I'm adding a 100 amp sub panel for my basement shop. Also need some extra breakers for the attic addition.
I plan on removing the lower two circuits from the main panel and putting the 100 amp breaker there. The sub panel will be mounted immediately next to the main panel.
Sub panel will be fed by 2 AWG wire.
Question is how do I attach the Nuetral? The sub panel will be grounded to water service (same as main panel).
Is there room to fit the neutral in the 'square' at the top (with white wire) or at the bottom (with black wire) ? If there is, that's what I would do.
For sure, I would be consistent with your local codes, and be sure what you are doing fits the National Code. There have been recent changes having to do with neutral and ground requirements (2 outside ground rods at least several feet apart) and some box bonding requirements. Your box shown shows the ground buss bar is bonded to your box.
Play safe. [img]/forums/images/icons/grin.gif[/img]
[img]/forums/images/icons/smile.gif[/img] Hazmat......I just LOVE it when someone asks how to do something "right". Here is the answer to your question: A sub panel will need to have TWO neutral bars in it...... one neutral bar is actually grounded to the case of the sub panel, and one isn't. The neutral bar that is "floating" (not grounded to the case) is where you gather all of the white leads. The neutral bar that is grounded to the case of the sub panel is where the greens and the bares go. Then you run a heavy white lead to ANY SPOT on the neutral bus of the main panel; and it looks to me like there is enough diameter in some of those holes in the neutral bar to do that. DO NOT shove the white wire from the sub into that big square lug where the main ground of the main panel is now. THAT is about the most "Joe McGee" thing that you could do, and it is strictly against code. Then, you run a green lead.......and this can be a white wire with green tape on it.... to that same neutral bus. The MAIN PANEL is the only place where green and white go to the same bar. In all sub panels, they have to be separate bars; the bar for the white leads is "floating" and the bar for the green leads is connected to the panel case. Almost all sub panels have an optional grounding bar kit that you can install, and the bars will all have a screw that connects them to the case. If the bar that you have in the sub right now is connected to the case, remove that green screw. [img]/forums/images/icons/crazy.gif[/img]
[img]/forums/images/icons/tongue.gif[/img] Just a further note........ [img]/forums/images/icons/blush.gif[/img] You DO KNOW that the main panel that you have was never intended to have a "distribution" breaker installed in it that serves a sub? You do understand that? The panel that you have there is designed to have the load spread up and down over the whole distance, and was never designed to take 100 AMPS off of only two little bites on that bus. A "distribution panel" is a panel that serves sub panels and as such has bus that CAN handle large amounts of current with just two bites per breaker. You will most likely be OK here unless your workshop has a large compressor and air conditioning. In that case, there is a chance that the breaker bites could get kind of w-a-r-m. Electrical power transmission is a matter of how much "footprint" the connections have for the current to move across. [img]/forums/images/icons/tongue.gif[/img] Of course I'm paranoid about stuff like this having been in the infrared scanning business for years and years I have seen way too much ickky stuff[img]/forums/images/icons/crazy.gif[/img] [img]/forums/images/icons/frown.gif[/img] In my ramshackle farmhouse out here in the sticks I have a 200 AMP main DISTRIBUTION PANEL which feeds to three subs and to the shop with breakers for each one. [img]/forums/images/icons/cool.gif[/img]
Hazmat,
For your Neutral lug in the main panel, try to find an auxillary neutral lug kit(not a ground lug kit) from an electrical supply house that sells the brand that you have. That is what you need to connect the sub-panel's neutral in the main panel. DO NOT try to squeeze it in with another wire in any lug. The ground that needs to go to the sub-panel needs to be #8 copper or #6 aluminum and it will fit in any open lugs you have on the present neutral bar. DO NOT run a new ground to the water system, get it from the main panel.
You've got me a little worried about my 100amp feeder.
An air conditioner will be run off the sub panel for the attic (220V 20-30amp?). I also plan on adding a large circuit for a welding outlet or two (if & when I get a welder). Minimum 50amps possibly 60 or 100 amps.
Will I be in trouble if I'm welding and the A/C kicks in?
Would it be more appropriate to run a 60 amp feeder for the sub panel & squeze the welding circuit into the mail panel?
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