Home electrical wiring

M

mecdrox

Limp Gawd
Joined
Dec 16, 2002
Messages
187
What sort of wiring would be best to get for my crazy super computer with a 1200 Watt power supply.

A number of years ago the [H] did an article about what sort of wiring is best for the home. I can not locate it now. :/ Do I get a dedicated 20 amp 110 volt outlet?

Any advise you guys could hit me with would be great!

-Mecdrox
 
I would go with dedicated 20 amp MWBC. This will give you 40 amps worth of power. You break the tab off the hot side of the plug, and run 12/3 wire (2 hots 1 neutral 1 ground) so the neutral connects normally, and the hots connect on a separate screw of the plug. It's like having two 20 amp circuits. You'd use a double pole breaker for this and ensure the breaker is seated so each side is on a different leg. Most panels stagger them so it should not matter. Basically if you read 240 volts from both hots (the smaller slot) you're good to go. The 20 amp outlets have a sideways T slot for the neutral but will take a regular plug also.


Keep in mind the 1200w psu is not actually drawing 1200w but if it's a super high end machine, never hurts to be future proof eh.
 
My father and brother are both licensed electricians.

On the other side of my office wall is the garage where the electrical panel is.
My father wired it so that I have 2 dedicated electrical circuits behind my desk each with 15 amps capacity. 2 outlets = 4 plugs.
It was really easy to do and was done right without any weird modifications on my part.
Having 2 separate circuits also cuts out any noise from other electrical devices in the house (e.g. the hair dryer).
In older homes when you turn on a device that uses a lot of wattage you might actually see the lights dim for a moment.

From the attic if you have access they can locate your office wall and drop a chain with the wire on it so the chain will rattle against the wall and they can easily find it and make the connection. From a wall that is up against the garage like mine it's a simple matter of moving things out of the way and running the wires and cutting the holes for the wires and the outlets. You might also have easy access under the house.

An electrician would charge an amount depending on how easy it is to get into the wall behind your desk or the closest wall with the least amount of trouble.
Call one and ask for an estimate.


If you are close to the electrical panel or can wire under the house without too much trouble this is the simplest solution and won't get you killed making modifications you don't understand. You really don't want to be breaking off tabs on something while playing around with a 20 amp circuit while making what you think is a 240 volt connection to "fool" it into a 40 amp that really is not.
 
If you look at his rig specs, he is going to be getting close to that 1200w. those raptors are power hogs @ 10k RPM, plus he oc'd everything. :) Nice rig BTW
 
If you are going to the trouble of installing a dedicated circuit then IMO you may as well make it a 240V circuit, pretty much all PC PSUs can run on 240V and IIRC they usually run slightly more efficiantly at that voltage plus it keeps the current more managable..
 
A 240 volt line running over paper insulation or behind walls without the proper grade of wire can easily cause a fire.
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Twice the voltage means half the current and that means LESS chance of things overheating.

Obviously cable should be suitable for the voltage and current of the circuit being installed but frankly if you can't get that right then you shouldn't be installing electrics at all.
 
"plugwash" Did you read what "Red Squirrel" had to say?
Do it him self directions?
And he is talking 40 amps with 240 volts and breaking a tab on "somthing" to make a connection "to something" so I don't think you know anything at all about it.

I dont't think it had gotten past etting hurt

Did you read the specifics?
They are not really good and can get you dead very quickly

--

Yes up the voltage and run an extension cord directly into the electrical box

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Red Squirrel said:
I would go with dedicated 20 amp MWBC. This will give you 40 amps worth of power. You break the tab off the hot side of the plug, and run 12/3 wire (2 hots 1 neutral 1 ground) so the neutral connects normally, and the hots connect on a separate screw of the plug. It's like having two 20 amp circuits. You'd use a double pole breaker for this and ensure the breaker is seated so each side is on a different leg. Most panels stagger them so it should not matter. Basically if you read 240 volts from both hots (the smaller slot) you're good to go. The 20 amp outlets have a sideways T slot for the neutral but will take a regular plug also.


Keep in mind the 1200w psu is not actually drawing 1200w but if it's a super high end machine, never hurts to be future proof eh.
Click to expand...

What the...???? A 240V line at 20 Amps does not give you 40 Amps. You forgot to tell him to size the wire properly. 20 Amps requires 12 AWG wire. He will also need to replace the PSU cord for one that turns the neutral prong 90 degrees. This is so that you can't plug 110V devices into a 240V receptacle.

plugwash - If you are going to the trouble of installing a dedicated circuit then IMO you may as well make it a 240V circuit, pretty much all PC PSUs can run on 240V and IIRC they usually run slightly more efficiantly at that voltage plus it keeps the current more managable..
Click to expand...

You are correct.
 
Maybe I was not clear.

What you do is you use 12/3 wire, that's 2 hots (usually black and red), a neutral (white) and ground.

You run it from a double pole breaker, the red and black go to the two screws of the breaker (order does not matter). These two carry 240 volts, but that's irrelevant here. The neutral goes to the neutral bus bar as normal.

at the plug, you break the tab for the hot side. That leaves you with 2 screws that are not linked. The red wire goes on one, the black on the other. Neutral goes on the other side. That gives you 2 20 amp circuits, totaling you to 40 amps worth of power in a single outlet. You need to use 12 awg wire for this of course. You can do the same with 15 amp circuits if you want, but may as well use 20. Make sure you use an outlet rated for 20 amps.


wired%20duplex%20receptacle%201%20cr.jpg


The neutral is shared but as long as the hots are on opposite leg (which is a must for this that's why a double pole breaker is used) then it's safe. The neutral only carries the difference in current, not the total.


Oh and if you go with a 240v circuit, please use the proper outlet for it and don't do like the idiots at my workplace did. You might know it's 240v but a future owner may not.

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Yes,

Easily understood

You run the extension cord from your main electrical box to your computer from the garage, leave the door open a litle, then down the hall and then connect it to your computer and them turn it on.



Almost forgot: "break something off"

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Check your PSU. Many power supplies will run at 240v. I think the optimum configuration would be to run an isolated grounded 240v circuit to the power socket that will feed your PSU. Also if possible have a dedicated grounding rod just for that circuit. That should give your psu a very high quality circuit to work with.
 
Also if possible have a dedicated grounding rod just for that circuit.
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DO NOT use multiple seperate grounds in an installation unless you REALLY know what you are doing. Potential differences between different grounds can be a source of both electric shock hazards and of damage to equipment.
 
JSpyder said:
Yes,

Easily understood

You run the extension cord from your main electrical box to your computer from the garage, leave the door open a litle, then down the hall and then connect it to your computer and them turn it on.



Almost forgot: "break something off"

--
Click to expand...

I would not use an extension cord for a permanent situation. In fact they are not allowed in commercial settings so I tend to use the same rules at home. Best to just run an outlet as suggested and plug the PC's UPS/surge bar into said outlet.

And yeah never use multiple separate grounds that are not connected to each other. Typically you have a couple grounding rods, and a ground at a copper pipe, these are all bonded together with the incoming neutral at the main panel.
 
If you have to ask on a forum... better leave it alone... it will work fine. I dont know how its done in America but every room has its own breaker for the outlets here. Also i highly doubt it will draw anywere near 1200w. Wont be a problem even if it does
 
plugwash said:
DO NOT use multiple seperate grounds in an installation unless you REALLY know what you are doing. Potential differences between different grounds can be a source of both electric shock hazards and of damage to equipment.
Click to expand...


Thanks for the warning.

It's not simple to do and does require a well designed system with proper components and proper installation. Properly designed isolated grounded circuit will help eliminate potential differences to protect electrical equipment and provide a clean ground point.

Best bet is to get a qualified electrician to do the work and pull a permit from your local city for an inspection of the work.
 
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Be sure to post if you manage to burn your house down following these instructions....
 
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