The chosen location (my shop) for my 2x6500ex is about 50 feet from my utility meter/main panel which is on my house. When running wire from the main to the 6500ex's for the grid connection, then back to the house for connection, do I calculate only one way ampacity distance for wire size, or is it both ways? Meaning, does the 6500ex take the voltage drop from the first distance to the AIO, and boost it internally so it's like I'm starting from a source location again at the AIO, or does the AIO strictly do a grid bypass through it so whatever voltage drop was already existing from the first distance now carries through on the second distance calculation for ampacity? I hope that made sense. thanks.
Grid wire ampacity calc. dist. to 6500ex's, 1 way or 2?
- Thread starter jfharper
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Ampacity and voltage drop are 2 different things. For voltage drop there are multiple cases you should consider, voltage drop on the whole circuit from the utility, thru the inverter, and to the house should be no more then 3% for the case power is passing thru inverter to load. Additionally you will want the feeds from the utility to inverter, and from the inverter to the house to be sized at no more then 2% voltage drop each to avoid inverter trips due the inverter having to raise it's output voltage above it's limits to compensate for the voltage drop.
Ampacity and wire size will need to be calculated based on loads adjusted ambient temperature, and derated if more then 3 current caring conductors are in the same conduit, and/or trench.
Ampacity and wire size will need to be calculated based on loads adjusted ambient temperature, and derated if more then 3 current caring conductors are in the same conduit, and/or trench.
timselectric
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It would be better to locate the 6500ex's at the house.
And let the higher voltage solar DC travel the distance.
Make the power, where you are using it.
And let the higher voltage solar DC travel the distance.
Make the power, where you are using it.
There will be a battery bank, so I wanted the fire risk at the shop which has concrete walls.
timselectric
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What type of battery?
LFP batteries are no more fire risk, than the wood studs in your house.
Good to know...rethinking pv wire to house instead.
Unfortunately, I don't have much room in my house for the equipment, sort of small home. Concerned about the noise from the inverters a bit, and anything that might fail associated with the equipment, like inverters or surge arrestors, etc. and cause fire. So, I maybe looking at building a small utility room on my house next to the main panel, which would be a cost. So, either spend on the utility room or the AC wire and go at the shop....having trouble deciding....or setup some sort of CO2 suppression system...
timselectric
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I can understand a concern for noise. (The cooling fans)
But there's no extra fire risk. It's just circuit boards in a box. No different than a TV or computer.
But there's no extra fire risk. It's just circuit boards in a box. No different than a TV or computer.
I’m having to rethink putting the inverters at the shop. After measuring (I ball parked initially) I got 100 feet between shop and main panel at meter.
I ran thru the calc pvgirl mention and 4 awg would meet the factors she mention, except for derating. I’m stuck on that. I am going to have 4 6500ex inverters total, 2 sets of 2 running split phase.
1 set will feed the house 100feet away, so that’s 3 #4awg wires ac out.
The other set will feed the shop and well pumps…wire already there for that, and the stove back at the house…there is #8 already in the ground from shop to house.
I would also like to feed the inverters with AC IN via 3 #4awg for each set.
I am pretty sure I can run 9 #4 in 1-1/2” conduit…unless the parallel circuit thing, which I don’t get yet, messes that up.
As far as derating, i think I take the 90 degree C column which is 95amps and derating 70% for 9 ccc which is 66.5amps. I used 55 amps for the voltage drop at 100 feet and was ok at 2% round trip (200ft) or 3% each way (100ft). So I think I’m ok…can someone confirm?
Lastly, since there is already a #8 ground wire running back to the main panel, would I need to run any addition ground wires back to the main…can I just ground things at the shop and let the one #8 ground handle the faults.
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Ok, after studying this a bit more I see the challenges with wire costs at that length, derating, running a shared neutral same awg as hot per set is a bad idea. Now I see why it may be better to do the utility room. Just some challenges with that too because it will be small and heat inside will be a concern unless I run an air conditioner, etc.
Is this the Output Voltage Regulation spec in the manual: 120Vac+-5%?
This is something that I've wondered about. If you have an inverter that's some distance from the main panel, and a subpanel that's near the main panel, can use a single neutral to the inverter, so there's just a pair of hot going to the inverter, a pair of hot coming back, and a single shared neutral (and a ground, of course)? It seems like it ought to be okay if the subpanel gets it's neutral from the main panel, but it's easy to overlook something.
timselectric
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Technically it would be fine, if they are all in the same conduit. But it would be hard getting an inspector to sign off on it.
