DIYbanter - View Single Post

Dean Hoffman[_12_]

On 1/11/20 4:50 PM, wrote:
On Sat, 11 Jan 2020 13:34:59 -0800 (PST), trader_4
wrote:

On Saturday, January 11, 2020 at 4:18:37 PM UTC-5, Dean Hoffman wrote:
On 1/11/20 3:07 PM, dpb wrote:
On 1/11/2020 2:44 PM, BURNER1 wrote:
WE ARE REMODELING THE KITCHEN AND THE EXISTING WIRE IS NM-B 4/2 . IT
IS 2 FT
TOO SHORT FOR THE NEW DOUBLE OVENSÂ* THhaTE KW RATING IS 240V 8.9kWÂ* OR
208 6.7 kW 40 AMP BREAKER WHAT SIZE WIRE SHOULD i HAVE ?

40A breaker is #8, 50A #6.Â* If rewiring the circuit, I'd suggest going
the larger (#6) for the possible decision down the road to have a 50A
appliance.

Is that only 3 conductor? No equipment ground?

And/or neutral? You can generally install new ovens to an existing
circuit that has a shared neutral and ground, but the poster said 4/2
which implies just two conductors?

It was never legal to have an un insulated neutral unless it was type
SE, a loophole I never understood. NM-b is not legal unless there is
no neutral load at all (no light, no clock/timer). Just the fact that
he says #4 makes me wonder if this is aluminum and if so, there is a
fair chance it is actually type SE. That was pretty common up until
1996 code cycle when the 3 wire thing was tossed on new construction.
Adoption lagged that in most places by up to a decade.

What do you think about the breaker size? An online calculator
put the
load at 37 amps.