mrzed001
Voice of reason
You have to protect LFP cells too ... from fauna, flora, mechanic damages, short circuit, moisture, heat, cold, ...
And for that you need some box or cabinet.
Safe Enclosure recommendations?
- Thread starter coding2021
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And for that you need some box or cabinet.
freedomlives
New Member
I find a lot to critique over here in Europe, but building houses out of nonflamable materials is not one of them!
OffGridForGood
Catch, make or grow everything you can.
I put my entire system in a metal building (my workshop) 100 feet away from the house, used direct-buried 3C6AWG to the house for my critical loads panel and another line beside it to feed utility power back to the system for the short cloudy days we get in Nov-Feb. Part of the reason was to keep the solar off my house, and part was to keep my wife off my back! LOL
Seriously, though, the inverter-fans, the space it all takes, wiring and upgrades, it just made sense to keep most of it out of the house for me.
I used 100A T-class fuses & MCCB breakers between my tower 600A buss bar and each rack battery, I put a 2P 300A MCCB breaker between the buss bars and the terminal blocks supplying the two inverters so I have a single breaker handle that will cut all DC battery power in one device, and I put 300A T-class fuses between each inverter-positive and the terminal blocks.
On the PV side I put DC fuses on each string, an Exterior Disconnect that cuts off all PV to the building, and Interior Fused Disconnect between the Inverters and the incoming PV. I followed all the CEC (similar to the NEC you guys have) for grounding of the PV system and fusing. The only item I am not 100% sure of is the required DC Arc-Fault detection/interruption which is not a simple breaker you can buy like AC AFDD. DC arc-fault is hard to find, and generally we mostly rely on the Inverter to have this internally. Does it? and is it compliant? not sure. I asked the folks at Tomzn (who supplied my MCCB's) if they had or could come up with a DC rated AFDD DIN-rail mounted breaker for a combiner box mounting between the inverters and the PV - guess we will see.
Goboatingnow
Solar Enthusiast
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Google throws up several arc fault devices
Sanwizard
Solar Wizard
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You can build your own combiner box if you like. Very inexpensive using Aliexpress and home depot parts.
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OffGridForGood
Catch, make or grow everything you can.
DC rated?
if so please share!
OffGridForGood
Catch, make or grow everything you can.
yes, however did you ever find an AFDD DC-Rated breaker? The AC-Rated ones are very common as these are required for bedroom plugs etc, but DC and AC are not equal and (I am told) not available. Tomzn design and make breakers for a living, and were unable to offer a DC-rated Arc-Fault Detection Disconnect breaker to meet NEC 690.11 (we have similar requirement in Canada under CEC 64-216)
OffGridForGood
Catch, make or grow everything you can.
For those who have the SMA sunny boy units, you may be protected already - see article from SMA on their approch to NEC 690.11 compliance.
I have seen references to Eton and Schneider DC-rated AFDD breakers, but have been unable to actually source any. If you know where to get them speak up i am all ears.
I have seen references to Eton and Schneider DC-rated AFDD breakers, but have been unable to actually source any. If you know where to get them speak up i am all ears.
Sanwizard
Solar Wizard
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Looks like midnight solar may have a solution. https://www.altestore.com/store/enc...c-gfp-63-amp-dc-ground-fault-protector-p2413/
OffGridForGood
Catch, make or grow everything you can.
A ground faul - short to ground is not the same as as Arc Fault: ie detection of an arcing current jump either in series (pos to pos) or parallel between pos/neg.
The Arc Fault detector is intended to monitor changes in the current to detect an arc, and shut down the circuit if detected.
Say you install your PV system and later some rodent chews through the insulation of the pos and neg wires, and an arc starts to jump between these lines on your roof. It has been show that this type of 'leakage' often does not increase the current in the circuit but at the point of the arc high heat is generated and can cause a fire.
Another example, say you didn't crimp one of the MC4 connectors very well, and later the wire pulls out of the MC4 furrel a bit, not enough to break the circuit, but enough that the current jumps (arcs) from the end of the wire to the MC4 furrel, again not raising the amperage, but generating excessive heat and causing a fire.
The purpose of the arc fault detection and disconnect is to sense for these arcs and when detected shut down the circuit.
Here is a 2-minute video from Eaton to explain:
Yeah I was not able to actually get one.
Tell me how the DC arc fault circuit can protect against a + to - arc fault from the array??? Or any arc fault in the array?
The wire arcs, the inverter turns off, and the wire keeps on arcing because it's sourced from the panels.
I must be missing something.
If there is a DC relay to the array, I can see how it could stop an arc to ground fault by opening the relay....
The wire arcs, the inverter turns off, and the wire keeps on arcing because it's sourced from the panels.
I must be missing something.
If there is a DC relay to the array, I can see how it could stop an arc to ground fault by opening the relay....
Sanwizard
Solar Wizard
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I thought most newer panels are fused.
OffGridForGood
Catch, make or grow everything you can.
If i am reading the regulation correctly, the Arc Fault breaker is 2P and will cut both pos and neg, so the arc would stop, whether series or parallel arc.
OffGridForGood
Catch, make or grow everything you can.
a fuse will not do anything if the current doesn't rise above the fuse rating. I have been watching some of these lab tests and they show in some cases the current drops! during an arcing situation, and the fuses do not cut the circuit. This seems to be the reason for this requirement.
I live in fire country (everywhere these days?) So I'm building a concrete shed to put my inverters and batteries in. Primarily to protect them from a wildfire (along with routine maintenance of brush), but also to avoid risk of any fire from this equipment as well.
Maybe I'll even order some extra panels and wiring to keep in the shed. If everything else burns down, I can throw 4 to 6 extra panels on top / near the shed and have power
Maybe I'll even order some extra panels and wiring to keep in the shed. If everything else burns down, I can throw 4 to 6 extra panels on top / near the shed and have power
teal95
Solar Enthusiast
For tying the trailer down just pour a nice concrete parking pad for it that has a couple of tie downs cast in.
