Rapid shutdown options

[electrofelon]

Ive dont quite a bit of flat roof PV, but it was before the RS requirements, and since then Ive specialized in ground mount so didnt have to deal with it there either. I have some possible flat ballasted stuff coming up, would someone mind giving me a quick rundown of the options? This is large enough where micros end up just being too expensive so consider those off the table.

We have Tigos, but what do they work and not work with? They dont work with SMA and SMA has their own tigo-like thing correct? So a Tigo would be fine with something like a yaskawa/solectria? Any other options or things to look out for?

Thanks,

 

[ggunn]

Ive dont quite a bit of flat roof PV, but it was before the RS requirements, and since then Ive specialized in ground mount so didnt have to deal with it there either. I have some possible flat ballasted stuff coming up, would someone mind giving me a quick rundown of the options? This is large enough where micros end up just being too expensive so consider those off the table.

We have Tigos, but what do they work and not work with? They dont work with SMA and SMA has their own tigo-like thing correct? So a Tigo would be fine with something like a yaskawa/solectria? Any other options or things to look out for?

Thanks,

Have you considered microinverters or SolarEdge?

 

[electrofelon]

Have you considered microinverters or SolarEdge?

Micro inverters are just too much of a cost premium in my opinion for a system of this size. What do you usually use for your systems in the size range around 100 KW?

 

[jaggedben]

AP Smart is something that was recommended to me but I haven't used yet. Unlike Tigo there's no optimizing or monitoring component to it, so it's cheaper. Not sure how scalable.

I thought SMA was actually using Tigo, i.e. they're interchangeable. But maybe I'm wrong or out of date.

Aside from not liking Solaredge, I don't know why you'd pick Tigo over Solaredge.

 

[electrofelon]

AP Smart is something that was recommended to me but I haven't used yet. Unlike Tigo there's no optimizing or monitoring component to it, so it's cheaper. Not sure how scalable.

I thought SMA was actually using Tigo, i.e. they're interchangeable. But maybe I'm wrong or out of date.

Aside from not liking Solaredge, I don't know why you'd pick Tigo over Solaredge.

Well I admit I am definitely not up to speed on the RS options. Here in New York state we lag behind quite a bit so we weren't even subject to the stuff until recently.

My former partner who is active in RS systems said SMA had their own thing.

 

[ggunn]

AP Smart is something that was recommended to me but I haven't used yet. Unlike Tigo there's no optimizing or monitoring component to it, so it's cheaper. Not sure how scalable.

I thought SMA was actually using Tigo, i.e. they're interchangeable. But maybe I'm wrong or out of date.

Aside from not liking Solaredge, I don't know why you'd pick Tigo over Solaredge.

SMA uses their JMS-4 RSD, which may just be a rebranded Tigo TS4-R-F.

 

[ggunn]

Micro inverters are just too much of a cost premium in my opinion for a system of this size. What do you usually use for your systems in the size range around 100 KW?

We are using SolarEdge for systems that size and larger.

 

[electrofelon]

We are using SolarEdge for systems that size and larger.

Ok wow. Seems like just way too much of a cost adder on larger systems. Looks like micros are about 2.5 times string inverter cost (55 cents/w, 20 cents/w. So lets say we have a 100KW DC system with 85 KW of inverters thats, 17k for string inverters and nearly 47k for micros. Probably some labor savings with micros, but not that much.....

 

[electrofelon]

Ok wow. Seems like just way too much of a cost adder on larger systems. Looks like micros are about 2.5 times string inverter cost (55 cents/w, 20 cents/w. So lets say we have a 100KW DC system with 85 KW of inverters thats, 17k for string inverters and nearly 47k for micros. Probably some labor savings with micros, but not that much.....

Oops sorry, flawed analysis. I didnt include the cost of the Tigos. Also you said solar edge, didnt look at those prices. Ill get back to it later.

 

[BackCountry]

Ive dont quite a bit of flat roof PV, but it was before the RS requirements, and since then Ive specialized in ground mount so didnt have to deal with it there either. I have some possible flat ballasted stuff coming up, would someone mind giving me a quick rundown of the options? This is large enough where micros end up just being too expensive so consider those off the table.

We have Tigos, but what do they work and not work with? They dont work with SMA and SMA has their own tigo-like thing correct? So a Tigo would be fine with something like a yaskawa/solectria? Any other options or things to look out for?

Thanks,

You want to look at PanelClaw, Unirac, Sollega or IronRidge BX. All four are UL3741 certified when used with SMA TriPower inverters. That will allow you to bypass rapid shutdown, no MLPE’s needed. The inverters must be within 1ft of the array boundary, which is pretty easy to do.

UL3741 is a listed assembly (all the way down to what kind of zip ties you can use!). It’ll save you a ton of time and cost.

The code allows two methods (in the new code) to achieve safety, either the typical rapid shutdown MLPE, or UL3741 listed assemblies.

Lots of people like PanelClaw. Unirac is pretty good too, all have options for roof attachment in a hybrid setting.

They also make a nice 4 wire AC cable now you can lay in a wire tray to bypass conduit on the roof for the AC side, route it all to a flat roof recombiner and you’re set.

 

[electrofelon]

You want to look at PanelClaw, Unirac, Sollega or IronRidge BX. All four are UL3741 certified when used with SMA TriPower inverters. That will allow you to bypass rapid shutdown, no MLPE’s needed.

Oh wow that's news to me. Didn't know this was a thing this is new in the 2023 code?

 

[BackCountry]

Oh wow that's news to me. Didn't know this was a thing this is new in the 2023 code?

It’s been in there since the 2017 code cycle, no one had done the testing yet though. Sollega was the first one, PanelClaw shortly thereafter, and the rest just finished.

Is it a TPO or built up roof? Hybrid is usually pretty easy, one or two attachments per X amount of modules pending engineering, so not as many blocks.

Everyone but PanelClaw is some form of plastic hybrid. The composite ones are nice because they come in 100+kw per pallet.

 

[electrofelon]

[QUOTE="BackCountry, post: 2815604, .

UL3741 is a listed assembly (all the way down to what kind of zip ties you can use!). It’ll save you a ton of time and cost.


[/QUOTE]
I did some digging and talked to some people around here. Couldn't find anyone who used 3741 but someone who did price it out and didn't really seem worth it they said. I mean I also complain about RSD, but is adding a $25 Module to the panel really that big a deal?

 

[solarken]

SMA should still work with Tigo TS4's. see https://www.tigoenergy.com/inverter-compatibility?partners=sma
I have installed the SMA branded version of TS4 with the Core1, so I don't have a feel for the pricing of the Tigo currently. It does not seem like there are many distributors that carry them, at least the ones I typically deal with. I would think they are a lot more than $25 each. Probably $33 bucks or more for the TS4-A-F.
I have quoted projects with the Sollega and SMA Core1 combo that meets UL3741 with not RSD, and it seemed pretty attractive to me compared to adding RSD.

 

[ggunn]

SMA should still work with Tigo TS4's. see https://www.tigoenergy.com/inverter-compatibility?partners=sma
I have installed the SMA branded version of TS4 with the Core1, so I don't have a feel for the pricing of the Tigo currently. It does not seem like there are many distributors that carry them, at least the ones I typically deal with. I would think they are a lot more than $25 each. Probably $33 bucks or more for the TS4-A-F.
I have quoted projects with the Sollega and SMA Core1 combo that meets UL3741 with not RSD, and it seemed pretty attractive to me compared to adding RSD.

Be advised that as of a year or so ago, the TS4-A-F is the only Tigo RSD that will play nice with SMA inverters, and at that time they were not easily procured. The SMA JMS-F is (or was) a better choice.

 

[electrofelon]

For a commercial system I would probably be looking at something more along the lines of solectria inverters with AP RSD.

 

[pv_n00b]

Keep in mind that there have been a number of commercial RT systems with fires traced to module-level RSD equipment. I'm pretty skeptical of any RSD only MLPE these days. The DC optimizers seem to be okay.

 

[ggunn]

Keep in mind that there have been a number of commercial RT systems with fires traced to module-level RSD equipment. I'm pretty skeptical of any RSD only MLPE these days. The DC optimizers seem to be okay.

Got links?

 

[pv_n00b]

Got links?

The juicy information is all under NDA and only known to the stakeholders, that's how the PV industry rolls. Information that would help people make safer systems gets locked behind NDAs. The only information that gets to the general public is that a roof fire with a PV system happened.

 

[BackCountry]

[QUOTE="BackCountry, post: 2815604, .

UL3741 is a listed assembly (all the way down to what kind of zip ties you can use!). It’ll save you a ton of time and cost.

I did some digging and talked to some people around here. Couldn't find anyone who used 3741 but someone who did price it out and didn't really seem worth it they said. I mean I also complain about RSD, but is adding a $25 Module to the panel really that big a deal?[/QUOTE]

Help me understand that one? There’s nothing to it other than using a listed racking and inverter combo.

Should save you the entire material and labor cost associated with RSD MLPE’s.

Real numbers for a project we’re on:

Using a listed assembly (in this case, PanelClaw) the racking cost is the same as any other racking option we have (ballasts) and we don’t have a single MLPE, all we have to do is locate the inverter within 1ft of the array boundary, which we would do anyway.