The input lugs will still be hot and with some types of split bus panels the rails can still be hot. The disconnect only gurantees that no power gets out of the disconnect enclosure. There will always be hot stuff inside the enclosure.
translation for DUMMIES
When you shut off the main breaker there is still "HOT" power between the breaker and the outside of the house "Road Power" So the inside of where you want to install a new breaker is "DEAD"
Unless the panel is an older "Split Bus" panel as was explained. In that case, replacing any one of the 6 disconnect breakers is done "Live" and can be extremely dangerous!
Jim
I read today on the Underwriters Lab website that a main panel can be alive although the main circuit breaker is OFF. They did not elaborate.
How is that possible? When I turn the main circuit breaker to the house to OFF , all electricity is supposed to be OFF. Or not?
Don't forget about checking that the main breaker didn't "stick" when it is turned off.. This does happen from thime to time. I always check for power after turning off a breaker.
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