Fencing questions

HuckMeat
HuckMeat Registered Users Posts: 24 ✭
in PV Installers Forum - NEC, Wiring, Installation #1
So my installation passed except for two things:

1) I need to fence around my groundmount installation. Do I need to have a gate in this fence? And would a 4 strand smooth (barbless barbwire) wire fence be adequate? (It's a rural area, I have 10000' of 4 wire barbless fence installed for cows/horses.).

2) I need to move my battery enclosure further away from my inverters. (It extends more than 6" beyond the front face of the inverters). I have an outback flexmax 500 (2 outback inverters with AC & DC enclosures on each end of the inverters. Can I move the battery box out from under the inverters and have them be under the DC enclosure and charge controllers, but clear of the inverters? I'd ask the inspector, but I got home and got the notice tonight, and won't have access to him until after the long weekend.
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #2
    Re: Fencing questions

    Definitely ask the inspector what will suit, as he's the one who will say "okay" on both issues.

    Frankly, these requirements seem quite silly to me. :roll: Especially the one about moving the batteries (and thus making longer DC wire runs - not good).
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  • dsp3930
    dsp3930 Solar Expert Posts: 66 ✭✭✭✭
    #3
    Re: Fencing questions

    1) Do you have anything exposed that is reachable by a 6 foot tall person that is not enclosed or conduit encased? Solar panels also count here if the pv wires are exposed AND reachable. If so, then you either need to encase it or put a lockable fence around it that can not be climbed through. (My array combiner box is 6 feet above ground and all wires to/from are conduit encased, so a fence isn't required)

    2) I don't know the answer to this one. My battery bank starts about 2 feet to the right of my inverter.
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  • n3qik
    n3qik Solar Expert Posts: 741 ✭✭
    #4
    Re: Fencing questions

    Here is some info on battery enclosures:
    From 2005 NEC
    In no case should charge controllers, switches, relays, 
or other devices capable of producing an electric spark be 
mounted in a battery enclosure or directly over a battery bank.

    The NEC requires certain spacing around battery 
enclosures and boxes and other equipment to allow for 
unrestricted servicing—generally about three feet [110.26].
 Batteries should not be installed in living areas, 
nor should they be installed below any enclosures, 
panelboards, or load centers [110.26].

    With the above said, you will need to move them to the left/right 3+ feet.
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #5
    Re: Fencing questions

    After reading Ken's post I have to say there's not one single install on our lake that would pass NEC inspection. :roll:

    Good thing we don't actually have to deal with such. :p
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  • n3qik
    n3qik Solar Expert Posts: 741 ✭✭
    #6
    Re: Fencing questions
    Cariboocoot wrote: »
    I have to say there's not one single install on our lake that would pass NEC inspection. :roll:
    :p

    You have plenty of water to put the fire(s), so not that big of an issue.:D
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #7
    Re: Fencing questions
    n3qik wrote: »
    You have plenty of water to put the fire(s), so not that big of an issue.:D

    Hey! You're not supposed to put water on electrical fires! :D

    Besides, we need it all for the forest fires. :cry:
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  • n3qik
    n3qik Solar Expert Posts: 741 ✭✭
    #8
    Re: Fencing questions
    Cariboocoot wrote: »
    Hey! You're not supposed to put water on electrical fires! :D
    It will only be an electrical fire till the battery melts, then it become a structural fire, then becomes a forest fire.:cry::cry:
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  • HuckMeat
    HuckMeat Registered Users Posts: 24 ✭
    #9
    Re: Fencing questions

    It's a steel enclosure, vented outside, with 4 AGM's in it. He was fine with the battery setup, he just didn't want it sticking out in front of the inverters - If the battery box didn't extend more than 6" from the front edge of the inverters, I'd have been fine (the enclosure was 9" beyond the front of the inverters).

    I can move it right and keep the same inverter cable length by flipping the conduit bend.

    No word back on my questions, so I'm going to put a 4 strand barbed wire around it this weekend, with gates, and see if he is OK with that.

    The polemounts are on 8' poles, and everything that is below the 6' mark is in locked enclosures or conduit. I suppose a really tall guy could go up and jump and grab a handful of the PV cables before they enter the conduit. :confused:

    Oh well, what he says goes...
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  • stumpy40
    stumpy40 Solar Expert Posts: 35 ✭
    #10
    Re: Fencing questions

    So it is true that a pole mounted system needs all wiring in raceways. I posted a thread asking this exact same thing and after reading this confirms my question.

    The Trina modules I am using do not have knockouts for conduit...how are you supposed to do this? I am in a locale that does not have permitting or inspections only utility company will inspect after install is complete for interconnection agreement. I don't mind running conduit...its not that expensive, just more work.
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  • Slappy
    Slappy Solar Expert Posts: 251 ✭✭✭✭✭✭
    #11
    Re: Fencing questions

    1) I need to fence around my groundmount installation. Do I need to have a gate in this fence? And would a 4 strand smooth (barbless barbwire) wire fence be adequate? (It's a rural area, I have 10000' of 4 wire barbless fence installed for cows/horses.).

    the fence is probably required in your area because of "live stock". a gate would be good for ease of access, unless you can squeeze between the strands with no problems for maintenance? but ask the inspector on that call. ;)
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  • dsp3930
    dsp3930 Solar Expert Posts: 66 ✭✭✭✭
    #12
    Re: Fencing questions

    All exposed wiring does not have to be in conduit. (if exposure rated)
    It has to be out of "reasonable human/animal reach".

    Think of a 6' person jumping to grab at the PV wire. If it could be touched, then it needs to be in conduit or a fence put around the array. If a fence is used, it needs to be built in such a way that a child could not squeeze through any openenings and must be securable (Ziptie lock, padlock, etc on the gate) so the average person can not enter without climbing over the fence. I'm not sure about minimum height.

    If you have a ground mount array with conduit run up to the combiner, and then conduit run from the combiner up above human reach level, the remainder can be exposed IF it is weather rated.

    I am not an expert ... just someone who has gleaned this from extensively talking with others on the subject. If you are an expert -- feel free to add your corrections. :-)

    David
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  • JayWes
    JayWes Registered Users Posts: 6 ✭
    #13
    Re: Fencing questions

    Latestissue of Home Power states that there is at least one manufacturer that suppliers modules with a Junction Bosx for this reason. However connecting up wiring in a junction box requires care as the modules are energized if lighted. Try a very dark canvas cover.
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,637 admin
    #14
    Re: Fencing questions

    It is also why the went to "Locking Connectors" (connectors that require a tool) on the solar panels--Complies with NEC and does not need a junction box on the solar panel.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • JayWes
    JayWes Registered Users Posts: 6 ✭
    #15
    Re: Fencing questions

    The other code (National Electrical Safety code) generally requires a 7 foot fence and a distance from the fence to the exposed wiring for substations. If the fence can be accidentally energized, it should be grounded. Usually swimming pools require 6 foot fences.

    :roll:Take into account also that animals love to chew on wiring (I had a thermostat and a $500 circuit board destroyed in a furnace due to animal damage. This was damage to a short length of exposed thermostat wiring) A high voltage DC Solar Power wire could do-in a critter. The latest in PA is critters chewing though the Neutral wire on Triplex services, which can, depending on whether the whole cable comes down (and which end comes down) or not, can cause a large Homeowners insurance policy claim. The fine print in utility service agreements excludes the power company liability due to misguided critter actions.

    Believe me. you do not want to take any chance on a curious kid or even a pet getting involved with a lethal DC circuit that can not be easily turned off.:grr
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  • JayWes
    JayWes Registered Users Posts: 6 ✭
    #16
    Re: Fencing questions

    The issue on the batteries is the equipment access which is covered in article 110 of the NEC. Here is an alternate that should work: I have used this on several electrical installations with transformers and for battery disconnect switches:Move the inverter forward on (Uni-strut or wood posts and spacers, so the front it is less the front is less then 6" back of the front of the batteries.

    However, due to Hydrogen out gassing it mounting the inverter box directly over or near the batteries if it is a vented enclosure may not be a good idea if there the batteries are vented wet cell.

    The NEC handbook (available from the NFPA) is a good investment for explaining this and other code related questions.
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