Using extension cord for computer setup. Safe? Unsafe?

[Helgrimm]

Hello all, so my apartment doesn't have grounded outlets in the bedroom (where my computer setup is), so I am currently running a heavy duty 14 gauge extension cord, (100ft) along the walls to the room. It powers a batter backup unit w two monitors and computer attached to it. I've heard that using extension cords like this could be unsafe. Is it unsafe in this situation? Any electricians have some thoughts here?

[Deleted]

Should be safe if you

• don't exceed its power rating
• don't have pets/kids nibbling at it
• don't roll parts of it into a ball/coil
• don't overstress it mechanically

[Helgrimm]

Should be safe if you

• don't exceed its power rating
• don't have pets/kids nibbling at it
• don't roll parts of it into a ball/coil
• don't overstress it mechanically

Now that you mention it, I do have the excess length in a coil... is that because of heat buildup?

[EyelessCrow]

As long as it has a ground and is heavy duty and rated for whatever power you have going through it I don't see an issue. It's when you start using ungrounded extension cords and daisy chaining power strips that is...uh..special...and I've seen it.

[Helgrimm]

As long as it has a ground and is heavy duty and rated for whatever power you have going through it I don't see an issue. It's when you start using ungrounded extension cords and daisy chaining power strips that is...uh..special...and I've seen it.

When I was setting it up, I almost put it into the same outlet the AC is plugged into; that would've been a dumb move.

[EyelessCrow]

When I was setting it up, I almost put it into the same outlet the AC is plugged into; that would've been a dumb move.

Things like that and space heaters...which in this heat...yeah. Though my coworker right next to me has a hoodie, coat, and beanie on because the AC is "freezing".

[Deleted]

I would plug it into an otherwise low load spur or simply have a sparky wire it into a spare rcd on your consumer unit.14/2awg wiring will see negligble voltage drop over 100ft, about 5%ish, and ncreasing current by the same amount. This is presuming a 1kw load at 110v (9A becoming 9.5A ish). The wire is rated to 15A max, or 1650w at 110v.

It'll be fine for a pc and two monitors but don't plug heater/air con, vacuum cleaner into it

[Kokolums]

Now that you mention it, I do have the excess length in a coil... is that because of heat buildup?

Well, when you take a wire, coil it up, and run an electric current thru it, you create an electromagnet. That's basically how you make a motor.

I have heard of a case where a university coiled up a ton of data wire in the computer maintenance room that fed data to the entire school. It created an electromagnet and actually prevented data from getting through. You're just doing it with electrical wire but it can have...strange effects.

Here's instructions on how to build a motor:

https://www.wired.com/2016/01/how-to...-already-have/

[Deleted]

Now that you mention it, I do have the excess length in a coil... is that because of heat buildup?

Yes. Proper heat dispersion is assumed when calculating the ratings for those cables.
2 or 3 loops is not an issue but when a significant amount of cable is crammed into a small space handling currents at its limits, it may heat up and melt the insulation, causing a short and potentially a fire.



Not sure if your setup draws enough power to cause this though, but better check if your coil can radiate heat well enough and doesn't heat up under full load.

[Linkedblade]

Hello all, so my apartment doesn't have grounded outlets in the bedroom (where my computer setup is), so I am currently running a heavy duty 14 gauge extension cord, (100ft) along the walls to the room. It powers a batter backup unit w two monitors and computer attached to it. I've heard that using extension cords like this could be unsafe. Is it unsafe in this situation? Any electricians have some thoughts here?

Yeah, you should probably get an electrician to replace the socket to something a bit more modern and safer. It's not unsafe, but if you are pulling a lot through it, it can get quite hot. Definitely wouldn't suggest overclocking or anything crazy. The battery backup and the pc on the same line is sketchy. If anything, at least add a surge protector in line rather than a regular splitter.

[Lathais]

Yeah, you should probably get an electrician to replace the socket to something a bit more modern and safer. It's not unsafe, but if you are pulling a lot through it, it can get quite hot. Definitely wouldn't suggest overclocking or anything crazy. The battery backup and the pc on the same line is sketchy. If anything, at least add a surge protector in line rather than a regular splitter.

What? Why would you put the battery backup on a differnt line, then it would not be providing battery backup to the PCs. Also, the batter backup is 100x better than a surge protector. Most surge protectors are really worthless and don't do much anyway. The battery backup acts not only as a real surge protector, because it will absord any surges and not pass them through, but it also protects against brown outs. Instead of just surge protection, it basically offers conditioned power so your PC and everything else plugged into it get exactly the sme amount of power, always no matter what. No variations, which can sometimes occur, especially in houses with poor wiring.

[westom]

Now that you mention it, I do have the excess length in a coil... is that because of heat buildup?

I am still waiting for one reason why a missing safety ground is such a concern? It does nothing to protect hardware.

Also bogus is the fear of heat. If the many were first doing numbers, then heat was never a threat. The threat is other human safety issues that also define why a power cord is only temporary power (ie less than 30 days). Even worse is one recommendation that would put a near zero protector in line.

That safety ground is for protecting human life. Simpler is to install a GFCI. Then three prong appliances still do not have a ground - but human life is no longer at risk.

[Helgrimm]

I am still waiting for one reason why a missing safety ground is such a concern? It does nothing to protect hardware.

Also bogus is the fear of heat. If the many were first doing numbers, then heat was never a threat. The threat is other human safety issues that also define why a power cord is only temporary power (ie less than 30 days). Even worse is one recommendation that would put a near zero protector in line.

That safety ground is for protecting human life. Simpler is to install a GFCI. Then three prong appliances still do not have a ground - but human life is no longer at risk.

What are the other human safety hazards? Tripping hazard? Just wondering why extension cords are supposed to be for temporary use, beyond the liability issues of fools using them improperly (ex. too high electricity load)

[westom]

Just wondering why extension cords are supposed to be for temporary use, beyond the liability issues of fools using them improperly (ex. too high electricity load)

That plug with three prongs defines how much current a cord must conduct safely. A system must not consume any more than that - if on the power cord or if connected directly to a wall receptacle.

Furthermore, a power strip powered by that power cord must have a circuit breaker to also limit current. So again, excessive current must not be on that power cord ... as long as each wire sufficiently sized - ie has a UL listing.

Code says a receptacle must exist every 12 feet. So a six foot standard cord on all appliance must be within read of a receptacle. Then few flexible cords move about; create a human safety threat.

Unfortunately, many extension cords were used in bedrooms. So an AFCI was required on bedroom circuits. To detect and prevent a human threat created by extension cords. Not overloading.

Why is a wall receptacle safe? Wire is located 1) where it does not move and 2) where it is protected. If not also protected, then that wire must be armored. That (not excessive load) is the human safety threat.

Power cord is only temporary power.