City Ordinance "prohibiting" off-grid and battery backup systems?

The Southern California city I live in has adopted Ca. Electric Code 690 (basically the equivalent of NEC 690), and passed an ordinance adding a subdivision to 690 that states:

"The current carrying conductors of all sources of energy*shall be designed to de-energize, and remain de-energized, from their respective source of energy generation when the utility-supplied service’s main breaker is opened (set to the “off” position) on the electrical system being energized by the aforementioned sources of energy.

*For purposes of this section, “sources of energy” includes alternating current, solar, wind, and fuel cell.
"


I contacted the building department and asked how this ordinance effects off-grid and battery backup systems since the statute specifically refers to "utility-supplied..." Their reply was:

"The point where the current carrying conductors are to be de-energized and remain de-energized shall be immediately adjacent to the point of energy generation or immediately adjacent to a combiner box, if so equipped. This shall apply to all electrical system installations, regardless of location of conductors inside or outside of any structures.

A DC contactor is required so in the event firefighters or anyone else needs to disconnect the power at the main electrical panel, ALL of the conductors inside or outside the structure are disconnected, both the alternating current conductors AND the direct current conductors. Without this contactor, the direct current conductors, with more than 50 volts, would remain energized from the array or combiner box down to the inverter
."


The explanation of the reason for the relay/contactor makes sense. However, by requiring ALL sources of energy to be de-energized when the utility main is turned off (or the grid goes down), defeats the whole point of having a solar system does it not? If the grid goes down you have a really expensive paper weight on your roof!

Anyone else run into this problem or am I interpreting the ordinance wrong?

Comments

  • PhotowhitPhotowhit Solar Expert Posts: 5,824 ✭✭✭✭✭
    Re: City Ordinance "prohibiting" off-grid and battery backup systems?

    I read it as wanting a DC disconnect as well as an AC Disconect and Array disconnect outside... I don't think this is unusual, and easy for pure off grid with batteries outside or against an outside wall adjacent or below their array. I'm not the 'code' guy, in fact just passing through and saw your post checking to see if an electrician type had seen mine...lol.

    FWIW - The guys at the 'building dept' might offer more information, and you might make queries to get further info... Might call in as "Ossie Bluege" (1935 Washington Senators, 3rd baseman) so you could play dumb if asked later.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
  • inetdoginetdog Solar Expert Posts: 3,123 ✭✭✭✭
    Re: City Ordinance "prohibiting" off-grid and battery backup systems?
    jkeener wrote: »
    The Southern California city I live in has adopted Ca. Electric Code 690 (basically the equivalent of NEC 690), and passed an ordinance adding a subdivision to 690 that states:

    "The current carrying conductors of all sources of energy*shall be designed to de-energize, and remain de-energized, from their respective source of energy generation when the utility-supplied service’s main breaker is opened (set to the “off” position) on the electrical system being energized by the aforementioned sources of energy.

    *For purposes of this section, “sources of energy” includes alternating current, solar, wind, and fuel cell.
    "


    I contacted the building department and asked how this ordinance effects off-grid and battery backup systems since the statute specifically refers to "utility-supplied..." Their reply was:

    "The point where the current carrying conductors are to be de-energized and remain de-energized shall be immediately adjacent to the point of energy generation or immediately adjacent to a combiner box, if so equipped. This shall apply to all electrical system installations, regardless of location of conductors inside or outside of any structures.

    A DC contactor is required so in the event firefighters or anyone else needs to disconnect the power at the main electrical panel, ALL of the conductors inside or outside the structure are disconnected, both the alternating current conductors AND the direct current conductors. Without this contactor, the direct current conductors, with more than 50 volts, would remain energized from the array or combiner box down to the inverter
    ."


    The explanation of the reason for the relay/contactor makes sense. However, by requiring ALL sources of energy to be de-energized when the utility main is turned off (or the grid goes down), defeats the whole point of having a solar system does it not? If the grid goes down you have a really expensive paper weight on your roof!

    Anyone else run into this problem or am I interpreting the ordinance wrong?

    I think that you are right to be concerned. The ordinance clearly refers to what happens when there is a utility supplied service in the first place.

    A GTI's output conductors are already designed to stop producing any power when not connected to the grid so that their argument that there must also be a contactor on the DC side of a GTI is overkill. Most jurisdictions require at most that there be an accessible manual DC disconnect before the wires enter the structure, with suitable labeling that the firefighters can find it. Requiring an automatic DC disconnect at or near the panels is pretty much unheard of.

    But for an off grid system, requiring that sort of DC contactor to be driven from the main breaker, which is the service termination of your separately derived power generation system, but not of a UTILITY, does not make sense. If you set up a contactor to be de-energized when the main breaker is opened, there would be no power source that could be used to re-energize the contactor to start the system up again. The most I can see would be a manual switch that operates a contactor driven from the battery, which then disconnects the panels from your CC. And maybe has AC poles or a separate contactor which disconnects the Inverter input from the battery. But, depending on the size of your inverter, that could be a 1000 Amp DC contactor. A rarity and expensive I am sure.

    I am not sure how you should proceed, except by finding an electrician who could get an opinion from an authoritative source on your behalf.

    An off-grid system is very different from a grid-backup system, which would have to include a transfer switch which would automatically disconnect your house wiring from the grid and connect it to the inverter. For an off grid system, at most there would be a transfer switch to allow a generator to be used. These automatic transfer switches exist as part of hybrid system inverters. Note also that the grid disappearing is not the same as opening the main breaker, although opening the main breaker will make the grid disappear from the view of your backup system. :-)

    And, as mentioned on other occasions here, if the firefighter are really concerned about their safety, they will not trust any contactors you have installed and will put a fire axe through a panel or two anyway.

    In all cases, the important thing from the point of view of any first responder is to have a clear label at an outside panel (service entrance) which indicates that there is more than one source of power to the panel and to the house.

    If your back system does not go through the main panel but uses either dedicated outlets or a set of transfer switches outside the main panel, they need to know about that too.
    SMA SB 3000, old BP panels.
  • jkeenerjkeener Registered Users Posts: 19
    Re: City Ordinance "prohibiting" off-grid and battery backup systems?

    I designed my system to be as safe or safer than they seem to want.

    I have an exterior AC disconnect (required by utility company) and an exterior DC disconnect. The DC contractor runs through the DC disconnect as well. So the firefighters just need to turn off the main AC and exterior DC disconnect and the whole house (AC & DC) de-energizes. I am even placing a map of the disconnects and "shut down" procedures on a plaque at the main panel.

    I also have redundant AC & DC disconnects inside "in view" of the inverter and battery banks to satisfy 690.

    The guy at the building department also said, in a phone call, that the point of the DC contactor "is to make sure there is no power coming from the roof, down the side of the house when firefighters turn off the main breaker." But that then assumes the combiner box is on the roof! I have a two story house... now I have to buy a 30' ladder to fix a tripped breaker lol

    I think I will wait until my building permit is denied to make a fuss.

    BTW- My neighbor is a firefighter and he said they always tarp the PV arrays regardless of any disconnect. That, or "let it burn."
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: City Ordinance "prohibiting" off-grid and battery backup systems?

    you have batteries in your system and that disconnect will not shut them down so there will still be energy in the home in spite of disconnecting of the pvs which only produce in daylight. ask the fireman if they throw tarps on pvs during a night fire too just to see if he knows anything about this or not. i'd be willing to bet that they would throw the dc disconnect and put a tarp on the pvs even at night and think there's no power in the house. of course it may not be wise to inform him there's still power in the house even if he does show some common sense as they may require 2 dc disconnects to also disable the batteries in addition to the pvs.:cry:
  • jkeenerjkeener Registered Users Posts: 19
    Re: City Ordinance "prohibiting" off-grid and battery backup systems?
    niel wrote: »
    you have batteries in your system and that disconnect will not shut them down so there will still be energy in the home in spite of disconnecting of the pvs which only produce in daylight. ask the fireman if they throw tarps on pvs during a night fire too just to see if he knows anything about this or not. i'd be willing to bet that they would throw the dc disconnect and put a tarp on the pvs even at night and think there's no power in the house. of course it may not be wise to inform him there's still power in the house even if he does show some common sense as they may require 2 dc disconnects to also disable the batteries in addition to the pvs.:cry:

    The exterior dc disconnect disconnects the batteries and the dc contactor that then disconnects the pv arrays. It's a giant Siemens 200 amp two pole safety switch. This is in addition to the pv combiner disconnect which the contactor shuts off.

    So I am doing what the ordinance requires but with two disconnects instead of one (main breaker)
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: City Ordinance "prohibiting" off-grid and battery backup systems?

    i guess it's good that you've got that angle covered too so i don't think they should have argument against you. i'd still want to hear the fireman's answer just for kicks.;)
  • jkeenerjkeener Registered Users Posts: 19
    Re: City Ordinance "prohibiting" off-grid and battery backup systems?

    I think the reply will be the standard, "let it burn." Lol
  • jkeenerjkeener Registered Users Posts: 19
    Re: City Ordinance "prohibiting" off-grid and battery backup systems?

    But I cheated and placed a placard indicating three power sources. So I can't hide the batteries haha
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: City Ordinance "prohibiting" off-grid and battery backup systems?

    seems to me if any would just let it burn after you've fully complied with their requirements that they would be subject to being sued.
  • Organic FarmerOrganic Farmer Solar Expert Posts: 128 ✭✭
    Re: City Ordinance "prohibiting" off-grid and battery backup systems?

    I recommend that you install a fire-sprinkler system. I had to install a sprinkler system in on e apartment building I owned. I was hesitant to do it, but the Fire Marshal required it. After it was all done, however, my opinion changed. Sprinkler systems are actually very simple, and not terribly expensive.
  • solarixsolarix Solar Expert Posts: 713 ✭✭
    Re: City Ordinance "prohibiting" off-grid and battery backup systems?

    If it was me I'd try to implement one of the distributed optimizer products that put a converter on each module to do the MPPT optimization. Most of these have the additional benefit of shutting of the module when the system turns off. They are intended for GT applications but I wonder if they could be used off grid as well. I think the Tigo units are pretty universal. Short of disconnecting the modules, the fire people will always be afraid of you. The SEIA people did some testing and found that even covering an array with a typical tarp doesn't reduce the array voltage below the lethal threshold! This whole issue is gaining steam and the fire codes are in the works to consider requiring module level disconnects.
    Its always interesting to me how local officials are intent upon rearranging the fire safety deck chairs on the titanic global warming, peak oil problem.
  • ggunnggunn Solar Expert Posts: 1,973 ✭✭✭
    Re: City Ordinance "prohibiting" off-grid and battery backup systems?
    solarix wrote: »
    The SEIA people did some testing and found that even covering an array with a typical tarp doesn't reduce the array voltage below the lethal threshold!

    I'm not surprised that the voltage stayed high (voltage is not irradiance dependent), but it's not the voltage that kills, it's the current.
  • jkeenerjkeener Registered Users Posts: 19
    Re: City Ordinance "prohibiting" off-grid and battery backup systems?
    solarix wrote: »
    This whole issue is gaining steam and the fire codes are in the works to consider requiring module level disconnects.
    Its always interesting to me how local officials are intent upon rearranging the fire safety deck chairs on the titanic global warming, peak oil problem.

    Speaking of that....here is the draft SOP some cities are adopting from Cal Fire. It doesn't seem to address a DC contactor!

    http://osfm.fire.ca.gov/pdf/reports/solarphotovoltaicguideline.pdf
  • solarixsolarix Solar Expert Posts: 713 ✭✭
    Re: City Ordinance "prohibiting" off-grid and battery backup systems?
    ggunn wrote: »
    I'm not surprised that the voltage stayed high (voltage is not irradiance dependent), but it's not the voltage that kills, it's the current.
    Doesn't take much irradiance to generate the 10 mA or so needed to mess up your heart real good.
  • inetdoginetdog Solar Expert Posts: 3,123 ✭✭✭✭
    Re: City Ordinance "prohibiting" off-grid and battery backup systems?
    solarix wrote: »
    Doesn't take much irradiance to generate the 10 mA or so needed to mess up your heart real good.

    You are neglecting the difference in effect of AC versus DC. AC can easily induce fibrillation while DC will not.

    For DC, in the worst likely path, from arm across heart, 300-500 ma of DC is needed to produce fibrillation, while AC can have the same effect at less than 30 ma, as you noted.
    For a panel with Isc of 8 amps, the difference between standard sunlight and full moonlight, would reduce a moon-shock to only 8ma. A tarp should do better than that, particularly for interior panels in the array. Maybe the local code should be amended to prohibit bypass diodes also. :-)
    SMA SB 3000, old BP panels.
  • Robin GudgelRobin Gudgel Registered Users, Solar Expert Posts: 58 ✭✭✭✭
    Re: City Ordinance "prohibiting" off-grid and battery backup systems?

    NEC 2014 is going to require an emergency shutdown of the PV system. It can also be interpreted to requires the battery terminals to be disconnected on battery based systems. Shutting down based on a power outage is a real problem as some systems like ours would require resetting manually. Having a separate switch that can be located where ever the utility or fire marshal required is available now.
    Contactors are a simple method to disconnect the PV array. They also reconnect when the power is turned back on. They do eat up at least 5 watts of power 24 hours a day. Putting a contactor in the battery circuit of a back up inverter is absurd! They are very expensive and very inefficient 24 hours a day.
    MidNite has a system now that uses virtually no power. It can disconnect the PV array and battery based inverter. The Birdhouse can be located anywhere. IT is an outdoor enclosure that is easily identified as for this purpose. It also talks to you and explains if there is still voltage present (it knows day and night).
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: City Ordinance "prohibiting" off-grid and battery backup systems?

    :confused:They want the batteries disconnected when the grid goes down? That can't be right. :confused:

    Or else it's time for ....

    "How many electrical engineers does it take to change John Wiles's mind?"

    :p
  • vtmapsvtmaps Solar Expert Posts: 3,741 ✭✭✭✭
    Re: City Ordinance "prohibiting" off-grid and battery backup systems?
    It can also be interpreted to requires the battery terminals to be disconnected on battery based systems.
    <snip>
    Putting a contactor in the battery circuit of a back up inverter is absurd!

    I am not sure I understand what this pertains to. Are you saying that when the grid goes down, the batteries must be automatically be disconnected from a backup inverter? Yes, that is absurd.

    But if the proposed rules are to require a remote (from outside the burning building) battery shutoff, I can see the logic (and feel the $$ pain). As it stands now my panels can be shut off at the combiner on the pole mount, but someone would have to enter my burning premises with a battery wrench to de-power my Epanel.

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
  • jaggedbenjaggedben Solar Expert Posts: 230 ✭✭
    Re: City Ordinance "prohibiting" off-grid and battery backup systems?

    Here's a question pertaining to whether they allow the installation of a battery back up system...

    Did they delete 705.40? Particularly the last sentence?
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: City Ordinance "prohibiting" off-grid and battery backup systems?

    is wiles going too far? it's like rule making that the gas in driving a gas driven car is hazardous so while on the road you must cut off the source of the gas to protect firefighters who may need to come. no gas=no driving. ok, maybe that's a bad example as it could be while parked in a driveway off the road that the gas supply is to be shut down, but you need the gas to get to the roadway. come to think of it, it's a good thing wiles has no jurisdiction over car wiring. can you picture that??????

    in either case the overprotecting rule making brings it to non-functionality, or in simple terms, it defeats the purpose.

    i think firefighters have far more potentially dangerous things to worry about than charged batteries in a home. just one can of hairspray is more of a hazard than the electrical hazard from batteries imho.
  • halfcrazyhalfcrazy Solar Expert Posts: 720 ✭✭✭
    Re: City Ordinance "prohibiting" off-grid and battery backup systems?

    Well the intent of the new proposed NEC vers Robin linked is to have a Rapid shut down of the complete system. If the Firefighters roll up they need a friendly easy to fing single Emergency disconnect button that will disconnect the batteries from the inverter and disconnect the PV at the combiner box. This is relatively simple to do but of course it does add expense to a system. Is it worth the expense? Hard to say for sure but as an X volunteer firefighter I would vote for it.

    This same Rapid shut down program when applied to Grid tie systems says the PV must be disconnected at the combiner level, now this is only on pure grid tie though.

    Ryan
  • jkeenerjkeener Registered Users Posts: 19
    Re: City Ordinance "prohibiting" off-grid and battery backup systems? UPDATE

    UPDATE-

    I turned in my specs with single line diagram including a DC contactor per city ordinance. Not before sending an email to the city attorney objecting to the ordinance.

    Lo and behold, the city "waived" the contactor requirement for me lol
  • Organic FarmerOrganic Farmer Solar Expert Posts: 128 ✭✭
    Re: City Ordinance "prohibiting" off-grid and battery backup systems? UPDATE

    Sweet :)

    You did a good job.
  • jkeenerjkeener Registered Users Posts: 19
    Re: City Ordinance "prohibiting" off-grid and battery backup systems? UPDATE

    Thanks.

    I got my permit issued finally.

    But what stuck out in my mind is the building plan inspector said my design was the only system with battery back-up he had ever reviewed. After reviewing my design, he asked "what happens to the other people's 'solar' systems when the grid goes down and they do not have battery back-up."

    He paused and looked at me and said, "Doesn't that mean they have no power?" I laughed and said "welcome to 'zero-down' solar!"
  • BB.BB. Super Moderators, Administrators Posts: 32,641 admin
    Re: City Ordinance "prohibiting" off-grid and battery backup systems? UPDATE

    Just read somewhere (could not find link), that cities looking for cash may try to sell "licenses" to power companies to sell to their customers...

    And:
    Renewable Energy: Bringing Blackouts Back to California?
    The epidemic of power outages and “rolling blackouts” which nearly shut down California in the early 2000s may be returning. Back then, the culprits were unscrupulous energy providers like Enron and a poorly-thought out process of deregulation. This time, renewable energy would be to blame, as the state has pushed to increase the use of solar and wind energy without ensuring that there is enough traditional power generation to keep the grid stable on cloudy, windless days.
    Although the blackouts haven’t happened yet, some are warning that they could begin to strike in the next couple of years. . . .
    The problem of intermittency of renewable energy is a well known one. Other states, including Texas, are facing similar troubles. California’s energy planners are aware of the problem, too, and they are looking to settle on plans to deal with it later this year. Nonetheless these projections of electricity problems are disturbing for a state with a long history of them, and the fact that there isn’t already a plan to deal with it makes us wonder whether we’re not about to witness another case of green policy failure. We’ll wait and see how this shakes out, but California will need to plan carefully to avoid serious problems down the road.

    Back to ~2000-2001--Drop of a hat and we had $25 Billion in 40 year state bonds to pay for the last power fiasco in California.

    Just immagine the laws when your local government body "sold you" to the power company--More laws that prevent on-site power generation and "too much" conservation or going off grid (in California, it is already illegal to go off grid/generate your own power without paying the utility for the privilege to leave the grid. Small GT solar is the only current exception).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: City Ordinance "prohibiting" off-grid and battery backup systems?

    somebody should be challenging these ridiculous laws they are passing.
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