Whole home back up - a simple approach

[v2h8484]

In case anyone is wondering what's involved in the setup of a ground rod with proper GEC for a generator.

Sponsored

 

[TaxmanHog]

 

[Henry Ford]

No disrespect but your "proxy" sounds a like mental crutch for skipping critical thinking. The problem with mental crutches is that they are prone to hacks. Case in point, the neutral transfer switch without a separate EGC setup somehow got labeled as code compliant (the "hack") on this forum and I suspect that got most people to quickly but incorrectly think it's "safe". If something (e.g. safety) is important then it's best not to rely on mental crutches.

When you say "no disrespect" and immediately say something disrespectful you are still being disrespectful.

In the context of talking about electrical setups on the internet, code is a good proxy for safety. In the context of talking about electrical setups over beers, my thoughts are more nuanced.

What exactly is your goal here? You've changed my mind, I completely agree with you. I don't see how the above post is helpful.

 

[v2h8484]

When you say "no disrespect" and immediately say something disrespectful you are still being disrespectful.

In the context of talking about electrical setups on the internet, code is a good proxy for safety. In the context of talking about electrical setups over beers, my thoughts are more nuanced.

What exactly is your goal here? You've changed my mind, I completely agree with you. I don't see how the above post is helpful.

Sorry for any offense. None intended. My comment is simply a reminder about the general over-reliance on simplistic notions that can be misapplied and lead otherwise thoughtful people to jump to incorrect conclusions. One thing I would add is that I was one of the people in this case. A motivation for the comment came from the fact that I had known about SDS requirements and yet I failed to recognize their relevance here for a long time.

 

[Henry Ford]

Sorry for any offense. None intended. My comment is simply a reminder about the general over-reliance on simplistic notions that can be misapplied and lead otherwise thoughtful people to jump to incorrect conclusions. One thing I would add is that I was one of the people in this case. A motivation for the comment came from the fact that I had known about SDS requirements and yet I failed to recognize their relevance here for a long time.

I'll add that code is extremely hard to read so people - I, specifically - turn to the Cliff's Notes version available on YouTube and internet forums. I digress.

Here's a question for someone with more knowledge about electrical systems and safety than me. In a Lightning/Generac setup, what does grounding at the truck protect against that the truck's GFCI and the home's grounding rod don't already protect against?

 

[Runaway Tractor]

Tested using the truck to power up the house through my generator inlet. Success mostly. Unable to handle the startup surge of the heat pump compressor and the Pro Power trips off on overload protection. In order to use the heat pump (normal central heating and cooling), I'll need to put a soft-start unit on the compressor ($379).

This becomes even easier if I run some 8-8-8-4 aluminum SER around to the garage to put the generator inlet box in the garage. Warm, dry, and plug it right in.

 

[Maquis]

I'll add that code is extremely hard to read so people - I, specifically - turn to the Cliff's Notes version available on YouTube and internet forums. I digress.

Here's a question for someone with more knowledge about electrical systems and safety than me. In a Lightning/Generac setup, what does grounding at the truck protect against that the truck's GFCI and the home's grounding rod don't already protect against?

The only thing that “grounding”, as in connection to earth protects against is lightning strikes (and that is iffy).
The purpose of the ground wire (EGC) run with each circuit is to clear a fault (trip the breaker) in the event a “hot“ wire comes in to contact with something metallic that it shouldn’t. In simplest terms, proper “grounding” ensures that any metal on an electrically-powered device trips the breaker before it shocks you. This capability exists because the neutral and ground wires are bonded at the panel, not because of some magic connection to dirt.

 

[v2h8484]

I'll add that code is extremely hard to read so people - I, specifically - turn to the Cliff's Notes version available on YouTube and internet forums. I digress.

Another thing that led me astray is the fact that I have seen several forum posts about electrician installed neutral transfer switch (e.g. Generac 6852) and they didn't mention the SDS requirements. However, the Generac manual (p7) clearly states the requirements:

https://www.generac.com/generaccorp...s/homelink-owner-s-manual.pdf?ext=.pdf#page=9

Makes one wonder how well electricians really know about code requirements for generators.

 

[Henry Ford]

The only thing that “grounding”, as in connection to earth protects against is lightning strikes (and that is iffy).

That was my understanding as well. Is equipment attached to a Lightning through a Generac 6852 not protected from lightning via the dwelling ground (to earth)? Every part of the system is connected to same grounding system it was connected to before it was switched to generator power.

The purpose of the ground wire (EGC) run with each circuit is to clear a fault (trip the breaker) in the event a “hot“ wire comes in to contact with something metallic that it shouldn’t. In simplest terms, proper “grounding” ensures that any metal on an electrically-powered device trips the breaker before it shocks you. This capability exists because the neutral and ground wires are bonded at the panel, not because of some magic connection to dirt.

This is precisely the protection that is preserved when switching neutrals in the Generac 6852 is it not? In my case more so because I don't have any GFCI protection in my home panel.

As I mentioned before, I'm not an electrician so it's possible I'm missing an important point.

 

[Howard_Scott_Warshaw]

Interters have batteries, so they form a grid themselves, while isolated from utility

Correct. There's a auto-transformer in the SolarEdge BUI that forms the grid for the SE inverters to then sync with. Since you have whole home backup, that would suggest the truck and the SE system were not isolated from each other, which means the inverter in the truck tried (and did?) sync with the microgrid. Was it successful or did one of the devices throw an error?

 

[Johnif]

Correct. There's a auto-transformer in the SolarEdge BUI that forms the grid for the SE inverters to then sync with. Since you have whole home backup, that would suggest the truck and the SE system were not isolated from each other, which means the inverter in the truck tried (and did?) sync with the microgrid. Was it successful or did one of the devices throw an error?

Nope both systems operated well, once utility was switched off

 

[Texas Dan]

I just watched a video for the installation of the Generac 6852 transfer switch and could not believe what I saw. At approximately 6:35 minutes into the video I the guy started connecting the load neutrals into the main panel neutral bar right after he connected the main transfer switch neutral into the EXACT SAME BAR! We really need to be careful about what we believe from the internet.

 

[GDN]

Tomorrow is test day. 40' 30 amp cord, dog bone from 30 amp to male 14-50, going to plug into my 14-50 outlet that I used to use with a Tesla mobile charger.

I know - this way is dangerous. This is a test. I'll shut the house main off first. Plug the cable in to the wall, then the truck, then power on Pro Power.

I've got to spend an hour or two mapping the part of my panel that isn't mapped exactly. Then I'm going to use the truck, one circuit at a time to find whot each of the fridges, freezers and lights pulls. Then I'll see if it will run the pool pump and last the AC. I'm 99% sure the AC is a no.

If all works, I'll get a generator plug and the lock out for the panel and go from there.

 

[hturnerfamily]

I've done all this with my same NEMA 14-50 outlet serving as the 'inlet' for power from the TRUCK, and, as I've shown on youtube links, it all works just fine. No, everyone will not do it this way, but I've proved that it works if you want it to...

 

[GDN]

I've read through many threads and approaches to this. I've seen a couple of videos early on with how much can be powered from the truck, but the question is, can you or should you expect 30 amp continuous use from the truck? Its rated at 30, we use 30 amp rated cables, but should we only expect or push it to the 80% of that value for continuous use?

Sponsored