Displeasure with the whole NEC pool bonding section

[jch]

Split off of this topic for being mostly off topic. JasonLion

Be sure to go to a real electrical supply store and not a Home Depot or Lowes. You will find #8 is less than half the cost per foot from an electrical supply. While I writing I might as well express my whole displeasure with the whole NEC pool bonding section and the requirements it imposes. The Dang NEC code is based on studies done by students at Georgia Tech determining what they could "feel" or measure for potential in and around a pool. So much of it is entirely arbitrary, yet it became 'law' once published in NEC code. A number 12 wire would have been just as effective and much cheaper than a number 8, but now the building inspectors insist it must be #8 because it is in the code. The same goes with bonding of the pool ladder and such. Personally, my pool is vinyl and the metal rim never had to contact earth ground, except for the code requirement. My decking is PVC. If I didn't "bond" my pool metal and pool water, I could go swimming and let someone throw a corded blender in the pool and no harm would come to me because the entire pool would have no earth potential. Now that I'm bonded, I would feel a shock as it travels through the water to the pool ladder where the final bonding point is. Oh well.. rant over, can't fight the NEC code.

 

[JasonLion]

You are wrong on several points.

#12 wire is about the same at low current levels, but lightning strikes can induce large currents and having heavier wire makes a huge difference in that case.

If the pool is built to code the blender will trip the circuit breaker the instant it is submerged. Without bonding that may well not happen.

Something is always grounded in the pool, bonding or not. If nothing else, the pump almost invariably has grounded metal in contact with the water even if you don't have bonding and everything else is plastic. That means that current would flow from the blender even without bonding, and it would be far less likely that a breaker would trip and you would be in significantly more danger.

There is certainly an argument that the government shouldn't regulate things like private pool electrical safety. But given that it is regulated, the code is written the way that it is for some really good reasons. A large number of electrical professionals spend thousands of hours going through the various risks and coming up with ways to build things more safely. A process that is repeated and improved every few years. They don't come up with the perfect system, but there are strong reasons that have been weighed by many people for every point in the code.

 

[JohnT]

Earth potential has absolutely nothing to do with it. Difference in potential is the problem, and anytime you have a partially conductive medium there will be differences in potential and the resulting current flow. The bonding system greatly reduces the potential differences.