SolArk Install Plan

[ArthurEld]

I've been spending some time on the Mike Holt's forum and reading some of the code. ?
Mike Holt's forum is really good but I have been avoiding reading electric code my whole life.

Anyway, from what I gather so far, another PV disconnect isn't necessary in my case. There is a rule about having a disconnect if the DC enters the building more than 5 feet. But I think RSD or the PV disconnect on Solark will fill that requirement.

Another subject that came up is about having switches that other people could operate. Like if you turn off a switch somewhere but someone else comes along and turns it on without you knowing. I didn't see any mention of "Lock out tag out" but there is talk about having the disconnect near the inverter.

I am not done with this subject. Here's another possibility that I came across- https://www.factorymation.com/SI16-DBL-8

RSD is probably the safest. But there is some chance of malfunction.

 

[Hedges]

RSD where firemen can access it takes care of most requirements.

DC switch, multiple string and UL rated sounds good. Not sure why "300/500/600V" not just 600V, different models or more/fewer switches in line with the PV panels? 8 pole 4 string lets it open both positive and negative. Lockable allows LOTO.

 

[ArthurEld]

The info isn't very clear but I think that isolator handles more Volts with more circuits. Which wouldn't work for me.
I guess you can lock that thing pretty good. I'll see what the county has to say about the plan without the disconnect.

My Reliance 50 amp 10 Circuit Transfer switch arrived already. I'll return the ones I'm not going to use.
I love the way Home Depot and Amazon let me try stuff out then return it when I find something better or cheaper.

 

[Hedges]

Looked to me like it would isolate four PV strings, disconnecting both positive and negative leads. So long as rated for your highest open-circuit voltage, it seemed like a good fit.

Maybe RSD will satisfy requirements.

Home Depot - tools too. The associates call it "the free rental program".

 

[ArthurEld]

Looked to me like it would isolate four PV strings, disconnecting both positive and negative leads. So long as rated for your highest open-circuit voltage, it seemed like a good fit.

Maybe RSD will satisfy requirements.

Home Depot - tools too. The associates call it "the free rental program".

Thanks Hedges.
I'll cut off the wire ends that I striped and put everything neatly back in the box.

 

[ArthurEld]

I submitted my permit paperwork.
My county has a website so I can follow the progress.
Hopefully they will approve everything next week.

 

[ArthurEld]

I can check the status of my permit online and it looks like everything is approved.
Except they don't like the PDF engineer seals and signatures.
I didn't forge them so I guess I can fix that easy enough.
I am anxious to have to Solark delivered but I'm sticking to my plan to wait until the permit is approved.

 

[ArthurEld]

I waited a couple days to see if the building department would get ahold of me to tell me there's a problem.
They didn't contact me.
So, I talked to them and all they want is plans with original Engineer stamps and signatures.
I'm going to ok shipment of my Solark, panels and the rest of my system.

 

[ArthurEld]

My permit was approved today. ?

My Solark 12K and thirty 330W Qcells panels will be delivered soon.

 

[ArthurEld]

One suggestions for the AC Disconnect - Engineeer775 puts in a Double Throw Disconnect instead of the simple disconnect. In the Down position it bypasses the Sol-ark and feeds the Critical Loads panel from the Main breaker panel. In the Center position it cuts off all power past the Main Breaker panel. In the Up position (normal running position) it feeds the Sol-Ark from the Main breaker panel. With the double throw switch, if you have to take the Sol-Ark or down-stream systems down for maintenance, the critical loads still gets fed with a simple switch lever. Something similar to this double throw one - https://www.homedepot.com/p/GE-60-A...-Double-Throw-Safety-Switch-TC35322/202978651

I am still very confused about this AC disconnect.
I don't think the switch you referenced is right for my setup.

The transfer switch I am using doesn't work like a critical loads panel.
My transfer switch has 2 separate wires for each circuit and I am fairly sure I don't want all of those going to the disconnect.
The only other wires come from the Solark.

But I see a problem with my setup. Even if the AC disconnect is turned off. The Solark could still send AC from the batteries to the transfer switch and to the loads. The other problem is that even if the AC disconnect is turned off the main power is still live for all of the wires going from the main panel to the transfer switch. I am confused about whether that is ok.

 

[ArthurEld]

I've had this AC disconnect on the back of my mind for a long time.
And I think I finally understand at least part of the purpose.

It is so first responders know the inverter won't be able to send power to the grid.

They already know how to cut power going into the house but they want to be sure no power is trying to come out of the inverter to the grid.

The thing that still confuses me though is what stops the inverter from sending power from the batteries to the house.

Even if the grid is disconnected and PV is disconnected it seems like the inverter could still send power to the house from the batteries.

I have to understand how first responders can be sure that doesn't happen.

I've got more digging to do. Some day this stupid little subject will stop bugging me.

 

[ArthurEld]

The installers and electrician came yesterday and will come again tomorrow to finish up.

The AC disconnect is going outside and the electrician said the laws are old and haven't caught up to batteries yet.
So, the AC disconnect is so they know the grid is disconnected from the inverter.

The RSD will shut down the panels.

I have seen mention of having a battery disconnect outside for first responders but I guess it hasn't made it to the code yet. Seems like RSD should shut down the inverter to stop all electricity going anywhere.

Anyway, I'm going to be up to code.

I will think about adding a battery shut down outside or some other ways to make the system safer for first responders. Maybe the inspector will demand a battery shutdown.

The other piece of the puzzle that was confusing me was the pass through box that is used for switching from PV cable to regular wire.

These guys had already brought some boxes with flashing that are used to transfer the wire types and go into the attic in conduit. I'll post a picture tomorrow. I will try to return the pass through box I got from AltE.

That was the only piece I didn't use from the stuff AltE put together for me.

I ordered the emergency stop mushroom button for the rapid shutdown but it won't be here until Saturday.

 

[Hedges]

RSD would disconnect PV, but not stop inverter from making AC.
Oh, by "Should", you meant you thought code ought to require it, not that hardware has that function?
The code required voltage and watts between any pair of wires on the roof to drop below something like 80V and 300W within 30 seconds. Maybe the watts part got dropped; single panels are bigger than 300W now.
Exception for BIPV like shingles, in which case you could have 600V 10kW on PV wires inside the attic.

They may have been thinking of grid-tie, where UL1741 guarantees inverter shuts off if grid disconnected.
Two sources of power - automatic generators have been around forever. Battery backup is no different. Did code ever require obvious generator disconnect?

Battery voltage reaching inverter doesn't seem like a hazard to me.
Maybe AC going through the house is. A relay to interrupt AC out of the inverter would be easier than the lower voltage higher current from battery.
But do you have a lithium battery with BMS and disconnect, that you could tap into?

 

[ArthurEld]

RSD would disconnect PV, but not stop inverter from making AC.
Oh, by "Should", you meant you thought code ought to require it, not that hardware has that function?
The code required voltage and watts between any pair of wires on the roof to drop below something like 80V and 300W within 30 seconds. Maybe the watts part got dropped; single panels are bigger than 300W now.
Exception for BIPV like shingles, in which case you could have 600V 10kW on PV wires inside the attic.

They may have been thinking of grid-tie, where UL1741 guarantees inverter shuts off if grid disconnected.
Two sources of power - automatic generators have been around forever. Battery backup is no different. Did code ever require obvious generator disconnect?

Battery voltage reaching inverter doesn't seem like a hazard to me.
Maybe AC going through the house is. A relay to interrupt AC out of the inverter would be easier than the lower voltage higher current from battery.

The AC going through the house from the battery seems dangerous to me. The first responder flips the AC disconnect and hits the rapid shut down but there's still AC going to the house. I doubt it will ever hurt anyone but it doesn't make sense to me. I try to make sense of this stuff even though I'll never use it.

But do you have a lithium battery with BMS and disconnect, that you could tap into?

I will have to think about that one. Right now I have a 48V 100AH AGM battery. My LFPs are resting.

 

[ArthurEld]

We ended up using 2 Soladeck boxes to transfer from solar wire to conduit through the roof.

 

[ArthurEld]

RSD would disconnect PV, but not stop inverter from making AC.
Oh, by "Should", you meant you thought code ought to require it, not that hardware has that function?
The code required voltage and watts between any pair of wires on the roof to drop below something like 80V and 300W within 30 seconds. Maybe the watts part got dropped; single panels are bigger than 300W now.
Exception for BIPV like shingles, in which case you could have 600V 10kW on PV wires inside the attic.

They may have been thinking of grid-tie, where UL1741 guarantees inverter shuts off if grid disconnected.
Two sources of power - automatic generators have been around forever. Battery backup is no different. Did code ever require obvious generator disconnect?

Battery voltage reaching inverter doesn't seem like a hazard to me.
Maybe AC going through the house is. A relay to interrupt AC out of the inverter would be easier than the lower voltage higher current from battery.
But do you have a lithium battery with BMS and disconnect, that you could tap into?

I finally got my RSD mushroom button

I connected it and when I hit the button it does shut down everything going in or out of the inverter. That makes sense.
It doesn't turn the inverter off and when I pull the button back out AC comes from the inverter again.
I will be able to call for the inspection soon.

 

[VantoHouse]

I am new to this forum, but already appreciate what I have learnt from it. I am looking to install a similar set-up to the one described in this thread. However, what happens to the critical loads if the SA develops a fault and shuts down while the house is unoccupied (nobody is around to manually transfer the critical loads back to the grid). Do the critical loads go dark along with the SA? I would want the critical loads transferred over to grid power. Could I just use an automatic transfer switch in place of the manual transfer switch, in order to accomplish this? Thank you

 

[Hedges]

You should be able to set up an automatic transfer switch.

I have same concern with mine; inverter control board has to be functional to close the NO relay sending grid to protected loads.
I have manual bypass, but not automatic.
My first thought is a simple relay with 120V coil held by AC on protected side, but something more robust should be used to separate grid from inverter output.

 

[ArthurEld]

I get F18 faults sometimes and the Solark stops sending power to some of the loads. It only effect one of the 120V outputs so only loads on that side go out.
I have a manual transfer switch and I can switch the loads to grid so they come back on. The Solark resets itself after a few minutes and everything comes back on anyway.
Since I am away from my system I set the transfer switch to grid and I would only lose power to those loads if the grid went down. Then I would have to manually switch the loads back to the inverter.
We haven't had a power outage since I installed my system so everything always works. But I will have to get this issue ironed out.
I will probably ask Solark support to recommend someone to come and take a look.

 

[DerpsyDoodler]

I get F18 faults sometimes and the Solark stops sending power to some of the loads. It only effect one of the 120V outputs so only loads on that side go out.
I have a manual transfer switch and I can switch the loads to grid so they come back on. The Solark resets itself after a few minutes and everything comes back on anyway.
Since I am away from my system I set the transfer switch to grid and I would only lose power to those loads if the grid went down. Then I would have to manually switch the loads back to the inverter.
We haven't had a power outage since I installed my system so everything always works. But I will have to get this issue ironed out.
I will probably ask Solark support to recommend someone to come and take a look.

can't they do any sort of remote diagnostics on the inverter? can't they have you gather and send logs? (does it have any?)