Can swimming pools become naturally electrified??!?
July 9, 2017 8:19 PM Subscribe
The rental agreement for a vacation home the family and I are considering in North Carolina's Outer Banks has, buried deep in the legalese, a fairly surprising warning about swimming pools. To wit:
We have heard that occasionally a mild ground current has been experienced in some pools in both Dare and Currituck Counties. This appears to be the result of the Earth's own natural electrical current rather than a pool defect or household current. Locations of certain properties may be affected more than others and the currents tend to be intermittent. We want to advise you that certain devices such as pacemakers and other similar devices may be affected. Please follow all safety instructions.
Wait, what? Really? I get that they're just trying to cover themselves. And I'm not particularly worried that we're all going to die horribly in an electrified swimming pool. But really? Can "the Earth's own natural electrical current" really fry your pool and take out your pacemaker? Is this something specific to the Outer Banks? What in the world are they talking about?
We have heard that occasionally a mild ground current has been experienced in some pools in both Dare and Currituck Counties. This appears to be the result of the Earth's own natural electrical current rather than a pool defect or household current. Locations of certain properties may be affected more than others and the currents tend to be intermittent. We want to advise you that certain devices such as pacemakers and other similar devices may be affected. Please follow all safety instructions.
Wait, what? Really? I get that they're just trying to cover themselves. And I'm not particularly worried that we're all going to die horribly in an electrified swimming pool. But really? Can "the Earth's own natural electrical current" really fry your pool and take out your pacemaker? Is this something specific to the Outer Banks? What in the world are they talking about?
It is a poorly installed or maintained pool that has any noticeable electrical gradient any where in it irregardless of whatever current may be flowing around it (and the Earth's own natural electrical current isn't something I've heard of but I'm only an electrician not a geophysicist) .
posted by Mitheral at 11:29 PM on July 9, 2017 [1 favorite]
posted by Mitheral at 11:29 PM on July 9, 2017 [1 favorite]
I expect this is from the same planet of careful lawyers as my car insurance's refusal to cover damage due to the accidental or intentional discharge of any nuclear weapon. Because the first thing I am going to do after the apocalypse is walk my mutant ass to San Antonio and demand a check from USAA.
posted by ROU_Xenophobe at 4:36 AM on July 10, 2017 [25 favorites]
posted by ROU_Xenophobe at 4:36 AM on July 10, 2017 [25 favorites]
the Earth's own natural electrical current isn't something I've heard of
There can exist a different electrical potential between two "grounds" - drive a ground rod into one part of your yard, and and other into a different part, and use a multi-meter and often you will find that one is some voltage higher than the other. This owes to different compositions, water content, etc, but it does in fact exist*. This is why all grounds in a system should be bonded, so the voltages between grounds are the same.
So, yeah, you could, in theory have a current flow through a pool - chlorinated water is actually a pretty decent conductor - and the pool can act as the bonding for the ground from one end to anther. As to whether there would be enough potential to mess with pacemakers and such.... Dunno. But the EM field from a microwave isn't all that strong either, and those warnings are considered serious.
And all of that is leaving out that someone in your area has fault grounded to the water pipes and it's coming out where your pool is.
* there is about a volt and a half between the ground rod at my antenna, and the one at the house where the service comes in. More after it rains, and less as it dries out.
posted by Pogo_Fuzzybutt at 8:21 AM on July 10, 2017 [1 favorite]
There can exist a different electrical potential between two "grounds" - drive a ground rod into one part of your yard, and and other into a different part, and use a multi-meter and often you will find that one is some voltage higher than the other. This owes to different compositions, water content, etc, but it does in fact exist*. This is why all grounds in a system should be bonded, so the voltages between grounds are the same.
So, yeah, you could, in theory have a current flow through a pool - chlorinated water is actually a pretty decent conductor - and the pool can act as the bonding for the ground from one end to anther. As to whether there would be enough potential to mess with pacemakers and such.... Dunno. But the EM field from a microwave isn't all that strong either, and those warnings are considered serious.
And all of that is leaving out that someone in your area has fault grounded to the water pipes and it's coming out where your pool is.
* there is about a volt and a half between the ground rod at my antenna, and the one at the house where the service comes in. More after it rains, and less as it dries out.
posted by Pogo_Fuzzybutt at 8:21 AM on July 10, 2017 [1 favorite]
This may also be intended to allay fears related to the tragic case of a lifeguard who was killed by faulty pool wiring in Raleigh last year. I can imagine a lot of North Carolinians panic about any electric shock they receive near a pool if they are familiar with that story.
posted by Rock Steady at 8:24 AM on July 10, 2017
posted by Rock Steady at 8:24 AM on July 10, 2017
This thread is closed to new comments.
posted by RobotVoodooPower at 8:31 PM on July 9, 2017