15 vs 20 amp circuits

 I'm renovating my basement and have a pretty fundamental question about the
romex cable I'll be running throughout the space for lights and wall jacks.
I'm having my old Federal Pacific breaker panel (150 amps) replaced with a
new Cutler Hammer 200 amp box. Have hired an electrician to do that work for
me. But I wondered why I'd bother with 15 amp circuits (14-2 romex). Is
there a reason not to simply make all three of the circuits I'll be creating
for the new basement 20 amp circuits, using 12-2 romex? Or is there a
fire/shock hazard caused by using the higher amperage circuit breakers on
those standard circuits.

Also, does on GFI protect the entire circuit on which it is located or do I
need to install more? My basement, like so many, sometimes gets wet when the
outside drains are blocked.

 

Wire costs a bit more, and its a bit harder to work with, but there is no
downside other than that.  I haven't used #14 in years.  It has the added
benefit of reducing voltage drop a little.

Properly installed, GFCIs protect the entire circuit.

 mdb wrote:

Cutlet Hammer isn't my favorite brand, but it's certainly better than
FP. As for 15 Amp circuits, while it theoretically saves you a couple
dollars worth of copper, I wouldn't consider it worthwhile. 15 and 20 A
circuit breakers cost the same as do all the other devices you'll be
using so only the wire would be different.

A GFCI circuit breaker will provide protection for everything connected
to it. A GFCI receptacle will provide protection for everything
connected downstream of it as well as what's plugged into it. A GFCI
circuit breaker costs about 5X the price of a GFCI receptacle while
providing the same protection. Generally it's best to simply insure that
the first device on a given circuit is a GFCI receptacle.

 mdb wrote:

I use 15A for lighting circuits, and the occasional dedicated circuit
where 15 is enough -- the wire is much easier to work with.  I use 20A
for all branch circuits.

One GFCI can protect the whole circuit, or part of the circuit, or just
itself.  Depends how and where you wire it.

Bob

 mdb wrote:

If you need for 20 Amp circuits for higher demand devices or whatever.
There is nothng wrong overdoing anything but economics. Copper price is
very high lately. Anything load on GFI breaker or outlet is all protected.