I am getting ready to install a 2000W 240V heater that will be supllied
by a 30A subpanel running off the main panel (10/3 w/g).

I have a "1/2 size" dual 15A breaker I pulled out of the main panel a
while ago, but was thinking I will need a full size breaker, so that
the two 120V suppies to the heater will be running off different phases
in the subpanel. The way the 1/2 size breaker feeds off the main panel
is through only one "side", so that both 120V to the heater will be
essentially supplied by the same 120V feed from the main panel, so the
two 120Vs to the heater will be "in phase". If I use a standard size
breaker, then it will bridge the two sides of the subpanel, so it will
supply the heater with two 120V from different phases. Is this a
correct assumption?

thx

wrote in message
ups.com...
I am getting ready to install a 2000W 240V heater that will be supllied
by a 30A subpanel running off the main panel (10/3 w/g).

I have a "1/2 size" dual 15A breaker I pulled out of the main panel a
while ago, but was thinking I will need a full size breaker, so that
the two 120V suppies to the heater will be running off different phases
in the subpanel. The way the 1/2 size breaker feeds off the main panel
is through only one "side", so that both 120V to the heater will be
essentially supplied by the same 120V feed from the main panel, so the
two 120Vs to the heater will be "in phase". If I use a standard size
breaker, then it will bridge the two sides of the subpanel, so it will
supply the heater with two 120V from different phases. Is this a
correct assumption?

thx


this is Turtle.

Yes the above will work but you just broke the NEC code as to having a 240 volt
service breaker being joined together if one trips the other will go with it.
This only depends on how safe you want to be or does being in code matter to
you.

TURTLE

I am not sure what you mean. At the main panel, my 30A breakers are
tied. As I understood it, this IS code. The breakers need to be tied
together. At the subpanel, the two 15A breakers are also TIED, since
they will feed the same device.

Your question is a little unclear to me. My answer would be any 240V
appliance must be fed by the proper size double breaker so that if one leg
trips, they both trip or if you turn off the breaker to replace the plug for
example, you will be turning off both legs.
wrote in message
ups.com...
I am getting ready to install a 2000W 240V heater that will be supllied
by a 30A subpanel running off the main panel (10/3 w/g).

I have a "1/2 size" dual 15A breaker I pulled out of the main panel a
while ago, but was thinking I will need a full size breaker, so that
the two 120V suppies to the heater will be running off different phases
in the subpanel. The way the 1/2 size breaker feeds off the main panel
is through only one "side", so that both 120V to the heater will be
essentially supplied by the same 120V feed from the main panel, so the
two 120Vs to the heater will be "in phase". If I use a standard size
breaker, then it will bridge the two sides of the subpanel, so it will
supply the heater with two 120V from different phases. Is this a
correct assumption?

thx

"TURTLE" wrote in message
...
:
: wrote in message
: ups.com...
: I am getting ready to install a 2000W 240V heater that will be
supllied
: by a 30A subpanel running off the main panel (10/3 w/g).
:
: I have a "1/2 size" dual 15A breaker I pulled out of the main
panel a
: while ago, but was thinking I will need a full size breaker,
so that
: the two 120V suppies to the heater will be running off
different phases
: in the subpanel. The way the 1/2 size breaker feeds off the
main panel
: is through only one "side", so that both 120V to the heater
will be
: essentially supplied by the same 120V feed from the main
panel, so the
: two 120Vs to the heater will be "in phase". If I use a
standard size
: breaker, then it will bridge the two sides of the subpanel,
so it will
: supply the heater with two 120V from different phases. Is
this a
: correct assumption?
:
: thx
:
:
: this is Turtle.
:
: Yes the above will work but you just broke the NEC code as to
having a 240 volt
: service breaker being joined together if one trips the other
will go with it.
: This only depends on how safe you want to be or does being in
code matter to
: you.
:
: TURTLE

HUH? What are you talking about? If it's a split-phase system,
the breakers are required to be ganged. Flip one, they both
flip. Did I fall asleep or something?

Regards,
Pop

"Pop" wrote in message
...

"TURTLE" wrote in message
...
:
: wrote in message
: ups.com...
: I am getting ready to install a 2000W 240V heater that will be
supllied
: by a 30A subpanel running off the main panel (10/3 w/g).
:
: I have a "1/2 size" dual 15A breaker I pulled out of the main
panel a
: while ago, but was thinking I will need a full size breaker,
so that
: the two 120V suppies to the heater will be running off
different phases
: in the subpanel. The way the 1/2 size breaker feeds off the
main panel
: is through only one "side", so that both 120V to the heater
will be
: essentially supplied by the same 120V feed from the main
panel, so the
: two 120Vs to the heater will be "in phase". If I use a
standard size
: breaker, then it will bridge the two sides of the subpanel,
so it will
: supply the heater with two 120V from different phases. Is
this a
: correct assumption?
:
: thx
:
:
: this is Turtle.
:
: Yes the above will work but you just broke the NEC code as to
having a 240 volt
: service breaker being joined together if one trips the other
will go with it.
: This only depends on how safe you want to be or does being in
code matter to
: you.
:
: TURTLE

HUH? What are you talking about? If it's a split-phase system,
the breakers are required to be ganged. Flip one, they both
flip. Did I fall asleep or something?

Regards,
Pop


This is Turtle.

i read it as he was going to use a single breaker and the side off another
double breaker.

Yes you feel a sleep for you did not read into what i read.

TURTLE

wrote in message
ups.com...
I am getting ready to install a 2000W 240V heater that will be supllied
by a 30A subpanel running off the main panel (10/3 w/g).

I have a "1/2 size" dual 15A breaker I pulled out of the main panel a
while ago, but was thinking I will need a full size breaker, so that
the two 120V suppies to the heater will be running off different phases
in the subpanel. The way the 1/2 size breaker feeds off the main panel
is through only one "side", so that both 120V to the heater will be
essentially supplied by the same 120V feed from the main panel, so the
two 120Vs to the heater will be "in phase". If I use a standard size
breaker, then it will bridge the two sides of the subpanel, so it will
supply the heater with two 120V from different phases. Is this a
correct assumption?

A single full size breaker obviously only catches one side. Do you mean
using two full size breakers next to each other? Yes, they will catch both
sides.

When I put my last 240 breaker in, I got a duplex breaker. It has 4 half
size breakers. The top and bottom ones are tied to form a 240 breaker, and
the middle two are joined to form a second 240 breaker. Don't know if you
can do that, but if you are short of space...

wrote in message
ups.com...
I am getting ready to install a 2000W 240V heater that will be supllied
by a 30A subpanel running off the main panel (10/3 w/g).

Off of a 30 amp sub? 2000/240 = 8.33 amps You can run this heater off of a
15 or 20 amp double pole breaker.



I have a "1/2 size" dual 15A breaker I pulled out of the main panel a
while ago, but was thinking I will need a full size breaker, so that
the two 120V suppies to the heater will be running off different phases
in the subpanel.

Partially correct, but you will not find 2 phases in your panel unless you
have a really weird service. You will likely have a split single phase 240
volts, and you'll have to be tapping both sides of the split to get the 240
volts.

The way the 1/2 size breaker feeds off the main panel
is through only one "side", so that both 120V to the heater will be
essentially supplied by the same 120V feed from the main panel, so the
two 120Vs to the heater will be "in phase".

If you are wiring a 240 volt appliance, then you won't want to wire up the
load wires to what would essentially be zero volts.

If I use a standard size
breaker, then it will bridge the two sides of the subpanel, so it will
supply the heater with two 120V from different phases. Is this a
correct assumption?

Semi-correct... First, research the definition of electrical phase. Then
realize that you do not have 2 phases in your panel. You have a single split
phase 240 system with a center-tapped grounded neutral for 115 volt
appliances.



thx