On Wednesday, May 18, 2022 at 2:45:09 PM UTC-5, jimbo wrote:
> _I need to run about 170' of wire for a electric dryer, is 10-3 good or should be 8-3?_
>
> --
> For full context, visit https://www.homeownershub.com/maintenance/gauge-wire-for-distance-3202788-.htm

There's a voltage drop calculator here. I think 3% is still the recommended drop.
<https://www.nooutage.com/vdrop.htm>
You should probably run 4 wires instead of three. You'll be ready if you want
something else later. One is equipment ground. Two are for power. The fourth will
be neutral for whatever timer and such the dryer will have.

On Wednesday, May 18, 2022 at 4:11:16 PM UTC-4, dean...@gmail.com wrote:
> On Wednesday, May 18, 2022 at 2:45:09 PM UTC-5, jimbo wrote:
> > _I need to run about 170' of wire for a electric dryer, is 10-3 good or should be 8-3?_
> >
> > --
> > For full context, visit https://www.homeownershub.com/maintenance/gauge-wire-for-distance-3202788-.htm
> There's a voltage drop calculator here. I think 3% is still the recommended drop.
> <https://www.nooutage.com/vdrop.htm>
> You should probably run 4 wires instead of three. You'll be ready if you want
> something else later. One is equipment ground. Two are for power. The fourth will
> be neutral for whatever timer and such the dryer will have.

The "3" in 10-3 (or the "2" in 14-2) only refers to the electricity-conducting wires, not the ground.

IOW 10-3 with ground is a four wire cable.

I'm not sure you that can even buy 10-3 without ground these days, now that just about
everything requires a neutral and a ground.

Since this sounds like a new installation, it requires a x-3 cable with ground, a 4 prong receptacle
and a 4 prong cord. If it's a retrofit i.e. an extension of an existing 3 wire no ground branch circuit,
then he still needs the 4 prong set-up, but I believe that he can get away with adding a ground at
the junction box where the new wire connects to the old. That ground wire must be no smaller
than 10 AWG and must be connected to:

- the panel the circuit is powered out of, or
- a junction box in another circuit served by that panel which has a #10 or larger
ground wire back to the panel, or
- the Grounding Electrode System i.e. the bare wires from the panel to the ground rods/water pipe.

On 5/18/2022 3:18 PM, Marilyn Manson wrote:
> On Wednesday, May 18, 2022 at 4:11:16 PM UTC-4, dean...@gmail.com wrote:
>> On Wednesday, May 18, 2022 at 2:45:09 PM UTC-5, jimbo wrote:
>>> _I need to run about 170' of wire for a electric dryer, is 10-3 good or should be 8-3?_
>>>
>>> --
>>> For full context, visit https://www.homeownershub.com/maintenance/gauge-wire-for-distance-3202788-.htm
>> There's a voltage drop calculator here. I think 3% is still the recommended drop.

3% branch circuit, 2%feeder, 5% total will provide "reasonable
efficiency of operation" - as you said not required by the NEC

>> <https://www.nooutage.com/vdrop.htm>
>> You should probably run 4 wires instead of three. You'll be ready if you want
>> something else later. One is equipment ground. Two are for power. The fourth will
>> be neutral for whatever timer and such the dryer will have.
>
> The "3" in 10-3 (or the "2" in 14-2) only refers to the electricity-conducting wires, not the ground.
>
> IOW 10-3 with ground is a four wire cable.
>
> I'm not sure you that can even buy 10-3 without ground these days, now that just about
> everything requires a neutral and a ground.
>
> Since this sounds like a new installation, it requires a x-3 cable with ground, a 4 prong receptacle
> and a 4 prong cord. If it's a retrofit i.e. an extension of an existing 3 wire no ground branch circuit,
> then he still needs the 4 prong set-up, but I believe that he can get away with adding a ground at
> the junction box where the new wire connects to the old. That ground wire must be no smaller
> than 10 AWG and must be connected to:
>
> - the panel the circuit is powered out of, or
> - a junction box in another circuit served by that panel which has a #10 or larger
> ground wire back to the panel, or
> - the Grounding Electrode System i.e. the bare wires from the panel to the ground rods/water pipe.
>

Seems tacky, but that is what the book says. Exposed #10 would have to
be protected from damage.

On Thursday, May 19, 2022 at 1:49:12 AM UTC-4, bud-- wrote:
> On 5/18/2022 3:18 PM, Marilyn Manson wrote:
> > On Wednesday, May 18, 2022 at 4:11:16 PM UTC-4, dean...@gmail.com wrote:
> >> On Wednesday, May 18, 2022 at 2:45:09 PM UTC-5, jimbo wrote:
> >>> _I need to run about 170' of wire for a electric dryer, is 10-3 good or should be 8-3?_
> >>>
> >>> --
> >>> For full context, visit https://www.homeownershub.com/maintenance/gauge-wire-for-distance-3202788-.htm
> >> There's a voltage drop calculator here. I think 3% is still the recommended drop.
> 3% branch circuit, 2%feeder, 5% total will provide "reasonable
> efficiency of operation" - as you said not required by the NEC
> >> <https://www.nooutage.com/vdrop.htm>
> >> You should probably run 4 wires instead of three. You'll be ready if you want
> >> something else later. One is equipment ground. Two are for power. The fourth will
> >> be neutral for whatever timer and such the dryer will have.
> >
> > The "3" in 10-3 (or the "2" in 14-2) only refers to the electricity-conducting wires, not the ground.
> >
> > IOW 10-3 with ground is a four wire cable.
> >
> > I'm not sure you that can even buy 10-3 without ground these days, now that just about
> > everything requires a neutral and a ground.
> >
> > Since this sounds like a new installation, it requires a x-3 cable with ground, a 4 prong receptacle
> > and a 4 prong cord. If it's a retrofit i.e. an extension of an existing 3 wire no ground branch circuit,
> > then he still needs the 4 prong set-up, but I believe that he can get away with adding a ground at
> > the junction box where the new wire connects to the old. That ground wire must be no smaller
> > than 10 AWG and must be connected to:
> >
> > - the panel the circuit is powered out of, or
> > - a junction box in another circuit served by that panel which has a #10 or larger
> > ground wire back to the panel, or
> > - the Grounding Electrode System i.e. the bare wires from the panel to the ground rods/water pipe.
> >
> Seems tacky, but that is what the book says. Exposed #10 would have to
> be protected from damage.

What seems tacky? Adding a ground wire to an ungrounded branch circuit has been an accepted
practice for as long as I can recall.

Is it the 2nd and 3rd options that make you queasy?. ;-) Would you prefer a home run from the junction
box?

On Wednesday, May 18, 2022 at 4:11:16 PM UTC-4, dean...@gmail.com wrote:
> On Wednesday, May 18, 2022 at 2:45:09 PM UTC-5, jimbo wrote:
> > _I need to run about 170' of wire for a electric dryer, is 10-3 good or should be 8-3?_
> >
> > --
> > For full context, visit https://www.homeownershub.com/maintenance/gauge-wire-for-distance-3202788-.htm
> There's a voltage drop calculator here. I think 3% is still the recommended drop.
> <https://www.nooutage.com/vdrop.htm>
> You should probably run 4 wires instead of three. You'll be ready if you want
> something else later. One is equipment ground. Two are for power. The fourth will
> be neutral for whatever timer and such the dryer will have.

Four wires is required by code, has been since the 90s. Dryer is typically 30A,
for that length run 10 is definitely out, per your calculator you get just over 3%
drop with 8 gauge, so either 8 or 6.

On 5/19/2022 7:55 AM, Marilyn Manson wrote:
> On Thursday, May 19, 2022 at 1:49:12 AM UTC-4, bud-- wrote:
>> On 5/18/2022 3:18 PM, Marilyn Manson wrote:
>>> On Wednesday, May 18, 2022 at 4:11:16 PM UTC-4, dean...@gmail.com wrote:
>>>> On Wednesday, May 18, 2022 at 2:45:09 PM UTC-5, jimbo wrote:
>>>>> _I need to run about 170' of wire for a electric dryer, is 10-3 good or should be 8-3?_
>>>>>
>>>>> --
>>>>> For full context, visit https://www.homeownershub.com/maintenance/gauge-wire-for-distance-3202788-.htm
>>>> There's a voltage drop calculator here. I think 3% is still the recommended drop.
>> 3% branch circuit, 2%feeder, 5% total will provide "reasonable
>> efficiency of operation" - as you said not required by the NEC
>>>> <https://www.nooutage.com/vdrop.htm>
>>>> You should probably run 4 wires instead of three. You'll be ready if you want
>>>> something else later. One is equipment ground. Two are for power. The fourth will
>>>> be neutral for whatever timer and such the dryer will have.
>>>
>>> The "3" in 10-3 (or the "2" in 14-2) only refers to the electricity-conducting wires, not the ground.
>>>
>>> IOW 10-3 with ground is a four wire cable.
>>>
>>> I'm not sure you that can even buy 10-3 without ground these days, now that just about
>>> everything requires a neutral and a ground.
>>>
>>> Since this sounds like a new installation, it requires a x-3 cable with ground, a 4 prong receptacle
>>> and a 4 prong cord. If it's a retrofit i.e. an extension of an existing 3 wire no ground branch circuit,
>>> then he still needs the 4 prong set-up, but I believe that he can get away with adding a ground at
>>> the junction box where the new wire connects to the old. That ground wire must be no smaller
>>> than 10 AWG and must be connected to:
>>>
>>> - the panel the circuit is powered out of, or
>>> - a junction box in another circuit served by that panel which has a #10 or larger
>>> ground wire back to the panel, or
>>> - the Grounding Electrode System i.e. the bare wires from the panel to the ground rods/water pipe.
>>>
>> Seems tacky, but that is what the book says. Exposed #10 would have to
>> be protected from damage.
>
> What seems tacky? Adding a ground wire to an ungrounded branch circuit has been an accepted
> practice for as long as I can recall.
>
> Is it the 2nd and 3rd options that make you queasy?. ;-) Would you prefer a home run from the junction
> box?
>

Ordinary power wiring is pretty traceable. The separate ground wire can
be difficult or impossible to trace. So you run a #10 ground wire from a
laundry ckt j-box. It is concealed and finally goes into a basement and
is split-bolt connected to the Grounding Electrode Conductor. That
connection is not in a box, and far as I know doesn't need to be
accessible. It can be in the ceiling and covered by sheet rock. If it
goes to the service panel (a 3-wire laundry ckt can't be from a
sub-panel), the panel may be recessed so the wire is concealed in the wall.

It can be as traceable as knob-and-tube wiring.

I have fewer problems with grounding 15/20A receptacles. I am not fond
of the method for extending a circuit. You have a laundry ckt that is
4-wire at the receptacle and 3-wire at the panel.