I picked up a Clearwater hot tub on good ol' Craig's list, and I'm getting current (electric) in the water! No, I didn't get in the water. Here is the set up: 110V two speed motor, a Coates heater, both are hard wired into a metal switch box (pneumatic control) with a GFCI receptacle on it. The box has a 3 wire cord that I plugged into my outdoor GFCI receptacle. I have the motor grounded to a 4' long, 5/8" copper coated grounding rod. When I plug it in, the motor comes on at the slow speed setting, when I reached into the water, I felt an electric shock! Nothing major, a little less, perhaps, than licking a 9 volt battery, but nonetheless extremely alarming! The previous owner said the heater was unable to keep up in winter, and might need a new element. Could that be the source of the short? Is it worth troubleshooting this old unit, or is replacing it the only safe alternative?

Thanks for you help!

Your spa is improperly wired! The ONLY place a grounding rod should be on your electrical system is on the main electrical box where power comes into your home ***. Adding another rod somewhere else creates a risk of electrocution. Most likely, you simply have a bad heater element, and possibly a bad GFCI outlet (or it's wired incorrectly).


***
the use of grounding rods, which when installed correctly, have a bare copper wire attached to them (wire used for bonding is required to be bare copper wire). This wire looks exactly the same as a bonding wire. However, the only place grounding through a grounding rod should be done is at the main electrical panel (that's main panel, not sub panel). The reason a main electrical panel is grounded through a grounding rod is to limit the voltage imposed on the entire electrical system by lightning, unintentional contact with higher-voltage lines, or line surges. Besides the grounding rod, the panel needs to also be grounded back into the electrical providers "grid".

Additionally, grounding through a grounding rod has its limitations. Grounding (earthing) of electrical equipment doesn't provide a low-impedance fault-current path to clear ground faults (translation: "lower" voltages don't travel well, or freely, through the surface of the earth). In fact, according to the NEC, code prohibits the use of the earth (a grounding rod) as the sole return path because it's a poor conductor of current at voltage levels below 600V [250.4(A)(5) and 250.45(B)(4)]. In reality what this could do is potentially electrify the ground around the spa and has the potential of ELECTROCUTING you. If you were to be standing on the ground and touch something that IS properly grounded you could be fatally electrocuted (electricity in the electrified ground travels up through you and out to what your touching, which is properly grounded). There's actually a documented case of this happen at a fish farm in the UK. The little fishies were periodically being electrocuted from an improperly grounded/bonded power line TWO MILES AWAY.

Thanks Dr. Spa,

I appreciate your information on grounding rods. I installed the rod and connected it to the motor's grounding teminal as per instructions from the previous owner. He sent a picture of a green insulated wire attached to the terminal, which is a clamp style, on the motor casing, and said to connect it to a grounding rod near the motor. The 4 strand cable coming out of the motor, going into the switch box, has a ground wire that is tied to the heater ground wire, the GFCI on the switch box (unused) and the gound on the 3 strand cord that plugs into the wall. So, if the motor is not supposed to ground to a grounding rod, to what should I ground it?

I'm debating the merits of spending the $100 on a replacement element (hoping this will correct the short), vs. getting a whole new spa pack. The pneumatic switch seems to have only two settings, motor on low with no heat, and motor on high with heat. Temperature control is via a dial down below on the heater itself. This seems inefficient, with no timer, and no topside temp control. Also, it has no ozonator. Do you have any thoughts on this you would be willing to share with me?

Thanks for your time and input.

Bob

The "grounding terminal" you're talking about is actually a BONDing terminal. Notice how BONDING and GROUNDING are spelled, and even pronounced differently " title="Mr. Green" /> That's because they're different things...though, it's common for laymen, and even a few so called professionals I've seen, to be confused. Here's my complete article (from http://www.rhtubs.com/bonding.htm ) Grounding vs. Bonding While many people mistakenly use the terms interchangeably, BONDING and GROUNDING are two very different things, with very different purposes. Again, bonding and grounding are DIFFERENT. HEY, they're even spelled differently. The very simple explanation of bonding is that it is done to prevent you from being shocked/electrocuted when your left hand touches one metal component, and your right hand touches another metal component. By running a wire (bonding wire) from one metal component to another, stray electricity (from a short for example) will equalize through the wire and one metal component will NOT have a greater voltage in it than another metal component. Grounding on the other hand is to give stray electrical current a place to go, other than through you. To some extent, the two work in conjunction with each other, sort of as backups for each other. BUT THEY ARE SEPERATE and DIFFERENT. So why the confusion? One reason may be due to the use of grounding rods, which when installed correctly, have a bare copper wire attached to them (wire used for bonding is required to be bare copper wire). This wire looks exactly the same as a bonding wire. However, the only place grounding through a grounding rod should be done is at the main electrical panel (that's main panel, not sub panel). The reason a main electrical panel is grounded through a grounding rod is to limit the voltage imposed on the entire electrical system by lightning, unintentional contact with higher-voltage lines, or line surges. Besides the grounding rod, the panel needs to also be grounded back into the electrical providers "grid". Additionally, grounding through a grounding rod has its limitations. Grounding (earthing) of electrical equipment doesn't provide a low-impedance fault-current path to clear ground faults (translation: "lower" voltages don't travel well, or freely, through the surface of the earth). In fact, according to the NEC, code prohibits the use of the earth (a grounding rod) as the sole return path because it's a poor conductor of current at voltage levels below 600V [250.4(A)(5) and 250.45(B)(4)]. In reality what this could do is potentially electrify the ground around the spa and has the potential of ELECTROCUTING you. If you were to be standing on the ground and touch something that IS properly grounded you could be fatally electrocuted (electricity in the electrified ground travels up through you and out to what your touching, which is properly grounded). There's actually a documented case of this happen at a fish farm in the UK. The little fishies were periodically being electrocuted from an improperly grounded/bonded power line TWO MILES AWAY.

That's swell Doc! Thanks for spelling out the difference between BONDing and GOUNDING. You've cleared that up in terms that a layman, and even some so-called professionals can grasp. As you might recall, my question was in regards to what I should connect said terminal too. Note that it's spelled differently, and even sounds different than "What's the difference between a grounding wire and a bonding wire?" " title="Smile" /> Bob