My daughter and her husband built a new home a few years back. During the design process, I suggested to my daughter that she ask the electrical subcontractor whether a 400 amp service panel would be a good idea, considering the fact that the home would be a 4,500 sq ft, 3-story (small, tight lot) with a finished basement and 3-zoned HVAC units. The subcontractor assured her that a 200 amp service panel would be more than enough to meet their current and future needs.
Beautiful house, Sheldon! It must have been a bit painful to let it go.
I owned a Georgian Colonial (built in 1928) in New Jersey for almost 20 years. Lived in it for about 12 years. My late wife and I spent about eight years rehabbing most of the house, inside and out. I sold it when I moved to Wyoming in late 2019. I still miss it sometimes.
Just in case you’re curious, a slide show of the work in progress is here:
All my before and during photos are 35mm prints that have never been digitized. Four photo albums worth.
Let’s just say my before and during was similar to yours.
We lived in that house for 23 years, finished raising 5 kids, and then helped raise some of the grand children.
We received several awards and the house was featured on the HGTV program Restore America in 2003.
It was the adventure of a lifetime, now on to new adventures, like more time for model trains.
The new, down sized, one floor retirement spot actually has a larger space for trains than the big Queen Anne.
My train room at the Queen Anne was 1,000 sq ft above the garage. At the new (built in 1964) house, I have a 1,500 sq ft basement with very little in the way.
Why is that? How many watts was she planning on using in her house…?
If the discussion about panels was in terms of watts, she may have been able to figure that out for herself without carry around an algebraic equation in her head.[:D]
You should stop focusing on watts for household electrical requirements.
Think amps. Again, a 15 amp circuit delivers 1800 watts, while a 20 amp circuit delivers 2400 watts.
One other thing that may not have been mentioned is that recommended usage of a circuit is limited to 80% of capacity. So, on a 15 amp circuit, 1800 watts, you want to limit usage to 1440 watts. On a 20 amp circuit, 2400 watts, you want to limit usage to 1920 watts. Another way to look at that is to realize that those circuits are designed to provide 125% of available power to prevent overloads, if you limit usage to 80% of capacity (100%/80%).
Also, as has been pointed out, a 200 amp panel is not limited, say, to ten 20 amp circuits. If there is space on the panel for, say, 40 breakers, you could install forty 20 amp breakers (800 amps of electrical power) because not that much power would be in use at one time.
The reason that I told my daughter to inquire about a 400 amp panel was mostly out of curiosity because it would add so much more flexibility in distributing power throughout the 3-story house, finished basement, and 3-car garage.
And, as homes get larger and more complex, sub panels strategically located are a good idea rather than bringing all circuits back to a central location.
Additionally, I wired the Queen Anne with three wire twin circuits where two circuits on opposite poles of the panel share one neutral wire. This will almost cut in half the number cables going into the panel.
Again, 200 amps is plenty for most houses, it is all about proper distribution.
Nobody said or suggested that you can load up three outlets in a room with 45 amps of usage.
Let’s say that in that room with 3 outlets, all 3 outlets are wired to a 15 amp breaker in the service panel, and those are the only 3 outlets on that circuit. You would be limited to 1800 watts (1440 watts at 80%) plugged into those 3 outlets.
Moreover, since extension cords and multi-plugs are always discouraged, it would be best to plug in two lamps, or whatever, to each duplex outlet for a total of 6 lamps, or whatever, that are being plugged in.
So, for example, if each lamp holds a 100 watt bulb, you would only be using 600 watts on that individual circuit. If each bulb holds a 200 watt bulb, you would be using as much as 1200 watts, nearing the safe capacity (1440 watts) of that circuit.
My friend in Golden Gate Estates had an aoutbuilding built and electricity run to it.
The diagram shows how it is wired, and it looks wrong to me. I understand the 60 amp breaker divides up the flow into two circuits, but is each limited to 30 amps? If not, wouldn’t the 10 gauge wire be too small?
Also, should the white (neutral) wire be larger than the other two since it is the return for both circuits and could have 60 amps current flow? Should there be a parallel 10 gauge white wire. Or, since the white and green both connect to the ground bar is this OK?
What about the ground, should it be isolated since it is a seperate sub panel?
Or, is this OK, and I just don’t fully understand residential wiring?
Tesla chargers require something like a 60 amp circuit. Once you work out the load and everything, there’s a pretty good chance that you need an upgrade.
Kevin are you sure about the wire gauge? For a 60A breaker it should be much larger, #6.
But the connections are correct and the neutral needs only be the same size as the hot wires. The two hot phases are out of phase to each other, that is how you get both 240 volts and 120 volts from the three wires.
Hot to hot is 240 volts, either hot to neutral is 120 volts.
The load on the neutral will never exceed the the highest load on one hot phase. The current flow on the neutral caused by “black” is canceled out by the opposite current flow on “red”.
As I explained above, two 120 volt circuits can share a neutral as long as each is on a different hot.
Sounds like somebody set that outbuilding up for a 30 amp breaker, and then up sized the breaker after the fact. Not good.
if this is an ‘outbuilding’ shouldn’t there be a honkin’ ground rod right there where white and ground are bridged? Really deep and perhaps tested in different weathers to make sure it is properly connected for ‘telluric currents’ as it were?
is the ‘sub panel’ wired simply with two outlets, wired red to white and black to white respectively? Because even with a 30A breaker I don’t see that limiting one side to 15A before it trips, and that could cause trouble in the outlet structure and contacts if ‘only’ residential cheap grade outlets were used for a price.
If that is a sub panel, I’d have two breakers for the outlet branches in there, each sized ‘sensibly’ (e.g. 20A if you are going to plug 'outdoor power equipment) in to use) and wire the outlets to them accordingly. That is no different from house wiring using a master 240V breaker and 120V branch breakers, where the latter correctly trip on overload regardless of 240V phase…
Then he keeps his 60A breaker, spends the money to ‘replace’ it on the two new 15A 120V breakers, and has safe capacity to add two more branches to the sub panel if he wants them.
I suppose I’ll throw this out there too, since I’m in the process of refinishing my basement to turn it into a den and train room. I do want to have a subpanel installed and I’m smart enough to know when I’m out of my depth, so that’s something I’ll call in the professionals for.
One of the things that’s sort of got me perplexed is the grounding electrode. Does this influence the actual location of my subpanel? I’ve got a spot picked out where I’d like to go, but don’t know how that, or if, the grounding provisions might make me have to change my plans.
The sub panel does not get its own ground rod. It needs a ground wire separate from the neutral back to the main panel. Like Kevins drawing above.
In your main panel the neutral is bonded to the panel can and the ground conections, but in the sub panel the neutral must remain separate from the ground connections.
Yes, as a sparate building it should have a ground rod, but that is a minor issue. The 2P 60A breaker provides 60 amps at 240 volts, the wire size is too small - period.
No matter what it is connected to, the #10 wire is not protected.
Yes one might assume it is feeding a small panel of just 2 or 4 breakers. But if thats all the power that was needed a 12/3+G could have provided two 20A circuits using two 1P-20A breakers or a 2P-20A breaker depending on how your friendly inspector interprets the code.
