

 

[mikefitz]

What if the inverter is in a caravan?

What if the inverter is in an aircraft?

What if the inverter is in a boat?

In such applications you cannot connect to earth rods.

 

[steadfast]

Some details: I'm planning on hooking up...

• x2 100ah 12v lifepo4 batteries
• 40a mppt solar charge controller (w/ 40a fuse)
• x4 100w solar panels
• 2000w renogy inverter (w/200a fuse)
All on a plywood.

All to power phone, small electronics, x2 8w light bulbs with ac plugs, and a 500w air conditioner (summer) or 500w heater (winter). Reason for the 2000w is just for random high power devices. Ex: hair dryer 1500w

I currently use an ecoflow delta (not lifepo4).
I'd rather just diy a solar system with lifepo4 to have longer life cycles and if anything i can replace the batteries unlike an ecoflow where batteries are not replacable.

It's for a lifetime 15x8 shed so its not connected to house, electrical, plumbing etc. Completely off grid.

Shed is sitting on top of wood floor frame. All concrete around me. About 20ft away from house.

Question: Do i need a ground? If so HOW and WHERE do i ground the inverter and the mppt controller. I've searched for days and got random answers. Same with videos. Most say to ground to home but im not using it near the house.

One diy video the guy didn't ground it at all. Other video of will diy 400w system grounded it to the fusebox buss bar but im not using a fusebox as everything im using will be through the inverter outlet. Then others say grounding is a myth.

I'm in Los angeles, so we dont get much lightning.

I just want to know where to ground or if i even need to.

This grounding is whats confusing me the most.

Thank you in advance to anyone who responds.

Also to add theres about 4 ft of thick concrete under the shed so drilling will be tough. Even then runor has it by a neighbor that there is a wrecked car under this same concrete God knows what else is burried under here. No access to earth ground whatsoever. Everything is concrete around the shed and below. Thats whats making this grounding difficult. To a point i ask is grounding even necessary for what im building.

 

[pvgirl]

Also to add theres about 4 ft of thick concrete under the shed so drilling will be tough. Even then runor has it by a neighbor that there is a wrecked car under this same concrete God knows what else is burried under here. No access to earth ground whatsoever. Everything is concrete around the shed and below. Thats whats making this grounding difficult. To a point i ask is grounding even necessary for what im building.

There’s still value in bonding the metal parts of your system together, and insuring you have a neutral/ground bond, even if you can’t get an earth ground. This will ensure circuit breakers and other protection will have the reference to work properly and keep things safe.

 

[timselectric]

Question: Do i need a ground? If so HOW and WHERE do i ground the inverter and the mppt controller. I've searched for days and got random answers.

A grounding system is created by, and begins at the N/G bond.
It sounds like you are using a small "portable" inverter?
It may not be capable of dealing with a N/G bond. (Some can be damaged)
You will have to check with the manufacturer for this information.
If not, then you can't ground your system.
I can't make any further recommendations, until you find out this information.

 

[Zwy]

Question: Do i need a ground? If so HOW and WHERE do i ground the inverter and the mppt controller. I've searched for days and got random answers. Same with videos. Most say to ground to home but im not using it near the house.

im not using a fusebox as everything im using will be through the inverter outlet.

Some of these inverters have a grounding lug on the outside case. This is bonded to metal surfaces that could be possibly energized in a ground fault situation.

Internally, these are bonded case to neutral. Usually these are used as a floating system with no connection to earth, for example an RV. However all metal surfaces should be bonded to the case.

I have a similar inverter in the back of the cab in my truck that carries the truck camper. Mine is hardwired but concepts are still the same. With the hardwire, there are 2 current carrying conductors, the L and N. The third terminal is for an EGC. Your inverter will be wired the same only it has an outlet.

No earthing ground is needed as the inverter is source and as long as the case is bonded internally and you bond all metal that could be energized to the case, any ground fault will trip the internal overload protection. This is the same as installing an inverter in an RV, it is a floating system.

Now, having said all that, there still is static electricity created by natural forces. If this is a stationary installation, you could install a earthing ground but it isn't necessary.

 

[mikefitz]

Not all Renogy inverters have the neutral to protective earth conductor bond, thus any earth leakage device, GFCI, to protect persons will not function. For a 'portable' application where an appliance is plugged into the inverter directly there is minimal risk and everything can float. As soon as you have a 'permanent' install with multiple appliances and distributed AC wiring, the risk is greatly increased and the inverter needs to be a type with neutral to earth bond, ( or a type that can be configured so), and GFCI, (RCD in Europe) for protection against electric shock installed.
In an insulated shed, installing earth rods to provide a reference earth is a good idea. Metal body in a vehicle is the earth