15 or 20 Amp

Page 3 of 4  


Losing insurance coverage by doing something stupid doesn't strike me as being very practical. Your estimate of a .6v difference could be correct or it could be very far off. You haven't taken a long list of variables into consideration.
BB
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

When it comes to the law, there's very little "practical" about it. It's about image and what you can convince others of. FUD is far more effective than truth.
If you think my 0.6V estimate is off, please provide the variables you mention and how they effect the calculation. I'm always interested in learning new things and I assume others on this group are, too. Spread facts, not FUD.
Brian ( snipped-for-privacy@precidia.com )
------------------------------------------------------------------------------- Leave it to the computer industry to shorten "Year 2000" to "Y2K". It's that sort of thinking that led to the problem in the first place. ------------------------------------------------------------------------------- ( Couldn't verify my signature? Use http://www.precidia.com/precidia.crt )
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Brian White wrote:

Here an illustration of the effectiveness of FUD:
http://www.cs.umd.edu/~mattkat/Farside/farside1.gif
or:
http://www.worth1000.com/emailthis.asp?entry 197
Best regards, Bob
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Is there any difference between copper, silver, aluminum, and steel, as far as conductivity and electrical properties? You seem to think they are all the same.
BB
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Greg wrote:

OH? You put fifty feet of #17 wire on a 12 A motor and then plug it into a house wire that is #14 and 110 feet from the panel. Ok, right, who cares. Oh, you might want to switch that vacuum for a 12 a table saw.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
George E. Cawthon wrote:

In that case, the motor is designed to run at the lower voltage you get from the voltage drop of long cord. (maybe it's a 105V motor)
Bob
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
zxcvbob wrote:

You are probably right. Doesn't do too much good for the other appliances on the circuit tho.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
A vacuum cleaner motor is not a good example if you want to commplain about voltage drop since they are AC/DC "universal" brush motors that will accept a large swing in voltage with speed being the only penalty. The cord length is selected by the manufacturter as part of the listed assembly tho and I doubt you will see a 50 footer.
BTW I am the guy who wanted the 20a so stop beating me up here.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
A 15-amp breaker in a 120-volt circuit supports 1800 watts (15 x 120 1800). If your loads total less than 1800 watts, the 15-amp breaker will be adequate. Get the wattage rating from the nameplate on each piece of equipment that will plug into this circuit and add up the total.
David DeBoer wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Ray wrote:

Unless the loads are continuous (likely in this case); then the ckt is limited to 80% of the max rating. Jim

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

15amp = 14ga copper. 20amp = 12ga copper.
Either will work, I'll suggest 20 amp, it isn't that much more $$, and gives a bit more capacity, which might be handy for things like laser printers in the future.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
David,
When you ask basic electrical questions like this, it indicates you may not have enough knowledge to be "safe" around electricity. Therefore, expect numerous suggestions to "seek professional help".
If the wiring you plan to install from the distribution panel to outlets for your computer and other "stuff" is 14 gauge, then you MUST use a 15 amp breaker for each circuit. (The breaker protects the wire from carrying too much current and possibly overheating). Expect to have no more than about 1800 watts available. That's the reason the suggestion was made to get the wattage from each nameplate on the equipment and total them.
If you use 12 gauge wire (which is bigger) you must use a 20 amp breaker. This will give you about 2400 watts of capacity.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Given the choice of 15A or 20A, your best deal is to go with the 20A circuit. It doesn't cost that much more and there are other subtle benefits that have not been mentioned.
If you load up one 15A circuit with monitor, computer, laser printer, audio amps, and say there is something else unusual on the circuit like a treadmill, your quality of power will suffer. (Excessive voltage drop, lamps may flicker as the laser printer goes through it's various heat-up cycles, etc. Although the 15A breaker might not actually trip, the higher Ampacity of a 20A circuit (increase load carrying ability of the conductors at 20A) is going to give you a better installation and less voltage variation.
Beachcomber
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Actually, you don't. Your breaker must be rated at the minimum component on the circuit. You could use 1ga wire if you wanted, but if you had one 15A outlet or one piece of 14ga wire, then the breaker cannot be rated more than 15A.
Don't forget that outlets have ratings on them, too! If you have a 20A breaker, you need to use 20A outlets.
Note that this only applies to the "permanent" parts of the circuit. What you plug in to those outlets is up to you.
As an aside... Running multiple circuits "ganged" together (where the wires run adjacent) reduces the rating even further since they do not have the full surface area to dissipate heat.
Brian ( snipped-for-privacy@precidia.com )
------------------------------------------------------------------------------- The future is not set. There is no fate but what we make for ourselves. -- JC ------------------------------------------------------------------------------- ( Couldn't verify my signature? Use http://www.precidia.com/precidia.crt )
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Unless you are specifically know that specific receptacle is going to need to be rated 20 amps, you use a 15 amp receptacle.
Just incase you want to look it up: http://www.urlbee.com?358 last question, references the table on page 70-56
hth,

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Go with a 20a/12ga wire, your laser printer won't dip the line as much.

42
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

This is Turtle.
First get all the amp requirements from the back of the equipment and add it up to see. Most of the time a 15 amp breaker would be fine but add all the amperages up to see. Now this is whay your suppose to do.
Now I would run me a 20 circuit to it and have some spare ability for future additions. Now here is the abilitys of each type wire and breaker to use.
15 Amp Breaker = #14-2 with nake Ground , Romex TW type up to 40 feet and not to exceed. 20 Amp Breaker = #12-2 with nake Ground , Romex TW type up to 40 feet and not to exceed.
These requiements are on the safe side and it should be.
Now if your not well versed in the electrical field i might suggest you get a electrician to run the circuit for you.
TURTLE
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Y'all up thar in Looziana ain't got THHN Romex yet? The rest of the country got it in about 85-86.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

This is Turtle.
We are still tring to get a complete copy of the NEC code without somebody getting a kick back on it in the State Government. We have a ex-governor, Treasurer, Insurance Commisioner, and Gambling Commisioner in Federal prison right now and tring to send some more. They had stolen billions but got cought with some chump change of $600,000,000.00 kick back on one casino kick back job. The Governor was stupid enough to take $1/4 mil. down payment in cash while in Los Vagas to cover some fun on the tables. He took it from a Federal Agent. He got 8 years for stealing 4.1 Billion dollars and taking $6 Mil. from Getty oil company on a law suite by his law firm. When Texeco bought out Getty oil company the state forgive Texeco about the kick back. They still have not got the money back yet for it is all in over sea's banks under different names. They did find some in the Bank of France. He was a starched Democrate and staied the course during the trial. Also they got him in a Federal prison about 1 mile from my house to be near family and friends. The Rotary club here ask the Federal prison for Edwards to speak at one of their Rotary club meetings and was turned down. I guess money talks.
TURTLE
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

    HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.