Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Electrical

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread Display Modes
Old 01-16-2013, 08:05 AM   #1
Newbie
 
Join Date: Jan 2013
Posts: 2
Share |
Default

Max load on a standard outlet.


I am trying to figure out the best way to charge 20 tablets daily. I use them for a class I teach and will need to charge them every night after class. A transit case will hold 20 tablets and I would like to develop a system so I can charge them while they are stored in the case. I am trying to figure out what is the maximum number of tablets I can plug into a single wall outlet. Each tablet charger has an output of 12V/1.5A. Does anyone have any guidance. Thanks in advance for your help.

pstowe is offline   Reply With Quote
Old 01-16-2013, 08:24 AM   #2
A "Handy Husband"
 
rjniles's Avatar
 
Join Date: Feb 2007
Location: South Carolina Low Country
Posts: 3,936
Default

Max load on a standard outlet.


1.5 amps at 12 volts is approx. 0.15 amps at 120 volts. Call it 0.2 amps to account for transfomer losses. 20 tablets at 0.2 amps is 4.0 amps. One 15 amp circuit is plenty.

__________________
Location:
Coastal South Carolina
rjniles is online now   Reply With Quote
Old 01-16-2013, 08:30 AM   #3
Newbie
 
Join Date: Jan 2013
Posts: 2
Default

Max load on a standard outlet.


So I should be able to daisy chain power strips, then plug them all into one outlet? I know that isn't quite OSHA standard, but would it work? If you're around Charleston, hope you're enjoying the warm weather. That's where I am from. Thanks for the help.
pstowe is offline   Reply With Quote
Old 01-16-2013, 08:39 AM   #4
Member
 
Join Date: Jan 2009
Location: WV
Posts: 2,866
Default

Max load on a standard outlet.


12 volts at 1.5 amps is a power output of 18 watts. I have no idea what the efficiency of the chargers might be, but even if it was as low as 50%, each one would only draw about 0.3 amps at 120 VAC. So plugging in all 20 would only draw around 6 amps. Since wall receptacles are at least on a 15-amp circuit, you could certainly charge all 20 tablets at the same time (assuming there's not a lot of other loads on the circuit).
md2lgyk is offline   Reply With Quote
Old 01-16-2013, 09:13 AM   #5
A "Handy Husband"
 
rjniles's Avatar
 
Join Date: Feb 2007
Location: South Carolina Low Country
Posts: 3,936
Default

Max load on a standard outlet.


2 of these would work



http://www.amazon.com/Tripp-Lite-PS3.../dp/B00005115S

Half way between Myrtle Beach and Charleston. Supposed to be mid 70's today.
__________________
Location:
Coastal South Carolina
rjniles is online now   Reply With Quote
Old 01-16-2013, 10:01 AM   #6
Licensed Electrical Cont.
 
Speedy Petey's Avatar
 
Join Date: Feb 2004
Location: NY State
Posts: 6,779
Default

Max load on a standard outlet.


School safety inspectors HATE plug strips, even thought they are mostly all self protected.
Circuit wise you can do pretty much whatever you want.
__________________
Sometimes I feel like if I answer any more questions it is like someone trying to climb over a fence to jump off a bridge and me giving them a boost.
Answers based on the 2008 & 2011 NEC. If you're on the '14 already I feel sorry for you.
Speedy Petey is online now   Reply With Quote
Old 01-16-2013, 11:33 AM   #7
Special User
 
Join Date: Jul 2012
Location: Idaho, US
Posts: 551
Default

Max load on a standard outlet.


You don't want to plug plug strips into plug strips. Each plug strip should plug directly into a wall receptacle. There is resistance in each plug connection. Plugging strips into strips increases the resistance, which causes heating of the connections.

But as long as each plug strip is plugged directly into a wall receptacle, you could hang 30 tablets off one 15A circuit no problem.
__________________
The above post is for entertainment purposes only. Its contents may, and probably will, lead to legal liability and damage or loss of property, life, or limb. Use at your own risk.
tylernt is offline   Reply With Quote
Old 01-16-2013, 12:22 PM   #8
Semi-Pro Electro-Geek
 
Join Date: Jul 2009
Location: Arizona, USA
Posts: 2,531
Default

Max load on a standard outlet.


Quote:
Originally Posted by tylernt View Post
You don't want to plug plug strips into plug strips. Each plug strip should plug directly into a wall receptacle. There is resistance in each plug connection. Plugging strips into strips increases the resistance, which causes heating of the connections.

But as long as each plug strip is plugged directly into a wall receptacle, you could hang 30 tablets off one 15A circuit no problem.
As long as the total current draw is less than the power strip rating, there's no conceivable way that daisy chaining power strips could cause a problem. The total current draw for all the tablets is so low that it's a non-issue.
__________________
I am a lawyer, but not your lawyer. And who cares anyways? We're here to talk construction. This is DIY advice, not legal advice.
mpoulton is online now   Reply With Quote
Old 01-16-2013, 12:24 PM   #9
Special User
 
Join Date: Jul 2012
Location: Idaho, US
Posts: 551
Default

Max load on a standard outlet.


Quote:
Originally Posted by mpoulton View Post
As long as the total current draw is less than the power strip rating, there's no conceivable way that daisy chaining power strips could cause a problem. The total current draw for all the tablets is so low that it's a non-issue.
My workplace has strict rules against daisy-chaining plug strips, using the above reasoning. Maybe they're being overly cautious, but even so, to avoid disciplinary action, I don't do it.
__________________
The above post is for entertainment purposes only. Its contents may, and probably will, lead to legal liability and damage or loss of property, life, or limb. Use at your own risk.
tylernt is offline   Reply With Quote
Old 01-16-2013, 01:25 PM   #10
Member
 
Join Date: Apr 2011
Location: North Carolina, USA
Posts: 2,431
Default

Max load on a standard outlet.


Quote:
Originally Posted by tylernt View Post
You don't want to plug plug strips into plug strips. Each plug strip should plug directly into a wall receptacle. There is resistance in each plug connection. Plugging strips into strips increases the resistance, which causes heating of the connections.
Bah, negligible. If this were an issue, you'd never sleep at night worrying about all the wire nut connections hidden in your house. Not to mention all the connections in the main panel, electronics and appliances, etc.
jeffnc is offline   Reply With Quote
Old 01-16-2013, 01:30 PM   #11
Special User
 
Join Date: Jul 2012
Location: Idaho, US
Posts: 551
Default

Max load on a standard outlet.


Quote:
Originally Posted by jeffnc View Post
Bah, negligible. If this were an issue, you'd never sleep at night worrying about all the wire nut connections hidden in your house. Not to mention all the connections in the main panel, electronics and appliances, etc.
Connections torqued into intimate contact with wire nuts or clamps have a lot less resistance than the little leaf springs in receptacles just kissing the plug blades...

Anyway, as I mentioned, it's an issue for my employer. Maybe it's an OSHA thing, who knows. I may or may not have daisy-chained plug strips in my house.
__________________
The above post is for entertainment purposes only. Its contents may, and probably will, lead to legal liability and damage or loss of property, life, or limb. Use at your own risk.
tylernt is offline   Reply With Quote
Old 01-16-2013, 01:37 PM   #12
Member
 
Join Date: Apr 2011
Location: North Carolina, USA
Posts: 2,431
Default

Max load on a standard outlet.


Quote:
Originally Posted by tylernt View Post
Connections torqued into intimate contact with wire nuts or clamps have a lot less resistance than the little leaf springs in receptacles just kissing the plug blades...

Anyway, as I mentioned, it's an issue for my employer. Maybe it's an OSHA thing, who knows. I may or may not have daisy-chained plug strips in my house.
I understand.
jeffnc is offline   Reply With Quote
Old 01-16-2013, 06:20 PM   #13
Semi-Pro Electro-Geek
 
Join Date: Jul 2009
Location: Arizona, USA
Posts: 2,531
Default

Max load on a standard outlet.


Quote:
Originally Posted by tylernt View Post
Connections torqued into intimate contact with wire nuts or clamps have a lot less resistance than the little leaf springs in receptacles just kissing the plug blades...
So? The load either exceeds the ratings or it doesn't. The power strips don't "know" whether there's a space ehater plugged into them or a dozen more power strips. As long as the total load is less than the rating of the first power strip, it makes no difference. Current is current. OSHA doesn't like chaining power strips, but I have never seen a logical explanation of why it's supposedly a problem.

__________________
I am a lawyer, but not your lawyer. And who cares anyways? We're here to talk construction. This is DIY advice, not legal advice.
mpoulton is online now   Reply With Quote
Reply

Tags
amperage, outlet, voltage


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
How to add another electrical outlet in bedroom? AMG Electrical 33 09-15-2012 09:20 PM
Add An Outdoor Outlet pokey302 Electrical 3 02-21-2011 08:46 AM
Switched Outlet Issue mjm Electrical 11 01-23-2011 07:41 AM
Adding new ceiling light in place of switched outlet XavierG35 Electrical 2 02-13-2008 09:05 PM
Wiring a switch, power from outlet Big Bill Electrical 4 09-15-2007 03:59 PM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.