I would tend to agree with "Tripleauto". If you do not disconnect the electrical supply to the house, you run the risk of having 240 volts at up to about 75 KVA coursing through your body. Needless to say, before the transformer blows out or someone cuts off the power, your corpse will be mostly ash. Call the power company to co-ordinate having the power turned off while you or your electrician do the work. Once the power is off, swapping out the main breaker is a relatively simple job, assuming you can find an exact replacement. If there is no exact replacement, as in the panel is fairly old and the breaker is no longer available, you will end up having to replace the whole panel or add a 125 amp breaker in a separate enclosure in an accessible location between the meter socket and the breaker box, preferably within reach of the breaker panel. The International Residential Code requires a disconnct where there are more than six breakers needed to turn off all power to the dwelling. Check with your local Building Code office before doing anything.
--Peter Nomikos, International Code Council Master Code Professional Building and Zoning Director, City of Mauldin, SC
I dont mean this to sound arrogant. but if you have to ask you might be best to have a professional to do it. the wires coming into the box will be hot without being able to pull meter off of house to disconnect. the panel has to come off and many are different
Answers & Comments
I would tend to agree with "Tripleauto". If you do not disconnect the electrical supply to the house, you run the risk of having 240 volts at up to about 75 KVA coursing through your body. Needless to say, before the transformer blows out or someone cuts off the power, your corpse will be mostly ash. Call the power company to co-ordinate having the power turned off while you or your electrician do the work. Once the power is off, swapping out the main breaker is a relatively simple job, assuming you can find an exact replacement. If there is no exact replacement, as in the panel is fairly old and the breaker is no longer available, you will end up having to replace the whole panel or add a 125 amp breaker in a separate enclosure in an accessible location between the meter socket and the breaker box, preferably within reach of the breaker panel. The International Residential Code requires a disconnct where there are more than six breakers needed to turn off all power to the dwelling. Check with your local Building Code office before doing anything.
--Peter Nomikos, International Code Council Master Code Professional
Building and Zoning Director, City of Mauldin, SC
I dont mean this to sound arrogant. but if you have to ask you might be best to have a professional to do it. the wires coming into the box will be hot without being able to pull meter off of house to disconnect. the panel has to come off and many are different