Pelliott321 wrote:
BTW while monkeying around with my mains stuff and making new power cables for all my gear I was checking on loose screws at the breakers. I check this ever so often and am amazed to find the screws on the load conductor able to take a partial turn to get tight. My breakers are the type that snaps in place with a friction clamp on the neutral. I always thought this was great because you can just pull the breaker out and do what you need to do without shutting down the whole house to rearrange circuits or add a circuit. But the other day after making such an adjustment I found one circuit not working. I just had to wiggle and push down the offending breaker and the circuit came alive. I am now feeling that this might not be so great after all. So now I have to shut the house down and take all the breakers out. Clean the neutral rails and clean and tighten all the neutral clamps on the breakers to ensure the best possible connection.
In the commercial sector (although it should apply to residential as well) it is recommended to perform preventive maintenance such as what you are doing for the very reason that connections get loose due to thermal cycling. In some jurisdictions it is required by code. In Washington D.C. it is required every three years. I had a client that rather than shut the building down they had an electrical contractor take thermal images of their switch-gear to identify hot spots. The imaging identified some issues at that point in time. Just that point in time. About two weeks after the thermal imaging one of the switch-boards went out creating a fire event to the tune of $250,000. They can't say I didn't warn them.