We just bought a cabin. It has a 100 amp service breaker, and a service
panel with 5 20 amp breakers.

I know on appliances, all I have to do to find out the amperage is RTFM, but
for lights and such, how do I calculate just how much wattage I can put on
any breaker circuit?

The lighting is inadequate. I will need more. I have a licensed
electrician friend who will come and wire everything, so it will be done
right and safe. I just need to get an idea how many lights we are talking
about so I can do some shopping. I don't want to max everything out and put
up a ton of lights. I just want to balance them, and not put so many that I
am approaching critical mass.

TIA

Steve

SteveB wrote:
We just bought a cabin. It has a 100 amp service breaker, and a service
panel with 5 20 amp breakers.

I know on appliances, all I have to do to find out the amperage is RTFM, but
for lights and such, how do I calculate just how much wattage I can put on
any breaker circuit?

The lighting is inadequate. I will need more. I have a licensed
electrician friend who will come and wire everything, so it will be done
right and safe. I just need to get an idea how many lights we are talking
about so I can do some shopping. I don't want to max everything out and put
up a ton of lights. I just want to balance them, and not put so many that I
am approaching critical mass.

TIA

Steve



Wattage devided by the voltage (120) is amps. Or
just add up the wattage. 20 amps x 120v = 2400
watts. Lights are easy since the wattage is
written on each bulb.

You don't want to exceed 80% of the capacity of the circuit. If you are
using a 15 amp circuit don't exceed 1200 watts on the circuit
"SteveB" wrote in message
news:j1aKe.84965$4o.53276@fed1read06...
We just bought a cabin. It has a 100 amp service breaker, and a service
panel with 5 20 amp breakers.

I know on appliances, all I have to do to find out the amperage is RTFM,
but for lights and such, how do I calculate just how much wattage I can
put on any breaker circuit?

The lighting is inadequate. I will need more. I have a licensed
electrician friend who will come and wire everything, so it will be done
right and safe. I just need to get an idea how many lights we are talking
about so I can do some shopping. I don't want to max everything out and
put up a ton of lights. I just want to balance them, and not put so many
that I am approaching critical mass.

TIA

Steve

"SteveB" wrote in message
news:j1aKe.84965$4o.53276@fed1read06...
We just bought a cabin. It has a 100 amp service breaker, and a service panel
with 5 20 amp breakers.

I know on appliances, all I have to do to find out the amperage is RTFM, but
for lights and such, how do I calculate just how much wattage I can put on any
breaker circuit?

The lighting is inadequate. I will need more. I have a licensed electrician
friend who will come and wire everything, so it will be done right and safe.
I just need to get an idea how many lights we are talking about so I can do
some shopping. I don't want to max everything out and put up a ton of lights.
I just want to balance them, and not put so many that I am approaching
critical mass.

TIA

Steve

this is Turtle.

In normal lighting circuits it is hard to over load normal lighting wattages to
just light up a cabin. Just take 1 -- 20 amp breaker and circuit for lights only
and that gives you 20 -- 100 watt light bulbs to light up the cabin. One Circuit
is what I thinik you need for all lighting to the cabin.

Now really 19.6 -- 100 watt light bulbs to be exact.

TURTLE

"TURTLE" wrote in message
...

"SteveB" wrote in
message news:j1aKe.84965$4o.53276@fed1read06...
We just bought a cabin. It has a 100 amp service
breaker, and a service panel with 5 20 amp breakers.

I know on appliances, all I have to do to find out
the amperage is RTFM, but for lights and such, how
do I calculate just how much wattage I can put on
any breaker circuit?

The lighting is inadequate. I will need more. I
have a licensed electrician friend who will come and
wire everything, so it will be done right and safe.
I just need to get an idea how many lights we are
talking about so I can do some shopping. I don't
want to max everything out and put up a ton of
lights. I just want to balance them, and not put so
many that I am approaching critical mass.

TIA

Steve

this is Turtle.

In normal lighting circuits it is hard to over load
normal lighting wattages to just light up a cabin.
Just take 1 -- 20 amp breaker and circuit for lights
only and that gives you 20 -- 100 watt light bulbs to
light up the cabin. One Circuit is what I thinik you
need for all lighting to the cabin.

Now really 19.6 -- 100 watt light bulbs to be exact.

TURTLE

Not the best idea: Pop the breaker an dthe whole place
goes dark. They should be mixed on at least two
breakers, and instead of 20 bulbs, that would be 16
bulbs. Over 80% usage will allow normal variations in
the grid, cabin, over time, breakers, etc. to begin to
heat the breaker, thus degrading it over time and
leaving no safety overhead. So with a min two lines
you've got 32 bulbs now, lots more than you'll need.
Not sure where the 80% figure comes from, nec, ul, mfg,
whatever, but it's reality.

HTH,
Pop

"Pop" wrote in message
...

"TURTLE" wrote in message
...

"SteveB" wrote in message
news:j1aKe.84965$4o.53276@fed1read06...
We just bought a cabin. It has a 100 amp service breaker, and a service
panel with 5 20 amp breakers.

I know on appliances, all I have to do to find out the amperage is RTFM, but
for lights and such, how do I calculate just how much wattage I can put on
any breaker circuit?

The lighting is inadequate. I will need more. I have a licensed
electrician friend who will come and wire everything, so it will be done
right and safe. I just need to get an idea how many lights we are talking
about so I can do some shopping. I don't want to max everything out and put
up a ton of lights. I just want to balance them, and not put so many that I
am approaching critical mass.

TIA

Steve

this is Turtle.

In normal lighting circuits it is hard to over load normal lighting wattages
to just light up a cabin. Just take 1 -- 20 amp breaker and circuit for
lights only and that gives you 20 -- 100 watt light bulbs to light up the
cabin. One Circuit is what I thinik you need for all lighting to the cabin.

Now really 19.6 -- 100 watt light bulbs to be exact.

TURTLE

Not the best idea: Pop the breaker an dthe whole place goes dark. They should
be mixed on at least two breakers, and instead of 20 bulbs, that would be 16
bulbs. Over 80% usage will allow normal variations in the grid, cabin, over
time, breakers, etc. to begin to heat the breaker, thus degrading it over time
and leaving no safety overhead. So with a min two lines you've got 32 bulbs
now, lots more than you'll need. Not sure where the 80% figure comes from,
nec, ul, mfg, whatever, but it's reality.

HTH,
Pop

This is Turtle.

He was asking what number of breakers would be need for lighting for the cabin.
I said 19.6 for a 20 amp breaker will support the 19.6 light bulbs and will be
the 80% of the amperate of the 20 amp breaker. He can split up the bulb in all
area , but all lighting would not need more than 1 --- 20 amp circuit, no matter
how he run it.

With two circiuts of 20 amps he could put not 32 -- 100 watt light bulbs but
39.2 --- 100 light bulbs. This would still be compliant of the 80% rule of the
two 20 amp breaker circuits.

Now the degrading of the breaker to trip at lower amperages is just a effect you
have to deal with 20 to 30 years from now and just wait 20 years or so and think
about them.

TURTLE

Dear Steve, the formula is

volts times amps = watts

So, you can say that the 110 volt circuit, times 20 amps = 2200 watts.

Hint: Try using flourescent, or compact fluorescent bulbs. They use a lot
less power.

--

Christopher A. Young
Learn more about Jesus
www.lds.org
www.mormons.com


"SteveB" wrote in message
news:j1aKe.84965$4o.53276@fed1read06...
We just bought a cabin. It has a 100 amp service breaker, and a service
panel with 5 20 amp breakers.

I know on appliances, all I have to do to find out the amperage is RTFM, but
for lights and such, how do I calculate just how much wattage I can put on
any breaker circuit?

The lighting is inadequate. I will need more. I have a licensed
electrician friend who will come and wire everything, so it will be done
right and safe. I just need to get an idea how many lights we are talking
about so I can do some shopping. I don't want to max everything out and put
up a ton of lights. I just want to balance them, and not put so many that I
am approaching critical mass.

TIA

Steve

Stormin Mormon wrote:

volts times amps = watts

So, you can say that the 110 volt circuit, times 20 amps = 2200 watts.

Hint: Try using flourescent, or compact fluorescent bulbs. They use a lot
less power.

At a lower power factor... watts = 0.4 x volts x amps,
for some undercounter fluorescents.

Nick

wrote:
Stormin Mormon wrote:


volts times amps = watts

So, you can say that the 110 volt circuit, times 20 amps = 2200 watts.

Hint: Try using flourescent, or compact fluorescent bulbs. They use a lot
less power.


At a lower power factor... watts = 0.4 x volts x amps,
for some undercounter fluorescents.

Nick

Do fluorescent lights have a power factor? would
like to know. But, that said, if the undercounter
light fixture say 15W, then that is how much is
used regardless of power factor and w=va still
applies. or am I wrong and the labels are incorrect.

George E. Cawthon wrote:

...watts = 0.4 x volts x amps, for some undercounter fluorescents.

Do fluorescent lights have a power factor?

Sure... 0.4 in the case above.

But, that said, if the undercounter light fixture say 15W, then that
is how much is used regardless of power factor

Yes.

and w=va still applies. or am I wrong...

You am wrong. W = PFxVxA.

Nick

wrote:
George E. Cawthon wrote:


...watts = 0.4 x volts x amps, for some undercounter fluorescents.



Do fluorescent lights have a power factor?


Sure... 0.4 in the case above.


But, that said, if the undercounter light fixture say 15W, then that
is how much is used regardless of power factor


Yes.


and w=va still applies. or am I wrong...


You am wrong. W = PFxVxA.

Nick


Did you go to embassy doublespeak school? If you
did, congratulations in your studies. You
certainly confused me. You answered the 2nd
question yes and the third saying I am wrong.
Those answers are inconsistent. The subject was
totaling up the wattage or amps. If the fixtures
says 15 watts and it has a power factor, the
powerfactor is already applied. If you total it
up with other appliances you don't apply the power
factor again.

I think I'll just stick with totaling up the
wattage of fixtures/appliances.

In article ,
wrote:
George E. Cawthon wrote:

...watts = 0.4 x volts x amps, for some undercounter fluorescents.

Do fluorescent lights have a power factor?

Sure... 0.4 in the case above.

But, that said, if the undercounter light fixture say 15W, then that
is how much is used regardless of power factor

Yes.

and w=va still applies. or am I wrong...

You am wrong. W = PFxVxA.

Nick


QUESTION about this "power factor":

(it has been *so long* since I understood any
of that stuff, that I've forgotten all but a
few words describing it.)

With DC, the pf is 1.0?

With AC, I'm not sure what it is.

Of course there's the "rms" stuff, trying to
get an average value of a sine-wave.

The pf, I recall from *ages* (decades) ago, had something to
do with the voltage and current "waves" getting out of sync
with each other, due to a coil or a capacitor (one shifting
in one direction, one in the other).

I recall something about having to use trig to get
the pf, maybe it was the sine or cosine of the degrees
of lead or lag?

If so, then since those functions range between plus and
minus one, then maybe the pf I dimly recall is the
reciprocal of yours?

Anyway -- here's my question:

How do you get a substantial pf for a fluorscent (sp?)
light? (Huge electric motor, I understand how.)

And a pf for an incandescent light, that would involve
no phase shift at all?

Obvously, I could use some mental fill-in!

Thanks!

David