Building a new house -- What would you use?

[Supervstech]

Wow,

I am far from an expert on any of this, but I am 8 months in to building a house and this is what I did.

1900 ft upstairs 100% spray foamed
1100 walk out basement, ICF foundation

I wanted to power the whole house, grid tied. Indiana gives zip for selling power, so I skipped it.

Solark 15k runs one 200 amp panel
400 amp service
2nd 200 amp panel is mostly non essential 220 and a few random 110 circuits.

My electricians installed it all for 5-6 hours. Fully inspected and bought off

30 kWhr server rack

South and SW standing seam room will have 20 450 panels. I may add 8 more in a ground mount. I do not get sun until 10:30 in the summer. Winter will be shaded through leafless trees. Again I am no expert, but my experience is similar to yours. Fire away!!

Wow… That is a lot of SER cable. I’m more a fan of conduit, and wire way gutters.

Nice switchgear wiring layout.

 

[Hedges]

Would that be 4/0 aluminum 3 conductor plus ground?
Must be a bear to bend into place. But nothing like pulling through conduit, and can be backed out of the box to leave just the length needed for connections. The fine strand we use for batteries is so much easier to handle.

I'm going to put a box/gutter after service disconnect breaker (with Polaris) and fan out to a couple sub panels + PV disconnect. One 200A panel, will feed 2/0 (or larger? Ampacity/temperature for terminals) copper through Polaris into service disconnect. Box with nipple or elbows to panels should be easier than just conduit.

Where your one wire splits to two in the box, all same gauge. Is there a single 200A breaker at the meter, providing disconnect and OCP for SolArk as well? (You mentioned 400A service, it just feed something else as well.)


Square D now has 200A branch breakers (at least for QO if not Homeline). But unfortunately interlock kits don't work with those, they are 4-gang with handle in the middle. Would be a convenient and reasonably economical alternative to external transfer switch, what I do for lower amperage.

 

[Supervstech]

Would that be 4/0 aluminum 3 conductor plus ground?
Must be a bear to bend into place. But nothing like pulling through conduit, and can be backed out of the box to leave just the length needed for connections. The fine strand we use for batteries is so much easier to handle.

I'm going to put a box/gutter after service disconnect breaker (with Polaris) and fan out to a couple sub panels + PV disconnect. One 200A panel, will feed 2/0 (or larger? Ampacity/temperature for terminals) copper through Polaris into service disconnect. Box with nipple or elbows to panels should be easier than just conduit.

Where your one wire splits to two in the box, all same gauge. Is there a single 200A breaker at the meter, providing disconnect and OCP for SolArk as well? (You mentioned 400A service, it just feed something else as well.)


Square D now has 200A branch breakers (at least for QO if not Homeline). But unfortunately interlock kits don't work with those, they are 4-gang with handle in the middle. Would be a convenient and reasonably economical alternative to external transfer switch, what I do for lower amperage.

Nah, I work with it all the time.
4/0AL is so light and other than tight bends is easy to handle.

 

[Hedges]

What is the official word on wire temperature to use in ampacity charts, where a wire goes to a terminal of breaker with 75C rating?
I wish I could use 90C rating for 3 wires in cable or conduit, e.g. 2/0 copper good for 195A round up to 200A breaker.
Then in breaker panel call it wires in free air because no longer bundled, 2/0 ampacity 260A at 75C, so OK for 200A breaker.

In a breaker panel it could have one wire diameter clearance, but box isn't well ventilated and thermal breakers are heat generating devices.

Is the 90C rating only useful to allow derating (for more than 3 wires, high ambient temperature, etc.) but doesn't actually give current it is allowed to carry? Do I have to use 75C ampacity everywhere (unless it goes to a 90C terminal)?

Cerrowire Resources - Ampacity Charts

Ampacity is the maximum current that a conductor can carry continuously under the conditions of use without exceeding its temperature rating. Cerrowire's ampacity chart helps calculate the load requirement for a circuit.

www.cerrowire.com

What is "Free Air"?

Definition of "Free Air" in Ampacity Tables - IEEE (electrical) Code Issues - Eng-Tips

For NEC Table 310-17, what is the definition of free air ? A major manufacturer of motor control equipment has sized conductors to motor starters inside enclosu

www.eng-tips.com

Wire Size Chart for Conductors in Free Air

Wire Size Chart: Allowable Ampacities of Conductors in Free Air - 30C

wiresizecalculator.net

 

[hautions11]

It is Al, tough to bend the radiuses we had. There are 2 disconnects outside.

 

[Supervstech]

What is the official word on wire temperature to use in ampacity charts, where a wire goes to a terminal of breaker with 75C rating?
I wish I could use 90C rating for 3 wires in cable or conduit, e.g. 2/0 copper good for 195A round up to 200A breaker.
Then in breaker panel call it wires in free air because no longer bundled, 2/0 ampacity 260A at 75C, so OK for 200A breaker.

In a breaker panel it could have one wire diameter clearance, but box isn't well ventilated and thermal breakers are heat generating devices.

Is the 90C rating only useful to allow derating (for more than 3 wires, high ambient temperature, etc.) but doesn't actually give current it is allowed to carry? Do I have to use 75C ampacity everywhere (unless it goes to a 90C terminal)?

Cerrowire Resources - Ampacity Charts

Ampacity is the maximum current that a conductor can carry continuously under the conditions of use without exceeding its temperature rating. Cerrowire's ampacity chart helps calculate the load requirement for a circuit.

www.cerrowire.com

View attachment 154444

What is "Free Air"?

Definition of "Free Air" in Ampacity Tables - IEEE (electrical) Code Issues - Eng-Tips

For NEC Table 310-17, what is the definition of free air ? A major manufacturer of motor control equipment has sized conductors to motor starters inside enclosu

www.eng-tips.com

Wire Size Chart for Conductors in Free Air

Wire Size Chart: Allowable Ampacities of Conductors in Free Air - 30C

wiresizecalculator.net

View attachment 154445

I interpret it as a maximum insulation rating to allow for ampacity reduction in wireways etc.
In a residential setting 60C is the max allowed, due to the 10,000 aic breaker rating.

For solar equipment, I never go by the insulation rating, as heat is wasted energy.
Always best to go by voltage drop and shoot for lowest loss in the wiring.

 

[Supervstech]

It is Al, tough to bend the radiuses we had. There are 2 disconnects outside.

I use the wire bending tool for sharp radius bends.

 

[Hedges]

I interpret it as a maximum insulation rating to allow for ampacity reduction in wireways etc.
In a residential setting 60C is the max allowed, due to the 10,000 aic breaker rating.

I was thinking mostly about my AC wiring. PV DC, I'm pushing 30, 40 wires in a conduit so heavily derated.

Tables I copied above, 2/0 doesn't even show 60C rating for up to 3 conductors in a cable (other tables say 145A). But it does show 225A for 2/0, single conductor in free air.

For 200A service, e.g. overhead to meter to main panel, and to a sub-panel, I'd like to use 2/0 copper in 2" rigid conduit. That would be treating the individual wires inside box to breaker or meter terminals as "in free air". Do you know if that is an accepted interpretation/practice? Or am I supposed to use 4/0 for 200A?

I think you said to use 60C ampacity. But is that 60C from the 3-conductors table? (other tables say 195A for 4/0 awg)

Here's a table with the missing numbers:

4 Images Nec 2017 Wire Ampacity Table 310 16 And Review - Alqu Blog

We have collected all our best Nec 2017 Wire Ampacity Table 310 16 in one blog. These are our gallery collection about Nec 2017 Wire Ampacity Table 310 16. How to size a Cable Correctly Step-By-Step [Comprehensive Guide] Viewing a thread – How big of wire do I need? IMG_TITLE_7 Table 310 16 Nec...

alquilercastilloshinchables.info

 

[Madcodger]

Yes the Ronk bypasses the Solark if it has an issue. The large box on the right is just space to take the incomming service and split it. I have a picture.

I am setting up the batteries this week.

Other than the second panel, which I don't think I need for my situation, you've designed exactly what I have in mind for our new house. Great work! Allows you to take the inverter out of the picture and just rely on the grid for maintenance or if the inverter goes belly up. I think this should be the standard for any grid-connected system.

 

[Quattrohead]

I use the wire bending tool for sharp radius bends.

Knee

 

[hautions11]

Yes, I really don't need the second panel either. It is kind of future capacity. I have a 100 amp sub panel in the garage for future EV charger, small outbuilding in the backyard, etc. etc.

The hardest thing in building this house is planning for potential future stuff.

One other detail I left off. My hybrid water heater is wired in to the main panel and the back up 2500 watt resistence is in there too. You can tell the water heater to run hybrid only and it is 550 watts. Just my wife and I, that should work fine. Company comes, kids are over, run both hybrid and resistance. I also have a tempering tank that is un-powered. My geothermal cycles through that tank and during AC season, it heats most of your hot water through the tempering tank. That tank is a 50 gallon wound tank, Rheem Marathon.

 

[1201]

Yes the Ronk bypasses the Solark if it has an issue. The large box on the right is just space to take the incomming service and split it. I have a picture.

I am setting up the batteries this week.

Hi, where can I buy that large box on the right?

 

[hautions11]

My electricians brought it, I have no idea.

 

[hautions11]

They called it a tap box.

 

[1201]

They called it a tap box.

Thanks

 

[Hedges]

Places like Home Depot have some, this one's small 10 x 10

Southwire 10 in. W x 10 in. H x 4 in. D NEMA 1 Carbon Steel Indoor Screw Cover, Wall Mount Box, 1-Pack SC-10104-UPC - The Home Depot

The Indoor Screw cover is designed for use as a wiring and junction box. It is made of 16-gauge steel for durability. It has smooth, seamless sides in both the front and the back. Additionally, no gasket

www.homedepot.com

McMaster has many

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

Outdoor

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

 

[1201]

Places like Home Depot have some, this one's small 10 x 10

Southwire 10 in. W x 10 in. H x 4 in. D NEMA 1 Carbon Steel Indoor Screw Cover, Wall Mount Box, 1-Pack SC-10104-UPC - The Home Depot

The Indoor Screw cover is designed for use as a wiring and junction box. It is made of 16-gauge steel for durability. It has smooth, seamless sides in both the front and the back. Additionally, no gasket

www.homedepot.com

McMaster has many

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

Outdoor

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

Many thanks. I need to save this post somehow so I don't lose the links. Thanks!