Sub Panel AGAIN

Everyonre tells me to run a sub panel to the other ened of my garage from the now exististing 200 amp main which is at the entrance of the garage.

What is the purpose of a sub when I altrady have all the neede slots availaible in the main??

John

 

If you still have plenty of space in your main panel, and if the distance to the new loads is not far and is in the same building, there is almost no reason for a subpanel.

Here are a few reasons for a subpanel, none of which seem to apply to you:

1. The number one reason for a residential subpanel is probably for wiring a detached structure. In all cases in which more than a small amount of power is needed, a subpanel is required for this application.
2. Probably the second most common reason for a residential subpanel is that you've run out of space in the main panel. In this case, the subpanel is often installed right next to the main.
3. If the power needs are a long ways from the main panel, a subpanel offers some ability to shut off the power with a shorter walk. This is common for such things as workshops where you might want to shut down the subpanel for local modifications, or for safety reasons when young children might get hurt.
4. For maintenance on large appliances, it is comforting (and sometimes code required) to have the power shutoff within sight of the appliance. A subpanel is one way to do that.
5. Again, if the power needs are a long ways from the main panel, a subpanel will have less voltage drop than multiple individual circuits.
6. A subpanel might offer an incremental way of upgrading a very old panel or very old wiring.

Anybody want to add to my list?

 

I was reading back on your other posts looking for where you asked about subpanels. In all the posts you said that is what you were going to use. I was trying to find the reference to when it was suggested by someone here, but I could not find it.

Anyway, why would I run a subpanel? Well, all of John's reasons are applicable. The main reason why I would run a subpanel in your situation is to save the money (and hassel) of running multiple circuits long distances individually. If you spend your money on a heavy feeder for your subpanel, you would save money on the wiring for that side of the garage. However, if your garage is not very long, this doesn't apply.

Mainly, I like to use table saws, welders, power tools, etc.... and need 220V outlets for them. So instead of running 3 heavy duty sets of wires for those tools, I can just run one to a subpanel and run the outlets a few feet from the subpanel. Saves me money on wire and offers a great deal of upgradeability/adaptability.