PV Rapid Shut down Requirements -Ontario Canada

bedpan

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Hey folks... I am looking at diy'ing residential solar system and trying to wrap my brain around code. It's been a bit of a roller coaster as I got denied my grid tied application with Ontario hydro so I switched gears to building a smaller system. After a few phone calls though it seems like hydro might actually give me an approval after all and I am back to designing a larger system again....

So today's question is around rapid Shut down Requirements here in Ontario Canada'land. I have attached a ESA bulletin I found on the topic and I am trying to dissect it.

If I read it correctly rapid Shut down should only be required if the inverter is setup to run in Islanding mode. So a basic UL1741 listed string inverter would not require a seperate means of rapid Shutdown.

Now if I goto a hybrid inverter that supports a critical load sub panel does this now mean I need a means of external rapid Shutdown? If so what does this look like for say a solark style inverter?

My plan is to stage the my install.. starting with about 5-6kW of PV setup to hybrid inverter. No critical loads panel, just a breaker in my main panel. Once I have that working I will then move to a critical loads panel and likely at the same time add a small amount of battery. Then likely add another 5-6kW of panels...

Your thoughts and input are greatly appreciated!

Mike
 

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Hedges

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Just skimming it, I don't see grid-tie only vs. off-grid operation.
What I do see is the older version of U.S. requirement, where high voltage DC is OK if confined to the array, disconnected from wires going further.
That's just one disconnect switch.
The new U.S. requirement disconnect between each PV panel (or group of panels) so nothing in array is more than 80V from anything else.

Maybe just a mechanical switch within 3' of array (possibly mechanical extension to remote handle) might satisfy requirement.
 

Supervstech

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If rapid shutdown is an issue, aside from the inverter is the fire code for residence roof mounted array shutdown.
 

bedpan

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Just skimming it, I don't see grid-tie only vs. off-grid operation.
What I do see is the older version of U.S. requirement, where high voltage DC is OK if confined to the array, disconnected from wires going further.
That's just one disconnect switch.
The new U.S. requirement disconnect between each PV panel (or group of panels) so nothing in array is more than 80V from anything else.

Maybe just a mechanical switch within 3' of array (possibly mechanical extension to remote handle) might satisfy requirement.

Thanks Hedges,
In the US what does a Rapid shutdown entail with a traditional string inverter? I gravitate to the Sol-Ark (likely not buying due to price), what would be needed for a Rapid shut down on a solark system? I guess I can do some searching on it and try and wrap my brain around it.

Side note. My Fuse panel is in my garage. The garage is insulated but not finished so working in there is pretty easy.

If rapid shutdown is an issue, aside from the inverter is the fire code for residence roof mounted array shutdown.
Not sure I follow Supervs. Should I be checking local fire code as well regarding the solar installation? Had not even considered this beyond making sure panels are properly spaced from edges with walkways in between ridges, troughs and edges.
 

bedpan

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I am struggling with this wording. Anyone able to provide their interpretation for me?

Based on the intent of Rule 64-218, rapid shutdown process can be defined as a process that:  de-energizes PV source or output conductors that are more than 1m. in length on or inside a building, and  de-energized conductors to not more than 30 V within 30 s of initiation. If a combiner is close (not more than 1 m) to a PV array/module, Rule 64-218 does not require a PV module level shutdown. PV conductors within a PV array and up to a combiner box located within 1 m are permitted to remain energized.
 

bedpan

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I am struggling with this wording. Anyone able to provide their interpretation for me?
Alright.. starting to wrap my head around it. Soooo if all the panels run into a combiner box within 1m of the panels then I can have some form of switch to turn off the power from the panels at the combiner box. What Hedges said makes sense now. Just was not following for some reason..

Any idea what this disconnect would be? Something on the side of the house either electrical or mechanical that some how breaks a DC circuit likely about 100' away?
 

Hedges

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100' away? Is that panels on the roof 100 feet away from the switch, or ground-mount panels 100' away from the house?

I read the requirement as a roof-mount array having a switch within 3' of the array. Once switch is opened, nothing more than 3' from the array (and on the house) is energized. Could be mechanical lever, could be relay controlled remotely.

Our new module level requirement is either microinverter per PV module, or for string inverters a box per PV module that is controlled electronically. (some RSD devices have multiple PV panels plugged into one.) It either isolated between modules, or is a switching power supply (optimizer) that drops voltage of each module to about 1V.

Maybe you can have panels down to the eaves and a switch within 3' with pull handle or extension lever within reach.
Not many relays good for 600VDC, but there are some remote-trip breakers (several 150V poles ganged and wired in series.)
 

bedpan

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100' away? Is that panels on the roof 100 feet away from the switch, or ground-mount panels 100' away from the house?

I read the requirement as a roof-mount array having a switch within 3' of the array. Once switch is opened, nothing more than 3' from the array (and on the house) is energized. Could be mechanical lever, could be relay controlled remotely.

Our new module level requirement is either microinverter per PV module, or for string inverters a box per PV module that is controlled electronically. (some RSD devices have multiple PV panels plugged into one.) It either isolated between modules, or is a switching power supply (optimizer) that drops voltage of each module to about 1V.

Maybe you can have panels down to the eaves and a switch within 3' with pull handle or extension lever within reach.
Not many relays good for 600VDC, but there are some remote-trip breakers (several 150V poles ganged and wired in series.)


Cheers again Hedges.. I will need to seek professional help I think with someone that knows the code and what to expect from the inspection. I think you are right though about the disconnect 3' (1m) away. I am not keen however of having a weather exposed box/switch on the roof. I was hoping to go with something like the soladeck combiner on the roof underneath of the panels based on what I have seen so far. There may well be better options though, I am still learning..

I have done some reading on the Tigo Rapid shutdown equipment. It maybe an option as well. Part of the problem is the ESA code is all hidden behind payways. Maybe I just need to pony up and buy the code (which I have a download of) so that I can get access to all the bulletins and amendments.. I will continue to read the code and try and wrap my brain around it but I am hoping to find a Local (ontario based) installer that does not mind giving me an hour or two of time for some beer money.

Cheers,

Mike
 
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