I am installing a 120v water heater in a 208/120 breaker box. Oddly, there
are no knockouts. Is that common in 208/120v?

I see three options; your advice on their legality would be appreciated.

1) I can cut a hole with a hole saw. Not a pleasant chore, but possible.
2) There is an outlet in a box just below the breaker box, connected to it
by a 1/2" conduit. I could connect my MC cable to the outlet box and run
the wires into the breaker box by the 1/2" conduit. I presume 1/2" conduit
can take two sets of #12 cable.
3) I can run my circuit to the outlet box and attach it to the wires that
feed the outlet. The outlet is only used for a radio and the water heater
is only 13a, so there should be plenty of capacity.

"jack" wrote in message
.. .
I am installing a 120v water heater in a 208/120 breaker box. Oddly, there
are no knockouts. Is that common in 208/120v?

I see three options; your advice on their legality would be appreciated.

1) I can cut a hole with a hole saw. Not a pleasant chore, but possible.
2) There is an outlet in a box just below the breaker box, connected to it
by a 1/2" conduit. I could connect my MC cable to the outlet box and run
the wires into the breaker box by the 1/2" conduit. I presume 1/2"
conduit can take two sets of #12 cable.
3) I can run my circuit to the outlet box and attach it to the wires that
feed the outlet. The outlet is only used for a radio and the water heater
is only 13a, so there should be plenty of capacity.


More than one wire can go through a single knockout.

If your wire will not fit through an existing one, relocate one of the 110v
to create space.

This option is 100% legal. The others I have doubts about.

"Colbyt" wrote in message
...

"jack" wrote in message
.. .
I am installing a 120v water heater in a 208/120 breaker box. Oddly,
there are no knockouts. Is that common in 208/120v?

I see three options; your advice on their legality would be appreciated.

1) I can cut a hole with a hole saw. Not a pleasant chore, but possible.
2) There is an outlet in a box just below the breaker box, connected to
it by a 1/2" conduit. I could connect my MC cable to the outlet box and
run the wires into the breaker box by the 1/2" conduit. I presume 1/2"
conduit can take two sets of #12 cable.
3) I can run my circuit to the outlet box and attach it to the wires that
feed the outlet. The outlet is only used for a radio and the water
heater is only 13a, so there should be plenty of capacity.


More than one wire can go through a single knockout.

If your wire will not fit through an existing one, relocate one of the
110v to create space.

This option is 100% legal. The others I have doubts about.

All the existing holes have conduit connected to them, so they aren't
available. It might be legal, but it isn't possible.

"jack" wrote in message
.. .
I am installing a 120v water heater in a 208/120 breaker box. Oddly, there
are no knockouts. Is that common in 208/120v?

I see three options; your advice on their legality would be appreciated.

1) I can cut a hole with a hole saw. Not a pleasant chore, but possible.
2) There is an outlet in a box just below the breaker box, connected to it
by a 1/2" conduit. I could connect my MC cable to the outlet box and run
the wires into the breaker box by the 1/2" conduit. I presume 1/2"
conduit can take two sets of #12 cable.
3) I can run my circuit to the outlet box and attach it to the wires that
feed the outlet. The outlet is only used for a radio and the water heater
is only 13a, so there should be plenty of capacity.


A 7/8" hole saw cuts you a 1/2" knockout. Drill a few for the future

RBM wrote:
"jack" wrote in message
.. .
I am installing a 120v water heater in a 208/120 breaker box. Oddly, there
are no knockouts. Is that common in 208/120v?

I see three options; your advice on their legality would be appreciated.

1) I can cut a hole with a hole saw. Not a pleasant chore, but possible.
2) There is an outlet in a box just below the breaker box, connected to it
by a 1/2" conduit. I could connect my MC cable to the outlet box and run
the wires into the breaker box by the 1/2" conduit. I presume 1/2"
conduit can take two sets of #12 cable.
3) I can run my circuit to the outlet box and attach it to the wires that
feed the outlet. The outlet is only used for a radio and the water heater
is only 13a, so there should be plenty of capacity.


A 7/8" hole saw cuts you a 1/2" knockout. Drill a few for the future



What the other guy said about a hole punch (Greenlee?). Makes a much
nicer hole, and little or no debris inside, and no warping of the panel.

--
aem sends...

"aemeijers" wrote in message
...
RBM wrote:
"jack" wrote in message
.. .
I am installing a 120v water heater in a 208/120 breaker box. Oddly,
there are no knockouts. Is that common in 208/120v?

I see three options; your advice on their legality would be appreciated.

1) I can cut a hole with a hole saw. Not a pleasant chore, but
possible.
2) There is an outlet in a box just below the breaker box, connected to
it by a 1/2" conduit. I could connect my MC cable to the outlet box and
run the wires into the breaker box by the 1/2" conduit. I presume 1/2"
conduit can take two sets of #12 cable.
3) I can run my circuit to the outlet box and attach it to the wires
that feed the outlet. The outlet is only used for a radio and the water
heater is only 13a, so there should be plenty of capacity.


A 7/8" hole saw cuts you a 1/2" knockout. Drill a few for the future



What the other guy said about a hole punch (Greenlee?). Makes a much nicer
hole, and little or no debris inside, and no warping of the panel.

--
aem sends...

Big difference in price between a 7/8" hole saw and a greenlee punch,
besides, if he has a panel with no KO's in it, it's a commercial panel, it
ain't gonna warp

"jack" wrote in message
.. .


All the existing holes have conduit connected to them, so they aren't
available. It might be legal, but it isn't possible.


I missed that part of the post. Sorry.

The other posters have good suggestions.

I would have to wonder why everything is in conduit. Is the a commercial
building? Or a Condo type project?

Conduit may be a requirement for certain structures and locations.

Are they all in use? Sometimes when I have to cut open a wall to pull a
wire I add some empty conduit sections to the panel box for future use. I
cap both ends to prevent critter entry.

Try a rental center for the proper tool. It sounds expensive.

How did you get the water heater IN the breaker box?


s


"jack" wrote in message
.. .
I am installing a 120v water heater in a 208/120 breaker box. Oddly, there
are no knockouts. Is that common in 208/120v?

I see three options; your advice on their legality would be appreciated.

1) I can cut a hole with a hole saw. Not a pleasant chore, but possible.
2) There is an outlet in a box just below the breaker box, connected to it
by a 1/2" conduit. I could connect my MC cable to the outlet box and run
the wires into the breaker box by the 1/2" conduit. I presume 1/2"
conduit can take two sets of #12 cable.
3) I can run my circuit to the outlet box and attach it to the wires that
feed the outlet. The outlet is only used for a radio and the water heater
is only 13a, so there should be plenty of capacity.

jack wrote:
I am installing a 120v water heater in a 208/120 breaker box. Oddly,
there are no knockouts. Is that common in 208/120v?

I see three options; your advice on their legality would be
appreciated.
1) I can cut a hole with a hole saw. Not a pleasant chore, but
possible.

Why do you say that? A metal-cutting hole-saw should do the job in less than
two minutes.

RBM wrote:

"aemeijers" wrote in message
...
RBM wrote:
"jack" wrote in message
.. .
I am installing a 120v water heater in a 208/120 breaker box. Oddly,
there are no knockouts. Is that common in 208/120v?

I see three options; your advice on their legality would be appreciated.

1) I can cut a hole with a hole saw. Not a pleasant chore, but
possible.
2) There is an outlet in a box just below the breaker box, connected to
it by a 1/2" conduit. I could connect my MC cable to the outlet box and
run the wires into the breaker box by the 1/2" conduit. I presume 1/2"
conduit can take two sets of #12 cable.
3) I can run my circuit to the outlet box and attach it to the wires
that feed the outlet. The outlet is only used for a radio and the water
heater is only 13a, so there should be plenty of capacity.


A 7/8" hole saw cuts you a 1/2" knockout. Drill a few for the future



What the other guy said about a hole punch (Greenlee?). Makes a much nicer
hole, and little or no debris inside, and no warping of the panel.

--
aem sends...

Big difference in price between a 7/8" hole saw and a greenlee punch,
besides, if he has a panel with no KO's in it, it's a commercial panel, it
ain't gonna warp

The much maligned Harbor Freight has a manual KO punch set rather cheap
that would probably do the job. They also have a hydraulic driver
available.

There is also the option of the Greenlee KO sized step bit, which is
what I use for the small number of times I need to make holes in pull
boxes and whatnot.

Pete C. wrote:
....
The much maligned Harbor Freight has a manual KO punch set rather cheap
that would probably do the job. They also have a hydraulic driver
available.

If the box steel isn't harder than the punch...

HF -- ya pays ya money and takes ya chances...

--

wrote:
....
A Greenlee punch is $30 or so if you shop around and it will last a
lifetime. Over the years I have managed to collect several sizes and
they all still work fine.

Agreed...

--

dpb wrote:

Pete C. wrote:
...
The much maligned Harbor Freight has a manual KO punch set rather cheap
that would probably do the job. They also have a hydraulic driver
available.

If the box steel isn't harder than the punch...

HF -- ya pays ya money and takes ya chances...

Yep, which is why having a HF retail store nearby where you can see the
items in person is a huge benefit. There are a number of gems in their
lineup, as well as many more perfectly serviceable for home shop use
items.

wrote:

On Thu, 10 Jul 2008 17:34:34 -0500, dpb wrote:

Pete C. wrote:
...
The much maligned Harbor Freight has a manual KO punch set rather cheap
that would probably do the job. They also have a hydraulic driver
available.

If the box steel isn't harder than the punch...

HF -- ya pays ya money and takes ya chances...

A Greenlee punch is $30 or so if you shop around and it will last a
lifetime. Over the years I have managed to collect several sizes and
they all still work fine.

Yes, but the HF set is half that. They may not last a lifetime in pro
use however.

Pete C. wrote:
....
Yes, but the HF set is half that. They may not last a lifetime in pro
use however.

The question w/ HF is will they last a single use???

IME it's been a crapshoot...some stuff is amazingly good for the price;
some is pure junk. The problem is there's almost no way to tell a priori...

Since there's no local outlet, I've pretty much given them. Doesn't
mean anybody else needs to take the advice, I was simply making a
(mostly) lighthearted aside...

--

Pete C. wrote:
....
Yep, which is why having a HF retail store nearby where you can see the
items in person is a huge benefit. There are a number of gems in their
lineup, as well as many more perfectly serviceable for home shop use
items.

Wish I'd seen this comment before the other...is there an echo here?

--

"Pete C." wrote in message
...
Yep, which is why having a HF retail store nearby where you can see the
items in person is a huge benefit. There are a number of gems in their
lineup, as well as many more perfectly serviceable for home shop use
items.

For the $15 it is sure to make one or two holes.

I retract the rental suggestion. This is the way to go.


Colbyt

"Colbyt" wrote in message
...

"Pete C." wrote in message
...
Yep, which is why having a HF retail store nearby where you can see the
items in person is a huge benefit. There are a number of gems in their
lineup, as well as many more perfectly serviceable for home shop use
items.

For the $15 it is sure to make one or two holes.

I retract the rental suggestion. This is the way to go.


Colbyt


I still don't know why. To use a 1/2" KO greenlee punch, you have to drill a
hole practically that large to fit the bolt through. You may as well use a
7/8" hole saw. Drill once and you're done... and it's cheaper

Last time I needed a romex connector hole, I did it with a Unibit step
drill. It's bigger than 3/4, so I had to buy the $30 bit. Paid for itself
that day.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"HeyBub" wrote in message
m...
jack wrote:
I am installing a 120v water heater in a 208/120 breaker box. Oddly,
there are no knockouts. Is that common in 208/120v?

I see three options; your advice on their legality would be
appreciated.
1) I can cut a hole with a hole saw. Not a pleasant chore, but
possible.

Why do you say that? A metal-cutting hole-saw should do the job in less than
two minutes.