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So, is it safe to plug a power bar in to another power bar that is connected to a power source? I don't really want to try it, as if it is unsafe, then I don't want to burn my house down or something.

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  • @GoneBoyGone can you show or describe your many loads?
    – Skaperen
    Jul 21, 2019 at 2:59

4 Answers 4

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Yes but only if the total power drawn is less than the rated capacity of the source and the ratings of the power bars.

So you cannot exceed the power rating of source, bar 1 or bar 2.

I thought this was worth a diagram:

Diagram

I assumed 15A just as an example, respect the ratings and regulations for your locality. I also assumed all bars and source are rated at 15A...

If bar 1 is only rated at 10A then that is the limit so the bottom 3 examples will have to change so that the bar 2 uses less...

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  • OP means "daisy chain" when he says "leapfrog." Jul 20, 2019 at 19:34
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    @PhilFreedenberg I understood that and it is covered by the way I phrased my answer...
    – Solar Mike
    Jul 20, 2019 at 19:35
  • Thanks, just needed this for my Computer, that has way too many connections behind it. I got the power rating on them correct and so far I've had no problems, thanks :) Jul 21, 2019 at 10:02
  • @GoneBoyGone I do the same, need two for sorting tv with amp etc
    – Solar Mike
    Jul 21, 2019 at 10:36
  • The setups suggested as acceptable in this answer violate OSHA regulations, other than the first one.
    – nick012000
    Jul 21, 2019 at 14:07
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It really, really depends on the loads involved (in amps), and you shouldn't be anywhere near the nameplate rating of these power strips, because they are oh, so very cheaply made.

So if you want to plug in a bunch of wall-warts and cell phone chargers and maybe a PC, that is fine. However if you have any sort of high-current (high heat making) appliance like a big gaming PC, laser printer, air conditioner, floor heater, you name it, then you should definitely avoid it unless you are using a very high quality strip like Tripp-Lite. For those appliances, run a quality extension cord straight from the receptacle. (you can't have 2+ of them on a circuit anyway).

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No, it is not. This violates safety regulations.

These devices are only approved to provide power to a specific number of electrical appliances, and daisy chaining them increases that number and creates a potential fire risk. Additionally, you shouldn't daisy chain them with extension cords, either, because that is also a risk.

Here's a document prepared for US Congress by their Office of Compliance explicitly stating this, and here's an IEEE document that discusses daisy chaining extension cords.

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Here is the real scoop. Effectively, when you daisy chain anything that has a fuse included to protect the device, you SHOULD NEVER connect one to another. This goes for protected extension cords as well. The reason for this is complicated and you will read a ton of crap online that will justify and explain why you can do this. The answer simply comes down to the current interrupting capability when they are both in series and the voltage drop involved with respect to the value of each resistor. I did this twice and both times the downstream power stripe was destroyed. I sought the reason why and it comes down to Equivalent resistance, voltage drops and current interrupting capabilities when they are combined. Think Ohms law. DON'T do it unless you want a fire in your home.

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    Uh...then why do fused Christmas light strings permit daisy-chaining? Dec 29, 2020 at 12:34
  • I've daisy chained power strips my entire life, for 30+ years now and never had a single problem. Granted we have 250v power in the UK and voltage drops are not really an issue but as long as you aren't overloading the socket it comes out of it you've really no problems and nothing should be getting destroyed, just buy high quality strips of which there are many to choose from. Dec 9, 2023 at 22:30
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    -1 This answer is full of handwaving and devoid of any actual justification (physics). You know, there's at least 5-10 fuse-like devices in series on the way from the generator in a power plant to any mains-fed device: several reclosers (really big breakers) in substations of the power grid, your main house breaker, branch circuit breaker, and a fuse in the device. That trivially shows that connecting fuses in series is perfectly doable.
    – TooTea
    Mar 8 at 23:11

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