Tell me about SolArk.

Haugen

Tron God
When is inspection? How did you handle rapid shutdown in the end?
The inspection was last Tuesday morning. I walked around with him and then left for a 4 day hunt on an island. Just now catching back up.

Since the code didn't require the RSD, I took advantage of not having them installed. I need to get them back out to connect the loads and turn it on.

I have started the net-metering process.

Today, I brought the batteries out to the cabinet. I need to add compression and bus bars, so there is some work for me to do as well.
20201127_120917.jpg
 

svetz

Works in theory! Practice? That's something else
Is all of Florida able to skip RSD?
RSD is NEC, so AFAIK unless you're a ground mount it should be required everywhere. Possibly the county hasn't adopted NEC 2014 yet or it doesn't apply for some other reason?
 

coolwaterxii

Solar Enthusiast
The inspection was last Tuesday morning. I walked around with him and then left for a 4 day hunt on an island. Just now catching back up.

Since the code didn't require the RSD, I took advantage of not having them installed. I need to get them back out to connect the loads and turn it on.

I have started the net-metering process.

Today, I brought the batteries out to the cabinet. I need to add compression and bus bars, so there is some work for me to do as well.
View attachment 28717
How's the progress of your battery bank? I'm curious what BMS you end up using. Thanks!
 

solardad

Solar Addict
RSD is NEC, so AFAIK unless you're a ground mount it should be required everywhere. Possibly the county hasn't adopted NEC 2014 yet or it doesn't apply for some other reason?
..or based on the purview of the local inspector. In our area the local inspector can make adjustments ad-hoc to the code / compliance.
 

Haugen

Tron God
RSD is NEC, so AFAIK unless you're a ground mount it should be required everywhere. Possibly the county hasn't adopted NEC 2014 yet or it doesn't apply for some other reason?
My jurisdiction has not adopted NEC 2014, so no RSD required. I considered pushing the issue and having them install them, but I knew the system would be grandfathered and by the time I do anything to be required to meet the new code, the RSDs would need to be replaced anyway. There is a cutoff for the PV by the main service panel.
 

solardad

Solar Addict
My jurisdiction has not adopted NEC 2014, so no RSD required. I considered pushing the issue and having them install them, but I knew the system would be grandfathered and by the time I do anything to be required to meet the new code, the RSDs would need to be replaced anyway. There is a cutoff for the PV by the main service panel.
Be careful what you wish WRT RSD there is a push by installers to revert back pre RSD due to ongoing safety issues being discovered.


Video explaining the issue
 

ArthurEld

Photon Sorcerer
I'm in Florida too. I did string level rapid shut down.
The inspector didn't know what it was. I probably could have gotten away without it too.
String level RSD doesn't cost much anyway.
 

Hedges

I See Electromagnetic Fields!
Be careful what you wish WRT RSD there is a push by installers to revert back pre RSD due to ongoing safety issues being discovered.


If the problem is MC connectors failing and burning up, I don't think cutting the number of connectors in half (by eliminating RSD modules, or integrating them in junction box) is particularly useful. That only cuts the number of house fires in half.
If MC connectors are failing, I think their failure rate should be reduced by a factor of 100.

And then, AFCI should be 100% effective in preventing an arc from continuing long enough to start a fire.


"Adding electronics on the roof — which means more noise on the DC line, which affects arc fault detection and compromises the reliability of the shutdown function in the first place"
RSD have to be quiet enough to not cause false tripping of AFCI.
Performance of AFCI vary widely between implementations.

"More specifically, under 80VDC AFCI is not required despite the fact that 40VDC and lower can easily cause a arc."
Sounds like microinverters ought to implement AFCI.
 

GXMnow

Photon Sorcerer
In my opinion, these installers want to get rid of RSD to not have to take the time to install it and have their poorly done connections fail.
 

solardad

Solar Addict
If the problem is MC connectors failing and burning up, I don't think cutting the number of connectors in half (by eliminating RSD modules, or integrating them in junction box) is particularly useful. That only cuts the number of house fires in half.

Really..? I am all for safety and would rather reduce any chance of a system failure or fire. Reducing the number 'moving pieces' tends to extend the overall performance / uptime of a device or system - Lusser Law.


If MC connectors are failing, I think their failure rate should be reduced by a factor of 100.

Impossible. The only thing 100% certain is death and taxes ;-)
 

solardad

Solar Addict
In my opinion, these installers want to get rid of RSD to not have to take the time to install it and have their poorly done connections fail.
Disagree. Any additional hardware that is required for a setup offers an installer an automatic upsell and an opportunity for an additional item to be marked up. I saw it before I built my DIY setup when comparing quotes from 3 installers. No different than when you bring your car in for a brake job and the repair shop jacks the prices.
 

Hedges

I See Electromagnetic Fields!
Really..? I am all for safety and would rather reduce any chance of a system failure or fire. Reducing the number 'moving pieces' tends to extend the overall performance / uptime of a device or system - Lusser Law.




Impossible. The only thing 100% certain is death and taxes ;-)

I only called for a factor of 100, that is, reduce connector failure rate to 1% of its current rate. I didn't ask for a 100% reduction.

"no more than 1 incident per 10,000 installations"


"approximately 139.64 million housing units in the United States"


Or maybe 213 single-family dwellings? At least one of these figures is wrong.


How does 13,900 home fires due to PV sound to you? I propose reducing that to 139 (not zero) by using connectors 100 times more reliable than the typical MC4 connector today. It is well known that connectors are the least reliable part of electronics.

Beyond that, AFCI should reduce it to about zero. (as far as DC PV wires go; AC wires could still cause fires unless also on AFCI.)

Probably, making connectors 100x more reliable is a tall order for a cheap plastic and tin-plated part. Electronics is cheaper, so keep the Cr@p connectors and just bank on AFCI?
 

Hedges

I See Electromagnetic Fields!
Disagree. Any additional hardware that is required for a setup offers an installer an automatic upsell and an opportunity for an additional item to be marked up. I saw it before I built my DIY setup when comparing quotes from 3 installers. No different than when you bring your car in for a brake job and the repair shop jacks the prices.

Not clear that would be the case. Did auto dealers clamor for air bags to be required so car prices would be higher?
Demand is elastic.

Now as for micro-inverter manufacturers/installers, I'm sure they were happy with RSD and AFCI rules, so long as they slipped beneath the limits.
Anything that outlawed or raised the price of the more efficient, more cost effective string inverters is a huge benefit to them.

"To some, this might just sound like old school installers shaking their fists at clouds. Post-NEC 2017, the market immediately and dramatically shifted to MLPE with SolarEdge and Enphase making up more than 92 percent of the residential inverter market at last glance. Obviously not everyone in that majority is doing so against their will to meet NEC 2017."

Back in the mid 2000's when I put in solar, I reviewed the CEC report on installations. SMA had over 50% of the systems with their Sunny Boy string inverters, and 20 other companies shared the other < 50%. SMA was pretty much the only player with a good product. Now, there are several brands of quality high-voltage string inverters. But RSD, if it costs $50 per panel, is a big cost hit.
 

solardad

Solar Addict
How does 13,900 home fires due to PV sound to you? I propose reducing that to 139 (not zero) by using connectors 100 times more reliable than the typical MC4 connector today. It is well known that connectors are the least reliable part of electronics.

Sounds great reducing it to 139.
 
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Haugen

Tron God
My cost would not have changed. I had a set cost for the full install and the RSD was on the drawing.
My metal roof isn't going to catch fire
 

GXMnow

Photon Sorcerer
The Tigo RSD boxes I am looking at using will increase the connection count from 3 at a pair of panels in series, to 6 total connection for the pair of series panels. So yes, adding RSD doubles the number of MC-4 connector points in a typical system. After looking up a bunch of stuff on solar panel and wiring failure, I did find one big common theme. "MC-4 (compatible) connectors are not all created equally". There are many cheapo copies that are not well made and don't hold proper dimensions etc. Since the plastic housing snap together, you may not notice if the metal terminals are a lose fit. In most cases, using the same brand for both sides works good enough, but better quality connectors, and the same on both sides is even better. Mixing brands is a recipe for disaster. This can make it tough when the solar panels come with them pre installed, and the RSD boxes also already have them installed. If they do not match up well, it could certainly be a problem. If there is any doubt, you may end up having to cut off and replace a connector to be sure they mate nice and tight. When I get my panels and Tigo RSD boxes, I will certainly double check the fit of the connectors and replace any that do not fit tight.
 

ArthurEld

Photon Sorcerer
I only used the MC4 connectors already on the solar panels and on the cables AltE sent.
When connecting to a solar panel I would think using mismatched MC4 brands is common.
 
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