How many of you DIY have panels on your house roof with no Rapid Shutdown?

[SoFar]

I would like to know if a lot of people actually have solar panels on their "city" home roof without optimizers or rapid shutdown for the panels?

I would like to install 10 panels with an 3000W All-in-One inverter not tied into my existing home wiring. I would use it to power with an extension cord or seperate panel not tied to exsting wiring.

 

[chrisski]

For the thing like that I’m thinking of making, there would be a rapid shutdown. Not sure its code, It’s really needed for the same reason that if the house is on fire the fire department can shut this down quickly regardless of whether or not its grid tied.

I am thinking of something like that to run an outlet in the garage. I would not use an extension cord but run the wires through conduit until it reaches the inverter and then hard wire the inverter and run that wire through conduit.

The purpose of this contraption would be to run Level 1 EV charging at 1500 watts for hours on end when the sun is shining.

 

[wattmatters]

Define what you mean by rapid shutdown.

Are you talking about module level power electronics, or DC isolators?

 

[45North]

My new A/C has a master on/off switch on the outside of the house as per code.
Seems to me this would be a good idea for all PV systems too, whether they are required where you live or not.

 

[wattmatters]

In Australia DC isolators are required on string systems. MLPE is not.

The code in the USA requiring MLPE seems to me to be more of a protection racket for micro inverters and optimisers than a real safety feature. Modern string inverter systems come with Arc Fault Circuit Interruption as well as solid installation standards.

My grid tied system doesn't have AFCI but has DC isolators (as required and sensible) next to the inverter as well as on the roof (which is dumb but thems the regs - which have changed recently).

My off-grid garage PV has a DC isolator near the inverter. There is also a combiner/breaker box inside the garage for myself to use but less obvious than the wall mounted DC isolator.

 

[SoFar]

Define what you mean by rapid shutdown.

Are you talking about module level power electronics, or DC isolators?

Rapid Shutdown or a way to turn off power from solar array like MLPE. I would like to a purchase a All-In-One Inverter (Growatt, MPP or EP4) and use it with a few used solar panels i have. However, I would like to be able to shut the power down from the array in an emergency. Whether or not it's through Rapid Shutdown (which I don't think will work with an AIO), or Optimizers or micro inverters, I don't care. I haven't really seen that it can be done effectively with the AIO I'm looking at.

 

[Eclipse]

Trying to look into rapid shut down devices now. I will be using an AIO inverter and 11Kw on my roof (installing myself). Per NEC, need RSD for the pv array, but it’s pretty hard researching for DIY off grip applications. At this point in time, I’m pretty confused on what hardware I need and how it’s installed.

I’m honestly surprised there isn’t more discussion about it in this forum with the amount of people doing solar. Unless many just aren’t installing it. Seems like everything I’m finding if more complicated that I need.

 

[Mike 134]

In Australia DC isolators are required on string systems. MLPE is not.

The code in the USA requiring MLPE seems to me to be more of a protection racket for micro inverters and optimisers than a real safety feature. Modern string inverter systems come with Arc Fault Circuit Interruption as well as solid installation standards.

My grid tied system doesn't have AFCI but has DC isolators (as required and sensible) next to the inverter as well as on the roof (which is dumb but thems the regs - which have changed recently).

USA wants panel level shutdown, so firefighters are not exposed to more than 30volts. Just imagine having to ventilate a roof, 30 feet off the ground, water everywhere, you're wrestling with a chainsaw and a string of panels has 400volts DC in the exposed wiring right next to you. THAT is why the rapid shutdown rule exists.

 

[Hedges]

10 panels ...
I used to have 24 panels, 6 series groups of 4 panels joined through a 6 pole "segmenting" breaker. When breaker was open, each group of four "12V" panels was in series, about 85Voc. With the ganged breaker closed, all 6 groups were in series for about 510 Voc.

Such a breaker setup, located within prescribed distance of panels or possibly wired inside conduit, should comply with < 80V within array and < 30V outside array. Maybe extension handle to trip breakers from the ground, or situate panels down to the eaves to facilitate.

 

[chess-equality]

Requesting you guys if you could please add some links here about products (rapid shutdown, MPLE, etc.) that you are looking into.

I don't use PV yet but I have inverter/charger + battery banks and will be looking to PV in the future.

Thanks!

 

[wattmatters]

USA wants panel level shutdown, so firefighters are not exposed to more than 30volts.

Australian firefighters are consulted on PV array standards here too.

Indeed the most recent standards here have removed the requirement for rooftop DC isolators, provided other cabling standards are met. Reason: biggest cause of solar PV fires are failing rooftop DC isolators which the fire fighters originally insisted on.

This rush to rooftop ventilation by firefighters seems to be a perculiarly US thing. It’s a far less common strategy here and in Europe.

https://www.cfbt-us.com/pdfs/VentilationStrategies.pdf

 

[jasonhc73]

I have a DC switch. An open circuit created by a DC switch can't be more rapid when switched open.