Power feed

[paul dyar]

It is my understanding that you have to run a 4 wire cable now. Is the old 3 wire not safe? Is the power co. going to change all the old power feeds?

Paul

 

[hr3]

4 wire only after the first switch.. 3 wire is still used from the service head to this switch.. At least that is how I read the code..

 

[joe48]

4 wire only after the first switch.. 3 wire is still used from the service head to this switch.. At least that is how I read the code..

That is correct. Just so happens I had the exact same discussion with the electrical code inspector yesterday. 3 wire entrance cable from pole to meter to service panel/breaker, 4 wire from breaker in main panel to any subfeed panel. A second breaker/switch is not required in subpanel for protection but is recommended for a local disconnect.

 

[rambler]

Old stuff that followed the code the year it was installed is grandfathered in, don't need to change old feeds.

The 4 wire design - done properly! - makes the ground circut much safer & more reliable. We all hope we never actually use that wire, it is only there for safety, but if wired up properly it can really save a building or a life if something bad happens.

The old way of doing 3 wires & a seperate groundrad at each building allows for some electrical differences between the buildings, and this can set up odd backfeeds & eddies along waterpipe, telephone wires, etc.

Both ways work; the 4 wire way works a bit safer.

--->Paul