For your protection, yes, it should be inspected
Not exactly sure what your question is and you need to make sure you are in compliance with electrical code for your jurisdiction. But, generally speaking you install a large breaker (let's say 100A 2 pole breaker to power the sub panel) just as you would install any other breaker in the presently used (hot) panel, and the proper sized cable then goes from old to new and terminates on the main lugs of the new panel. Ground and neutral are usually isolated from each other in the sub panel but depends on other factors as to location of the sub panel, etc.
If the sub panel is in the same building remove the bonding screw that bonds the neutral bar to the panels enclosure. Remove the ground from the second ground rod. The sub panel is grounded by the ground wire from the sub panel's feeder. If the panel is separate from the main building treat the sub panel as a separate service. It will need its own ground rods and ground wire from the rods to the neutral bar of the sub panel. Leave the bonding screw in. There will be no ground wire in the conduit between the two services.
Depending on how many breakers you have in your exisiting panel if you only have a old 6 or 8 circuit panel then I would suggest a new panel, In the newer building world where you have a 20 or 30 circuit panel then I would suggest a sub panel.
That would depend upon how many amps will be used in the sub-panel. For example, a 30-A subpanel would need a minimum of 10 AWG feeder conductors.
First you need to determine if addition of the new breakers will exceed the 200A service under normal operating conditions. If so you will need to go to power company and increase service and put in a larger main panel. If you have the capacity for the extra current you can add a sub-panel and add the breakers there as well as the breakers you will remove from main panel to accommodate the sub-panel breaker. Another way depends on what breakers are in current panel. There are some breakers that can be duplexed in the same space as a single breaker.
You have two options, one is a complete service change. The average house service these days is 200 amps 42 circuits. The second option is to install a sub panel off the existing service. Depending on how many circuits you need will govern the size the sub panel. Here is where it gets tricky. Two side by side single pole breakers or one two pole breaker will have to be removed from the original service panel and replaced with a new two pole breaker. The size of this breaker will be governed by the total load of the new sub panel. The wire from the new sub panel to the two pole breaker is also governed by the load of the sub panel. As an electrician I would recommend that you not do it yourself but get a qualified electrician to do it for you. He would (should) take a permit out for the job and get it inspected.
Not exactly sure what your question is and you need to make sure you are in compliance with electrical code for your jurisdiction. But, generally speaking you install a large breaker (let's say 100A 2 pole breaker to power the sub panel) just as you would install any other breaker in the presently used (hot) panel, and the proper sized cable then goes from old to new and terminates on the main lugs of the new panel. Ground and neutral are usually isolated from each other in the sub panel but depends on other factors as to location of the sub panel, etc.
The size of the sub panel is dependant on the amount of connected loads and the amperage of these loads, or the total load in amps on how many new circuits that you will require.
If the sub panel is in the same building remove the bonding screw that bonds the neutral bar to the panels enclosure. Remove the ground from the second ground rod. The sub panel is grounded by the ground wire from the sub panel's feeder. If the panel is separate from the main building treat the sub panel as a separate service. It will need its own ground rods and ground wire from the rods to the neutral bar of the sub panel. Leave the bonding screw in. There will be no ground wire in the conduit between the two services.
Depending on how many breakers you have in your exisiting panel if you only have a old 6 or 8 circuit panel then I would suggest a new panel, In the newer building world where you have a 20 or 30 circuit panel then I would suggest a sub panel.
The sub-panel need to be fed from the main panel, by way of a circuit breaker connected to one of the breaker locations. Or if your sub-panel has a main breaker installed you can feed from the main panel with a sub-feed lug kit. This looks like a breaker, but is only a point where you can branch off the sub panel.
That would depend upon how many amps will be used in the sub-panel. For example, a 30-A subpanel would need a minimum of 10 AWG feeder conductors.
Yes
yes. But this is not a handyman level project. It is suggested you "Call a pro." What you're looking for is not another "main breaker" but a "sub-panel" that is fed by a "feeder" cable from the main panel. Have your electrician calculate the load you'll need in the out-building, then design and install a new feeder circuit and sub-panel for it.
First you need to determine if addition of the new breakers will exceed the 200A service under normal operating conditions. If so you will need to go to power company and increase service and put in a larger main panel. If you have the capacity for the extra current you can add a sub-panel and add the breakers there as well as the breakers you will remove from main panel to accommodate the sub-panel breaker. Another way depends on what breakers are in current panel. There are some breakers that can be duplexed in the same space as a single breaker.
Judging by your question I'm going to take a guess and say you should probably not attempt to do this yourself. Nor do I recommend it. That being said. You can either have your service upgraded to 200amp, and install a 100amp double pole breaker and branch it off into a 100 amp sub panel. You could most likely re-use your old panel for the 100 amp sub panel. Or... You could have your new 200 amp panel installed in a different location and your current panel wired into it for 100 amps.
you propaly can't sub panel from 100 amp panel. Just not enough amperage to be worth while. i had to up grade t a 200 amp main first and then I was able to take a 60 sub panel from that.