Happy 4th to all that believe in freedom to choose

[Pelliott321]

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.

[DaveR]

That is not a neutral connection, it's the power bus.

[SoundMods]

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.

[SoundMods]

That is not a neutral connection, it's the power bus.

10-4

[Pelliott321]

Ok power buss.
got it

[Pelliott321]

BTW when making up these power cords with braided 10ga conductors I found that after I tighten down as hard as I can the screws on the plugs and IEC socket that after about an hour I can still turn 1/4 turn more.

[DaveR]

Copper is soft, relatively speaking.

[SoundMods]

BTW when making up these power cords with braided 10ga conductors I found that after I tighten down as hard as I can the screws on the plugs and IEC socket that after about an hour I can still turn 1/4 turn more.

When I make power cords with stranded wire I tin the wire first to get a more solid connection. With solid wire I do the same because copper corrodes over time and copper oxide is a dielectric.

Either way I solder the conductors in after tightening the screws. That way the connection is long-term solid both electrically and mechanically

[tomp]

Soldering a stranded wire before inserting and tightening into a connector is not a good idea. Copper is soft but solder is much softer. I have found that tinned stranded wire loosens in the connector more than just the bare wire. When a plain copper wire, either solid or stranded is tightened in a connector, the screw breaks through any surface condition and makes a metal to metal contact. It i a good idea to periodically re-tighten them because of thermal ratcheting.

I worked at a company that made motion picture and TV lighting where we had currents so high we used 500MCM wire. We would never think of soldering a connection as the resistance would be too high. Instead we used a hydraulic crimper to fasten the connectors on to the un-tinned stranded wires. I cut one of those connections apart one time and the lug and wire became a solid piece of copper.

Tom

[tomp]

To put conductivity in numbers, lead has only 7% the conductivity of copper and tin 15%. Neither is as good as a direct copper to copper joint.

Tom