There is a reason code does not require OCPD's for 2 strings or less.
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I think you are sorely mistaken on your statement that nothing will happen to that #12awg wire that has a nail through it. the nail is not a good quality splice and will heat up, start arcing, and show definite potential to be a fire hazard... the cable 20' away will not be hot since, but the actual nail puncture is definitely a problem.Leave a comment:
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Unless you have more than 2 parallel strings, there is no requirement for OCPD's as solar panels are current sources, not voltage.
Example lets say you have two parallel strings using 12 AWG conductor, and each string Imp = 9 amps x 2 = 18 amps. What happens to a 12 AWG conductor with 18 amps flowing all all day shorted out?
Nothing!
Now if you were to drive that nail into 120 VAC voltage source like from the POCO and short it out and you have a FIRE instantly.Leave a comment:
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Hi Sunking - I'm a ticketed electrician, and yes you are correct about the CEC applying to me (although grey as you put it in this case :P). No I am not getting it inspected, but I am not allowed (under CEC) to run loose single conductor in the walls for anything other than ELV signal wiring. It is required by code to be run in a conduit or armored cable since it is a more fire-hazard type of energy than AC power. If the wire gets hit by someone hanging a picture or shelf, there are no roof top fuses to open and cut the current flow. I was also told that rule was added in conjunction with the birdhouse/Rapid Shut Down rules to protect firefighters and such... Well... no firefighters at my cabin so I'm not worried about them, but I do like to make the installation as bulletproof as possible on that front. I was originally going to run flex through the ceiling/wall and just pull a pre-made 40' #10 PVU cable set through but i can do it cheaper with teck90 cabling since I can probably get it for free from work.
Sooo I suppose the question was more about the roof penetration than anything. I see gasketted PVC roof entries with built in glands, but since I want to transition to another cabling type (or metal raceway), I'm not sure about which method is best for sealing the physical penetration...
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Well unless you are pulling a Permit and have an Inspections, then code is a grey area and not enforceable. Anyway has nothing to do with your application.
I assume you are you are Canadian under CEC? If so I can tell you with 99% certainty there is nothing that would prevent you from running wire/cable in walls, attics, drop ceilings, or whatever space you want to use. Unless the area is wet or in classified Hazard you can run wire/cable. That is the default standard of how it is done. Ever been in new construction and see any wiring? No it is all kept out of sight safe and sound where it is not accessible exposed to dangers. I say 99% because I am in the USA and CEC mirrors NEC and lags a cycle behind us. Few minor differences but basically the same requirements.
Not going to tell you how to wire your system, I do not care, but what I will tell you is running wires in walls and ceilings is perfectly fine and complies with codes. In fact highly desirable because it offers protection and looks better hidden. In other words it is an Option open to you, so you do not have to eliminate it based on code because it is code compliant to do so. Only catch is it must be separate from your AC power wiring and Visual Identification. Both conditions are easy to meet. Don't run with AC power wires/cables, and use different colored conductors except Black and White combination which is 120 VAC. Say red and Black. Where system wires must share same space like an Inverter or switch, each system shall be compartmentalized with a divider.
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Penetration into roof via junction box?
Hi guys,
I have almost all aspects of my off-grid solar install figured out now. I'm building an enclosed "closet" to mount on the back of the cabin to put the batteries and electronics in (separated and vented the battery compartment) and now I'm trying to figure out the actual wiring portion.
I have a new tin roof I'm mounting everything on, and so I would like to find a good way to penetrated into the attic space, and then run the PV wiring over to the edge of the house, down the inside of the wall, and pop out the wall inside the electronics enclosure to connect to the charge controller.
My current idea is to drill a 1" hole in the roof, and run an armored cable (like AC90 but in Canada we have Teck90 which is stranded and armored with waterproofing and burial ratings) through the structure up to the whole. I'll use a cable connector to enter the armored cable into the PVC box and then use waterproof glands to enter the Panel's PVU cabling into the same PVC box. Splice cables together, and silicone seal the box to the roof (therefor covering the whole I made for the cabling). my racking sits about 3" about the roof, and the PVC box I have is about 2.5" tall so I'm aiming to put the box below the panels to help minimize sun exposure and help minimize potential for water ingress...
Does this sound like a good idea? What do you guys do?
I didn't think it was a good idea to just run 30' of PVU cable through the ceiling and walls.... In fact I think it's against electrical codes here anyway...
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