Q. re shielded surge suppressor

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  • Answered

Hi, Shaun,

I just watched your video on the shielded surge suppressor power strip and have a question:

When computers, printers, lamps, etc., are plugged into the strip, does the shielding protection extend along the equipment cords themselves, or will these cords continue to give out the same level of EMFs as they would if plugged into a regular surge protector or outlet?

I'm in the process of reducing EMFs in my home-office space and already have some shielding in place for my monitor and laptop. I've also had a building biologist come out recently to assess my living and work space; but I need to reduce EMFs even more and found your surge suppressor online.

Kind regards,


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Satisfaction mark by R_D 6 years ago

Great replies to my questions! Plenty of data and detailed explanations, which are very helpful. I'm also very happy with the shielded surge suppressor I purchased, along with the shielded cable you included. Thank you, Shaun and the ElectraHealth Team!!--RD

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Shaun A Kranish Principal
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Hi RD,

What we have found is that in most cases, the more shielded cords we use, along with the shielded surge suppressor, the lower the numbers go in electric field measurement.  Installing a shielded cord or surge suppressor does not "extend" to non-shielded cords.  However, it can still greatly reduce electric field measurements, even if you are not able to replace all nearby cords with shielded cords.

So our general recommendation for areas where one spends significant time (work areas, bedrooms, etc) is to replace every cord and surge suppressor possible with our shielded version.  It is always best to verify with measurements as well.  But in the vast majority of cases this reduces the readings and optimizes those areas.

Here's a trick: if you have have a shielded cord next to an unshielded cord, it can help to "attach" the two together with zip ties or tape.  Attaching the shielded cord next to the unshielded cord helps to reduce the fields immensely.

We are working right now on a do-it-yourself kit to retro-shield any cord.  It should be available in the next month.

Have you seen our EHS-Shield shielded power cords?  http://www.ehs-shield.com

We have 14 and 16 gauge extension cords.  We also have 18 gauge power cords with C13 ends on them (the kind commonly used for desktop PCs, desktop Apples, monitors, TVs, some printers and stereos and other electronics).  Simply swap-out your standard unshielded cords with these and your electric field exposure should plummet.

We also use these 18 gauge power cords to rewire lamps.  A qualified professional can change the wire to a lamp and if the lamp is metal-bodied also use the cord to properly ground the lamp at the same time.  This is a must-do in my opinion for lamps.

Let me know if this answers it or if you still need clarification or have any other questions.


Hi, Shaun,

Thank you so much for your very detailed reply.

I'm afraid your rewiring suggestions are a bit beyond my understanding and ability to implement myself; but I might make some inquiries to see if there's a local electrician who could do this.

My laptop and external monitor both have transformers on the power cords, so I'm not sure that these could be swapped out for shielded cords.

What is the difference in purpose/usage of 14-, 16- and 18-gauge cords?



Shaun A Kranish Principal
  • Answered

14 gauge cords are capable of up to 15 amps - what most circuit breakers in homes are rated for.  So things like surge suppressors (power strips) usually use a large 14-gauge 15 amp wire.  16 gauge is a smaller wire - capable of safely carrying less current.  So the higher the gauge (also called AWG) number the smaller the wire.  16 gauge is rated for 13 amps.  18 gauge is rated for 10 amps.

Keep in mind even 10 amps is A LOT of power.  Twenty (20) 60-watt incandescent light bulbs would use 10 amps of power.  Our shielded 18 gauge 10 amp cords are commonly used for computers, monitors, some TVs and stereos, some printers, and to rewire lamps and things with lower current draw.

16 gauge extension cords are the typical everyday extension cord.

14 gauge heavy duty (larger wire size) cords handle up to 15 amps and are used for running multiple devices or power tools - larger things.  They have also been used to rewire appliances and larger devices like that.  This is the size we use in our shielded surge suppressor.  This is the size typically used for big things.