What is the point of a disconnect before the inverter?

[SurferJon]

Hi, here is my city-approved plan for my upcoming solar setup.

I'm confused about the part I've circled in red. Why do I need that disconnect -- to cut off AC power to the inverter? Can't I just flip the 200 amp switch in the main service panel before it? I've even been told that our city's emergency personnel always just yank out the meter anyway.

After the city inspector leaves, would there be any "conceptual" danger to removing it from the setup? I'm trying to avoid putting another box on the outside of the house, as there's limited space.

 

[Suijkerbuijk]

If the inspection is done with that unit .
And you thake it out than your inspection rapport is not certificate anymore.
Means if by fire the insurance will not pay out if that know you have change it .

Think about that .
Wel here in the Eu.
Do not know in usa or other country's.

 

[Q-Dog]

It looks like they may want a disconnect that can be visibly verified to actually be disconnected. That means they can open the cover and see the contacts are separated. An enclosed circuit breaker doesn't allow that.

 

[kommando]

My breaker is 30M away from the inverter, I have a lockable disconnect next to the inverter as you cannot rely on the breaker not being accidentally switched on as its not lockable and free to access by others.

 

[Q-Dog]

My breaker is 30M away from the inverter, I have a lockable disconnect next to the inverter as you cannot rely on the breaker not being accidentally switched on as its not lockable and free to access by others.

This too!! The ability to lock it in the off position.

 

[SurferJon]

If the inverter is going inside directly behind the meter, can the disconnect go inside as well?

 

[hwy17]

Means if by fire the insurance will not pay out if that know you have change it .

Not true in the US. Fire claims are basically never denied unless it's literally arson. Not that I would support removing it.

 

[Oldphile]

If the inverter is going inside directly behind the meter, can the disconnect go inside as well?

Probably not. My install required an external disconnect. Also, my installer installed a lockable circuit breaker. The utility rejected it. They wanted a knife switch lockable disconnect.

 

[Haysdb]

I have a HUGE metal box the size of my inverter that’s mounted right beside my inverter and inside is…a single breaker as a cutoff switch. lol. I think that huge metal box was all my installer had in his truck.

 

[Q-Dog]

If the inverter is going inside directly behind the meter, can the disconnect go inside as well?

The idea is that emergency personel have to be able to shut it off without going inside.

 

[SurferJon]

The idea is that emergency personel have to be able to shut it off without going inside.

Can't they just shut off the main 200 amp breaker?

 

[740GLE]

Can't they just shut off the main 200 amp breaker?

Does that provide a visual open?

 

[GXMnow]

Can't they just shut off the main 200 amp breaker?

Someone could just as easily turn that 200 amp breaker back on. They want a knife switch that they can lock off.

 

[Q-Dog]

Ask the permit office what options will fulfill their requirements. Or go to an electrical supply house (not a big box store) and ask what they have that meets the specifications on your permit. The supply house deals with this all the time.

 

[GXMnow]

For my Enphase system, they installed (and the city approved) a fairly small Square D 30 amp disconnect switch. The box is just 7 inches wide by 10 inches high. It's not tiny, but it's way smaller than I see on a lot of installs. At 30 amps, it would be fine for up to a 5,800 watt solar power system. And Square D also makes a 60 amp version that is not much bigger. The site says 7.75 inches wide and the same height, so it might be the same box. That would be good for over 10 KW of solar.

 

[SurferJon]

Someone could just as easily turn that 200 amp breaker back on. They want a knife switch that they can lock off.

But the breaker would literally be right next to the inverter.

 

[740GLE]

But the breaker would literally be right next to the inverter.

Try that argument with them.

Heck they could just pull my meter from the meter socket, nothing trumps that, yet they don’t like it.

They seem to like big giant stupid handles mouth breathing firemen can operate, usually with 2-4 different labels/signs telling them what to do.

 

[SurferJon]

It feels beyond paranoid. Even messy. Wish I could understand the reasoning, I feel like I have to be missing something. But feels like the main disconnect / pulling the meter and hitting the RSD button would be more than enough to disable the power.

Surprised they're not accounting for meteors striking the panels.

I'll probably remove the disconnect after the inspectors are gone, unless someone can enlighten me.

 

[Madcodger]

mouth breathing firemen

Really? While they would help you even with that attitude, I hope you never need those "mouth breathers", who are very often taking time away from their friends, families, and "real" jobs to help people who don't appreciate it (like you, it seems). In much of the country, those "mouth breathers" are volunteers who are just trying to help their local community. Many are unpaid, and if they do get a few bucks it's at minimum wage for just the time they spend actually on a call, which might be taking time away from a job or business where they earn much more. It's an often thankless way (as your comment shows) to serve their neighbors and provide a vital service to communities that would otherwise be unprotected. Much of rural America has a frightening shortage of volunteer firefighters. Your comment illustrates a big reason that's the case. Huge risk and a terrible job, done for little or no money, too often for ingrates.

 

[Oldphile]

The AC disconnect is a utility company requirement. I agree that it's unnecessary. The fire department wants the RSD switch.

 

[reader2580]

Fire departments are moving away from pulling meters due to arc flash if the house has a heavy electrical load. My local FD won’t pull meters and waits for the power company to disconnect the power unless they can get to the breaker panel. Breaker panels are inside the house 99% of the time here. The power company usually can get the power off pretty quickly. I don’t know if the new smart meters can remotely disconnect power.

The 2020 NEC requires an emergency disconnect on the exterior of the house for firefighters. It can be locked as firefighters carry means to remove locks.

And, yes, I have a utility required disconnect for my solar. I have no reason to want to remove it post inspection.

 

[740GLE]

Really? While they would help you even with that attitude, I hope you never need those "mouth breathers", who are very often taking time away from their friends, families, and "real" jobs to help people who don't appreciate it (like you, it seems). In much of the country, those "mouth breathers" are volunteers who are just trying to help their local community. Many are unpaid, and if they do get a few bucks it's at minimum wage for just the time they spend actually on a call, which might be taking time away from a job or business where they earn much more. It's an often thankless way (as your comment shows) to serve their neighbors and provide a vital service to communities that would otherwise be unprotected. Much of rural America has a frightening shortage of volunteer firefighters. Your comment illustrates a big reason that's the case. Huge risk and a terrible job, done for little or no money, too often for ingrates.

Calm down, all I’m saying is the requirement for the disconnect is designed for the lowest common denominator.

There are mouth breathers in all industries/professions.

 

[xoxlol]

We have a common answer to all such questions: Job creation.

But in fairness, it might be because of inadequate standards enforced on the inverters themselves... and inadequate standards enforcement with installations - so easier to just mandate something than allow 20 different types of exceptions... and I have seen inverters that caught fire. If that happens, how do you switch it off? Yes, of course, at the mains. But anyways.... back to my initial point.... "its the economy stupid". Aka... "support the economy". Can't afford to? Make something people want, at better quality And then work to get regulations in place mandating it.