More questions about SWG grounding
Thanks for your information. I have more questions though. We talked to the electrician, and he said that our panel, pool equipment and pump is grounded with a rod to the ground. He suggested that we hook a ground rod and wire to the ladder and run it into the ground. He says this will take care of the ladder since it was installed after the pool was built. Do you agree? Thanks, Dorie
Codes, risks and reasonability
Hi Dorie;
As is often the case, sudden changes prompt sudden action. In your case, you are looking at an increase in bleach prices, and have decided to go with an SWG.
Now, I think SWG's are often helpful, and -- unless you get a bad one, or a bad installation -- almost always more convenient than bleach. But, they aren't cheaper, even with bleach at $1.30 per gallon. Several threads, in the SWG are centering on annual operating costs in the $60 - $100 per season range. The (corrected) calculations I've seen seem reasonable. But, even at $1.30 per gallon, not many pools will spend more than $100 per season on bleach. If you did, you probably need to post your chemistry info, so someone can make sure you aren't doing something wrong.
Keep in mind, too, that most SWG users here *still* use bleach for start up, heavy bather loads, and so forth.
When you add in the $500 - $1500 installed cost of an SWG, you aren't looking at any savings, even if you divide the cost of the SWG over 20 years.
This doesn't mean you shouldn't get an SWG; it just means you shouldn't think that doing so will save you money.
On to the codes . . .
I can verify, from much experience, that most electricians don't know how to apply the pool section of the NEC, and even fewer understand WHY those requirements exist or WHAT they accomplish. JohnT's explanation of the difference between bonding and grounding is correct; Mike_in_NJ correctly notes that lack of bonding can lead to more corrosion, but it's also true that bonding itself can increase corrosion, under certain conditions.
And, Mike_in_NJ is also correct that bonding requirements have safety concerns at their core. But, will the lack of a bonded ladder substantially increase your risk of injury by electric shock? The answer is, "Only very rarely, and usually only if something else is wrong."
To put it another way:- I won't let my family swim in an unsanitized pool, and those are very common.
- Until they could swim 400 yards non-stop, I wouldn't let my boys swim, unless an able swimmer (preferably a lifeguard) was scanning the swim area continuously. Sometimes, that meant that my wife or I had to 'be' the lifeguard, at pools where the guards goofed off.
- But, my family does now swim at pools where not all the deck hardware is properly bonded.
Bonding is an excellent idea. But, my judgement is that, in the absence of other serious problems (and it's true, I do have the luxury of usually knowing a lot about the design and construction of the pools where we swim), lack of a bonded ladder doesn't really concern me. It's a risk, of course. But, it's almost certainly not as big a risk as the risk of dying from aflatoxin poisoning my boys face each time they eat peanut butter.
So, what am I saying?- Don't get an SWG because it's going to save you money. Get it, only if the other benefits of an SWG are worthwhile to you.
- Don't bond because of a risk of increased corrosion: there's not much evidence to support that.
- If you are hypervigilant about risks, then you probably should be pay what it costs to get the ladder bonded. But, if you ever allow youngsters to swim without having adult eyes on them every single minute they are in the pool . . . then you are worrying about minor risks, when you should worry about more major ones.
Hope this helps.
Ben
PoolDoc
