Normally the main is on the top but you can install a service panel with the main on the bottom unless local codes prohibit it.
The panel and breaker have to be of the same manufacturer. This way the breaker will fit into the panel. If the panel has a push in bus bar, the breaker must also be the type to accept the bus bar. If the bus bars in the panel are of the bolt in type then the breaker also has to be a bolt in breaker.
No, a Cutler Hammer will not work in a GE panel or vice versa.
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.
A 100-A sub-panel would be fed from a 100-A breaker.
Most of the breakers in a panel will be 120 VAC. Double height breakers are 240 VAC. A triple height breaker probably indicates you have 3-phase power in the panel.
Normally the main is on the top but you can install a service panel with the main on the bottom unless local codes prohibit it.
The panel and breaker have to be of the same manufacturer. This way the breaker will fit into the panel. If the panel has a push in bus bar, the breaker must also be the type to accept the bus bar. If the bus bars in the panel are of the bolt in type then the breaker also has to be a bolt in breaker.
It is inserting a breaker into a service panel.
only if listed in the panel board
No, a Cutler Hammer will not work in a GE panel or vice versa.
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.
A 100-A sub-panel would be fed from a 100-A breaker.
If you are talking about a breaker in a house panel then a 15 amp breaker would be used. It is the smallest amperage breaker that you will find in a house panel.
Possibly. Depends on which model Siemens breaker you have.
The biggest circuit breaker in any home is the main breaker located in your main breaker panel that is installed where your electrical service cable comes into your home.
I know of no code restrictions on making a panel movable except that the panel must be accessible, meaning not requiring the removal of anything to get to it, and no breaker can be higher than 6' 7''. That pretty much eliminates the possibility of doing what you ask.