Three or four would be normal. The total current should not exceed the rating of the main panel, so depending on how intensively the different circuits are used, more could be installed.
Yes, but only use them if absolutely necessary and I would never install more than one set of min-breakers in a service panel. Otherwise you can overload the panel.
The test button should only trip the GFCI. The fact that it is tripping two breakers indicates that somehow both breakers are feeding your GFCI circuit. I have seen this when there was a wiring error and two circuits were joined in an outlet that was connected to a breaker and through the GFCI outlet. To troubleshoot determine which outlets are effected when both breakers are off. Pull outlet from box and if there are two feeds remove one from outlet and run a toner on wire left on outlet to panel and one off outlet to panel. The GFCI could block the toner so if one side of the outlet does not tone back to panel check at GFCI. There must be two paths to your electric panel for the two breakers to trip and the GFCI may be faulty as well. Another way to check is to have the GFCI reset and both breakers on. Check each outlet that you have identified as being on GFCI noting that they can be in different rooms. With all outlets working turn off one of the tripped breakers. See if any outlets so off. If not turn off the other breaker and turn on the first breaker. If power is still present then the outlets are being fed by both breakers.
I wnt to install a tandem breaker but my panel box won't let me. Why?
None! Distribution panel designed to use specific type of circuit breakers. It's a NEC violation to install different type of breaker even it fits perfectly.
I once put out all circuits in a Hotel In Germany by plugging something in to an outlet in my room. If you are in a Condo there is probably a panel feeding your unit. Your problem might be there instead of the panel in your unit.
There are many ways one can install ge circuit breakers. One can install ge circuit breakers by turning off the power supply, removing the panel cover, testing it for power, and installing it by alining the breaker with the unused panel space.
Yes, but only use them if absolutely necessary and I would never install more than one set of min-breakers in a service panel. Otherwise you can overload the panel.
The test button should only trip the GFCI. The fact that it is tripping two breakers indicates that somehow both breakers are feeding your GFCI circuit. I have seen this when there was a wiring error and two circuits were joined in an outlet that was connected to a breaker and through the GFCI outlet. To troubleshoot determine which outlets are effected when both breakers are off. Pull outlet from box and if there are two feeds remove one from outlet and run a toner on wire left on outlet to panel and one off outlet to panel. The GFCI could block the toner so if one side of the outlet does not tone back to panel check at GFCI. There must be two paths to your electric panel for the two breakers to trip and the GFCI may be faulty as well. Another way to check is to have the GFCI reset and both breakers on. Check each outlet that you have identified as being on GFCI noting that they can be in different rooms. With all outlets working turn off one of the tripped breakers. See if any outlets so off. If not turn off the other breaker and turn on the first breaker. If power is still present then the outlets are being fed by both breakers.
I wnt to install a tandem breaker but my panel box won't let me. Why?
None! Distribution panel designed to use specific type of circuit breakers. It's a NEC violation to install different type of breaker even it fits perfectly.
I once put out all circuits in a Hotel In Germany by plugging something in to an outlet in my room. If you are in a Condo there is probably a panel feeding your unit. Your problem might be there instead of the panel in your unit.
It depends upon how many slots are in the panelboard. Divide this number by three and that will give you the amount of breakers that can be installed.What is the Amperage of the panel? Will these circuits all be running at the same time? There is space to allow (14) but there are a lot of other things to consider.
I would install a 60 amp sub-panel and use AWG #3 copper.
The panel schedule.
No, they will not work. Use only Murray breakers for safety.
The breaker panel. Breakers are placed in series with all outlets.
As long as the breakers are made to fit the box, there shouldn't be a problem. you can only use breakers listed for the panel, there should be a label on the panel door. It will list all of the breakers approved for use in that panel. If you don't see the breaker by manufacturer name listed, then it should not be used. Lots of brands will interchange, but they have to be listed to be approved.