# Is it safe to parallel wall-wart inputs via a single cable?

I have 4 identical devices each with their own low amperage wall wart, and I want to tidy up my power cabling. (They are more like laptop power supplies than wall warts, as they have an AC cable, instead of just a wall plug.)

I'm not any kind of expert on electricity, but I started thinking about power bars, and assume they must connect things in parallel. This made me think I might be able to cut the all the AC leads off the wall warts and join them together, to create one plugin source feed to all 4.

Is this dangerous, or is it as simple as it sounds? They are grounded, so I would be joining the grounds together as well.

• possible duplicate of Using multiple power supplies to increase current – Nick Alexeev Apr 1 '13 at 0:46
• I don't think I'm asking the same thing- I'm joining the AC side, not looking to get more current on the DC side. – Niall Byrne Apr 1 '13 at 0:52
• It is as simple as it sounds, but why would you exchange a electrically and mechanically safe construction into an unsafe one? Screws tend to loosen over time, thing get stuck, kids or pets get extra curious about what they found ... – jippie Apr 1 '13 at 11:08

Electrically, combining the four AC input cables into one would be equivalent to plugging them all into a common power bar.

However, safely making such a connection would be difficult. Personally, I would prefer to keep the separate plugs, even if I had to buy another power bar (and I do have the skills and tools to make the suggested connection safely).

• I had my reservations about this too, and have actually decided to go with a power bar- but thanks for your insight, and confirmation about how a power bar works. – Niall Byrne Apr 1 '13 at 21:16

If the cable length is the issue, depending on which cable it uses, you might be able to get shorter ones, standard or custom made. For example:

1ft "Figure Eight" C7 cable
http://www.amazon.com/Ziotek-Notebook-Power-Cord-Figure-eight/dp/B000BSLS0W

1ft C13 PC power cable
http://www.monoprice.com/products/subdepartment.asp?c_id=102&cp_id=10228&cs_id=1022801

Or a Y cable of the same? http://www.hosatech.com/product/340384/YIE-406/_/Power_Y_Cable,_Dual_IEC_C13_to_NEMA_5-15P,_1.5_ft

There are even 3 way versions of that cable. And the Mickey Mouse C-5 Cable as well.

A lot of switching power-adapters rely on the AC cable to sufficiently attenuate what would be "illegal" levels of conducted EMC emissions. OK so you were planning on using 4 and this makes a mockery of the governing legislation!!! Who doesn't use a stack of them all connected to a single outlet?

Is it safe? Safe in terms of electrical shock but, maybe not safe to do so without incurring the wrath of the legislative gurus. They can't blame you for using 4 that have been untampered but maybe they can if you've shortened the cables. Will you be caught? No, of course not!!