Electrical fuse box question and potential triggered work

[Jeremiah O'Neill]

Hi all,

I am going to see a property this week that has fuses in lieu of circuit breakers.  I am planning on replacing the fuse box, but I am wondering what other work this may trigger.  The house was built in 1960, so I am hoping that there is not knob and tube wiring however, there may be.  Another possibility is that the house is wired with 2-wire cable without a ground.  I realize that if either of these are true I will likely need to rewire the entire house. 

The real question is, say the wiring in the house is 3-wire with a ground and which would not need replacing.  Will the fact that I am replacing the fuse box trigger the need to upgrade all the wiring to code (I.e. add arc fault breakers, dedicated 20amp circuits to the kitchen, etc.)

I am in Massachusetts, if that matters.

Thanks.

[Roy N.]

If the house was built before 1962, you likely have 2-wire (no ground).  If built between 1962 and 1965/66 you may have early Romex NMD-3 wiring: each conductor was 12-gauge and the ground was 16-gauge.   Note that this wire came in variation where the inner conductors were encased in lead.  The cloth covering will normally have Pb on it someplace.   The lead encased wiring was designed for use in wet environments like direct burial (... kind of like a forerunner to UF). The lead is normally not an issue unless you disturb or cut the wiring.   One other thing to note is that all the cloth covered Romex wiring from that era was only certified to a temperature of 60C, where as today's NMD-90 is operational to 90C.  The old Romex is not safe to use with fixtures which generate significant heat (ie. pot lights), so be on the lookout for that.

I looked at a house just last week which had been wired with General Electric BradX 12/2 Pb NMD-3 wiring.   

If the house was built in, or after, 1968, there is the possibility it contains aluminum wiring - you can easily identify this by looking in the panel or pulling several outlets/switch out of a box and examining the wire ends.   Looking in the panel is better, just in-case copper was spliced onto the end of the wire run to attach the receptacle {rather than purchasing the more expensive receptacles designed for use with Al wiring.