Expanding Your Outlets on a Surge Protector

A TechLore "Ask the Experts" Question...


If I plug in an extension cord with multiple outlets into my surge protector, will components that I plug into the extension cord still be protected even though they are not directly plugged into the surge protector?

-Submitted by Ron 


The simple answer to your question is yes, devices plugged into a power strip that is plugged into a surge protector will still continue to reap the benefits of the surge protector. It's similar to an in-line volume control for headphones. The headphones would not be directly plugged into the device, but the sound still gets there.

In any form of in-line surge protector, as long as the electricity flowed through it prior to reaching the device, it will maintain the benefits of using it.

However, surge protection in itself is not just about plugging a device into a box. In-series surge protectors have to abide by the inherent properties of electricity. The most important rule for in-series surge protectors is that electricity always follows the path of least resistance. This means that all incoming lines to a system must be connected to the surge protector, which cuts off the system from any other outside source. These incoming lines include cable, satellite, telephone, etc.

If, for example, all of your devices' electrical cords were plugged into a surge protector, but the cable line plugged directly from the wall to the back of your TV, the system is not really protected from power fluctuations. Simply explained, since the cable line bypasses the surge protector, it creates a path of lower resistance to another ground, which is the path that a surge will then take if one occurred. True surge protection means cutting off the system from the outside world, so that the surge protector can balance the resistance to the rest of the system keeping itself as the least resistant path. This way it will be able to dissipate the surge, reroute the surge, or destroy itself.

Connecting a power strip to a surge protector also does not help with EMI and RFI interference. Using this method to add more outlets will increase these forms of interference, which could degrade the performance of your system.

For more information about surge protectors, read the article Protecting Your Home Theater System.

Matt Whitlock - Editor, TechLore.com


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