On Monday, December 17, 2018 at 1:00:00 AM UTC-5, wrote:
On Sun, 16 Dec 2018 15:33:13 -0600, Dean Hoffman
wrote:

On 12/16/18 3:16 PM, trader_4 wrote:

I'm using 10 gauge wire. Purchased 20 feet 4 x 10 gauge. Hot, hot, neutral
and ground. $1.96 per foot to be installed into 1/2" PVC conduit as the main
part of the run is outdoors. Metal Clad can be used outdoor only if protected.
PVC can be used indoors, outdoors and underground.

I thought I was missing something there. On another thing that got no response,
did you see where he said he bought the wire already and it's 3 conductors?
He said he's doing the WH and a 20A receptacle. I don't see how you can do
that to code. The problem is with 3 conductors, it's an Edison circuit.
So, it has to have a double pole breaker. If he uses a 20A double pole,
then he's not code compliant with the WH, though we agree that it's so close
to being legal, that it wouldn't bother us. If he uses a 25A double pole,
then he's Kosher with the WH, but then he has a single 20A receptacle on a
25A circuit, which isn't allowed either. Hope he can take that wire back
and get 4 conductor, unless I'm missing something. Funny how these simple
things can get complicated.

Four conductors.
Quote: Purchased 20 feet 4 x 10 gauge Hot, hot, neutral and ground.

What is he going to connect the 4th wire to?
This is a 120v water heater.
A hot, a neutral and a ground.

I guess you didn't read his post or the couple where I commented on it.
He said he was installing one 20A receptacle too. That lead to the problems
with breaker sizing an Edison circuit to support both. And now that I think
about it, maybe there is a more fundamental problem? Can you use an Edison
circuit to support both a hard wired load like a water heater and a
receptacle? I've only seen them used for receptacles.