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Why and how grounding is needed for Inverters

Hi,

I have a very noisy mains line. When my amp(s) are plugged directly into the wall efficient headphones like Focal Utopia sound like a modem from old days. It sounds like data transfer is happening. I tried diagnosing the problem by demoing smaller inverters like ones from Duracell(500Wh) and Ecoflow Delta(1200Wh). They did alleviate the problem, but the issue with them is when in charging mode their fan is constantly on. They are not really loud but distracting.

I am thinking of this particular Renogy Model inverter . My power requirements are really meager - 50W for my headphone amp and 75W for my Holo May Dac. Add maybe another 100-150W for future. So the inverter is kind of overkill but seems cheaper than most audiophile solution. When listening I'll run off the battery and other times it will be charging from the wall.

What I am confused about is grounding in that particular inverter. I am planning on keeping the inverter in my listening room in some corner. There are no children so no one should be going and touching it.  What I am not sure about - is grounding needed in this inverter ? If so how do I do it?  My mental model is - Use the inverter/charger + 12V LiFe battery + DC breaker + DC switch + 3 Pin cable to connect to the charger to wall plug + Modify a power strip and hook that directly to the inverter. Then plug in my Amp and Dac to the power strip. Is there any further explicit grounding needed? If so, where and why?

 

Thanks.

neo_the_one
jea48
4,785 posts
 

@neo_the_one,

I took the time this morning to look up the unit, I believe, you are buying. Its wiring scheme is different than the 3000W unit video above.

Here is the manual for this 2000W unit. (Click on the Link below.)

https://www.renogy.com/content/RNG-INVT-2000-12V-P2/INVT-P2-Manual.pdf

Page 8 shows a ground lug (4)

Page 11.

Grounding
The Renogy Pure Sine Wave inverters come equipped with a grounding lug to appropriately ground to earth or to another designated ground (for example, a metal frame of an RV). The connections to ground must be tight and against bare metal. Whether using the inverter in a
mobile application, such as an RV, or in a building, grounding is highly recommended. The recommended wire size for grounding is 10 AWG insulated copper strand wire. For more
information regarding grounding, users and/or installers must consult with the Local and National Electric Codes (NEC) for more specific grounding regulations and suggestions as they can change per scenario.

This applies for your situation.

Local and National Electric Codes (NEC) for more specific grounding regulations and suggestions as they can change per scenario.

Do not run the #10awg ground wire to a dedicated outdoors ground rod. The ground wire needs to connect the electrical service grounding system of your house.

Where to connect the #10awg ground wire? I would need more information.

 

.

 

neo_the_one OP
21 posts
 

Hi @jea48 ,

The manual you have shared above is for a different inverter ONLY model. The one I posted above is inverter and charger model. Both are 2000W models.

The model you have posted is the one that got me confused. It does have a separate grounding post that the inverter + charger does not seem to have.

I could not find anything related to grounding in the invert + charge model's manual 

jea48
4,785 posts
 

@neo_the_one

The model you have posted is the one that got me confused. It does have a separate grounding post that the inverter + charger does not seem to have.

I could not find anything related to grounding in the invert + charge model’s manual

Look at page 13 in the manual.

The picture shows the safety equipment ground as part of the AC power in wiring. If the unit will be plugged into a wall outlet the safety equipment grounding conductor of the in wall branch circuit wiring is used. The terminal strip on the unit shows where to land, terminate, the ground wire from the power cord.

 

The video shown on the page is for the 3oooW unit. Apparently the only difference between the 2000W and 3000W is the FLA rating...

.

neo_the_one OP
21 posts
 

@jea48 Thanks for confirming.

4krowme's avatar
4krowme
542 posts
 

@jea48 is one of the very few here that I trust with information about AC electrical. I have seen responses from others in other threads that seem to have authority until pressed for actual facts. I am glad that we have few people here who understand these electrical circuits well enough to point us in a safe direction.

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