New construction wiring question

[hockeypuck]

We just built a home in Wisconsin and I found out that all sub panels must be grounded to their own ground rod. Also, they must be accessible. Just our experience with our locale. Good Luck! The Baron

Sounds like you have a building inspector who does not know the NEC 2005 code. A piece of SER wire (4 wires total) going from the main panel to the subpanel will suffice NEC requirements. You just have to make sure you seperate your grounds and neutrals in the subpanel.

puck

 

[Inspector507]

Sounds like you have a building inspector who does not know the NEC 2005 code. A piece of SER wire (4 wires total) going from the main panel to the subpanel will suffice NEC requirements. You just have to make sure you seperate your grounds and neutrals in the subpanel.

puck

But? Were the subpanels installed in a remote building? If they were, the inspector was correct. If installed in the main building, not correct.

 

[BobRip]

In absence of a subpanel, some of my circuit runs would be upwards of 100' feet away.

Runs of 100 feet can cause excessive voltage drop or require the wire to be increased in size.

There are restrictions on locations. I had one in a clothes closet and the county made me put up separation walls. You also cannot put them in a bathroom. There may be other restrictions. Check with your local inspector.

 

[SPIKER]

any separate building requires it's OWN ground rod... the sub panel does not if in same building but requires 4 wires run to it, 2 hots 1 neutral and one ground, the sub panel requires that the neutral not be bonded to the panel box which is where the ground bus would be attached. if running a sub panel out to a different building then you put in a a ground rod for that building tie the new ground rod to the sub panel box's ground bus. do not tie the neutral bus to the ground bus in this sub panel. (this is for running 3 wires, 2 hots and one neutral ) would not be required to run 4 wires to separate out building in this case.


(I think this is correct for NEC, but have not done this type of work for 2 yrs now. moved to industrial electrical equipment...


makr M

 

[5030tinkerer]

Point of clarification: There is about 1600 sqft on the second level. The main level is another 1600 sqft or so and the foundation level is 2200 square feet. All levels of the home use ICF. It's a big house for only one main panel.

 

[MossRoad]

If the reason you want sub panels is to save on wiring costs and/or reduce voltage drops, those are probably good reasons to consider them.

However, if the reason you are considering sub-panels is for ease of resetting breakers without having to go to the main box... I can count on one hand the number of times I have blown a breaker in my life. Almost all of them were due to me touching two wires together while working on some bench project or appliance that I was testing. In our current house, the previous owner wired 29 overhead lights, the bathroom fan, the range hood and two bathroom outlets to one 15 amp circuit. My wife blew it with the bathroom fan, lights and a blow dryer. I have since split that circuit into several. That is the only one that I can ever recall overloading in my life.

If you are blowing breakers so often that you want to put sub-panels in a more convenient location, you need to increase the number of circuits and decrease the number of items using each circuit, not make it easier to reset them. I think the trip to the circuit breaker panel is like a penance march for doing something wrong... you should take the time to contemplate your wrong doing and think of a way to correct it.

 

[_RaT_]

If the reason you want sub panels is to save on wiring costs and/or reduce voltage drops, those are probably good reasons to consider them.

However, if the reason you are considering sub-panels is for ease of resetting breakers without having to go to the main box... I can count on one hand the number of times I have blown a breaker in my life. Almost all of them were due to me touching two wires together while working on some bench project or appliance that I was testing. In our current house, the previous owner wired 29 overhead lights, the bathroom fan, the range hood and two bathroom outlets to one 15 amp circuit. My wife blew it with the bathroom fan, lights and a blow dryer. I have since split that circuit into several. That is the only one that I can ever recall overloading in my life.

If you are blowing breakers so often that you want to put sub-panels in a more convenient location, you need to increase the number of circuits and decrease the number of items using each circuit, not make it easier to reset them. I think the trip to the circuit breaker panel is like a penance march for doing something wrong... you should take the time to contemplate your wrong doing and think of a way to correct it.

Moss, you don't run a table saw do you? A small portable compressor will trip 15 amp and even 20 amp breakers in a heartbeat when they are cold. Of course, those typically are more shop related.

 

[chipsndust]

Maybe someone with more wiring experience can confirm this.
I think the sub-panel must have a lower rating than the main? For example, if your main service is 100A, the sub-panel would have to be 60A. Your total load can't exceed the rating of the service coming into the main from the utility. Plus, a fault on a subpanel circuit could take out the Main.

 

[Dusty]

I have a sub panel on the second floor of the house that serves an addition to the home, one in the garage that services the new garage addition, and one more next to the 200 amp main panel in the cellar for expansion. The 42 breaker main box is full! When I built the home, I broke out the lighting in each room to be on one breaker and the wall plugs to be on another breaker. The bathrooms were also broken up, so no matter what breaker was to trip, you would never be in the dark in that room. I didn't install a wire chase until later on, while doing a addition, but a wire chase to the attic is a good idea. Today, I would have 3 or 4 runs from the basement to the attic using 2" PVC pipe for any future expansion. The one thing that I did make a mistake on, was the telephone and cable installation. If I were to do it over, I would do home runs back to the point of origin for all of these. That way, you can make any changes later on without much effort. I did install a direct wire for my computer cable connection when I added the addition. The cable company supplied me the wire and said that when it was compete, that they would come back and install the ends on the wires. They left me enough wire to also do home runs for all the rooms televisions, if I wanted. Still haven't been motivated enough to do that project. We only use one TV for the most part, so it isn't high on the list. Take lots of pictures and have a tape measure in them showing the distance from the floor or wall, so nothing gets lost in the walls. I have one wire that comes to the main panel that was never marked, and never hooked into the panel, because I have never figured out where it goes. I think that one of the fellows that was helping me run the wires, just threw it into the bundle of Romex to mess with me. Some day, I will follow it back to where it disappears in the wall and give it a tug. My bet is that at the other end, 2 feet of wire will pull out of the hole in the floor where it goes up.
If you are going to have any concrete, block, or brick walls, make sure to provide for an extra switch in the box for later on.
The one thing that I did was to put flood lights all around the house that go on from either the kitchen or the master bedroom. If you hear a noise outside in the middle of the night, it is good to be able to flood the area with light to see what is going on. My wife loves that feature when I am away. Keeps them lit till daylight.
Dusty

 

[MossRoad]

Moss, you don't run a table saw do you? A small portable compressor will trip 15 amp and even 20 amp breakers in a heartbeat when they are cold. Of course, those typically are more shop related.

My compressor has never tripped my 20's. It's 1.5 or 2 HP, can't recall. It has capacitor and unloader for easy starting. Same thing for my table saw (except for the unloader, of course).

 

[JimR]

We just built a home in Wisconsin and I found out that all sub panels must be grounded to their own ground rod. Also, they must be accessible. Just our experience with our locale. Good Luck! The Baron

I can see grounding a sub panel if it is in an out building or such. But to ground a sub panel on the second floor of a house that is already grounded through the main panel seems to be useless.

 

[_RaT_]

My compressor has never tripped my 20's. It's 1.5 or 2 HP, can't recall. It has capacitor and unloader for easy starting. Same thing for my table saw (except for the unloader, of course).

My table saw trips not on start but when ripping. A wet piece of lumber that starts pinching the blade and the load goes up so fast I can't do anything short of let it trip. My 3HP Unisaw does not trip the breaker but has on a few occasions hit the thermal limit on the motor. My litle Emglo easily trips a breaker. I use synthetic oil and it does help on cold mornings.

 

[Dusty]

I can see grounding a sub panel if it is in an out building or such. But to ground a sub panel on the second floor of a house that is already grounded through the main panel seems to be useless.

The National Electrical Code requires that all panels past the main panel have to have the grounds and neutrals separated. I went through this last year having to separate out my grounds and neutrals in the former main panel, since I had a 200 amp main circuit breaker right after the meter, and then a master disconnect switch that is for the whole house generator. The neutrals all return back to the pole through the neutral wire supplied by the electric company, and all the bare ground wires are tied into ground rods on the way to the final ground at the well casing. The wire from the first sub panel (formerly the main panel) had to be one uninterrupted wire all the way back and hit each ground rod on the way. I find it easier to follow the code now, than have to deal with a home inspector in the future that feels that what I have is wrong and it holds up the house sale, or I have to pay someone to make the corrections before the closing. I know that we all believe that we will never sell the home, but I also realize that I won't live forever, and that at some time in the future, the home will be sold. If it is after I am gone, then doing it correctly now, will make it easier on whomever has to deal with my estate. If I am still alive when it comes time to sell, it will make it easier on me.
Dusty