Wiring to my sub panel

[NHBandit]

First off I already tried doind a search and it only confused me more. Searching for things like "sub panel wiring" results in hundreds of threads that don't answer my simple question. So please bare with me and give me a simple laymans answer to my question. I have a 4 wire feeder wire coming into my sub panel in my detatched garage. I bought it at Lowes after reading several threads here about what to get and it's a 100 amp panel & it came with a couple 220 breakers and 3 110 breakers. Perfect for my needs. So today I'm wiring it up and there is no place to attatch the heavy bare ground wire. Pictures I've found on here and on Google show the neutral going to the large square spot on the ground bar so that's how I hooked it up. Do I need to go get another of those square adaptors and also attatch the ground to the same bar ? Also there was a green screw loose in the bottom of the box that could be used to ground that bar to the box itself. Do I want to do that or leave the box ungrounded ? Second question. I have a 100 amp breaker I bought for the main panel in the house and plenty of room for it. I have 400 amp service in the basement. When it comes time to hook up to the main panel do I also attatch the large ground wire from the garage to the neutral in the house as well ? Here is a pic of where I'm at. Thanks.

 

[matt151617]

You're doing it wrong. You need to buy a ground bar for that panel. The neutral and the ground must remain separate. They are only bonded in the main panel, so throw that green screw out.

You'll also need to install 2 ground rods, at least 6 feet apart connected to the subpanel with #6 copper.

What gauge is the wiring coming into the garage? Make sure that is protected with the proper breaker size in the main panel.

 

[Focke-Wulf190]

You look like you have a SQ-D panel? You need to purchase a ground buss for your panel & hook up the ground wires to it, also do not bond the neutral buss to the panel with the Green screw. You will need to drive a ground rod at the detached garage, & hook it to the ground buss. The neutral wires and ground wires are isolated from each other & the box is bonded to the ground buss. I hope this is helpful to you.

 

[Charles (in GA)]

Looks like both of the bars in that panel are connected with a strap across the top, mostly out of view behind the plastic. Those are neutral bars. You should have no green screw or strap or other connection from those bars to the shell of the panel.

See those holes punched in various places in the back of the panel shell, those are the holes where you run in the screws for the ground bar(s).

Look at the decal/placard on the inside of the door, it will give you the correct part number(s) of the various length ground bars that are allowed to be used in that panel. The hole spacing of the bar will align perfectly with the holes in the back wall of the panel. Both your bare aluminum ground and the copper ground attach to the ground bar. You may also need a large lug that attaches to the ground bar for the larger bare aluminum ground wire. That lug will, depending on the brand of panel, either have two ears that push into holes in the ground bar and the bars screws retain it, or will bolt on the top of the ground bar.

Again the placard on the door will give you part numbers and sizes of wire that will fit the various lugs and holes in the bars, along withe the number of wires of what sizes are allowed in one hole in the bar.

Charles

 

[NHBandit]

Thanks guys. I did manage to find a picture of the same Square D panel poking around on here and it shows that missing ground bar. I will get one. The ground coming from the ground rod is the bare copper wire you can see in the pic that's attatched to the bottom left side of the neutral bar. I now know that's not correct and I will remove it and attatch it to the new ground bar as soon as I get one. The green screw will end up in my junk drawer to be used for something else.