Outdoor hot tub on a deck. It is a replacement tub, I was asked to wire it in. The original wiring has a "bond" wire from the pump frame to a ground rod under the deck. The panel box is located on other end of house. There is a continuous ground to the main panel and a 2 pole GFCI breaker. (Is this in the NEC ? ) I am not sure I should rewire the new one to it again. Thanks for any info.
In the 70s and 80s a lot of folks did not understand grounding. Many inspectors required them to and many electricians would install ground rods at all outdoor thingies (pools, hot tubs, light poles). We know better now, but you will still see it happening. Ignore it. Drive it out of sight. Just make sure you have a low impedance path back to the OC device, and all that should be bonded is.
Re: Ground Rod for hot tub??#34499 02/14/0412:07 AM02/14/0412:07 AM
As Earl has mentioned, there is bonding and grounding required for pools and hottubs, and it seems that a lot of people have trouble understanding the difference between bonding the hottub and grounding it.
Re: Ground Rod for hot tub??#34500 02/14/0408:06 AM02/14/0408:06 AM
I know that you don't need a ground rod in order to properly bond a piece of equipment to the building electrical system, that 'grounding' a piece of equipment without bonding it to the OCPD panel is both wrong and dangerous, and that once you have bonded back to the panel, you will have also 'grounded' the electrical equipment.
However, is there any reason _not_ to use this extra ground rod that happens to already be buried in the ground at the location? If this hot tub were in a separate out-building with a subpanel, I presume that the subpanel would _require_ grounding electrodes, connected to the equipment grounding conductor, but isolated from the neutral.
[This message has been edited by winnie (edited 02-14-2004).]
Re: Ground Rod for hot tub??#34501 02/14/0408:55 AM02/14/0408:55 AM
Hi Active as this ground rod is considered a supplementary ground rod many of the regular requirements do not apply.
250.54 Supplementary Grounding Electrodes. Supplementary grounding electrodes shall be permitted to be connected to the equipment grounding conductors specified in 250.118 and shall not be required to comply with the electrode bonding requirements of 250.50 or 250.53(C) or the resistance requirements of 250.56, but the earth shall not be used as the sole equipment grounding conductor.
In short if you choose to install this supplementary electrode you simply connect it to the EGC wherever you want with whatever size wire you want.
Unless there is local amendment I do not see how your inspectors could fail this.
Bob Badger Construction & Maintenance Electrician Massachusetts
Re: Ground Rod for hot tub??#34504 02/14/0412:46 PM02/14/0412:46 PM
The use of the words "supplemental" and "supplementary" might throw some off. A supplemental electrode is one that's required by 250.53(D)(2) to augment an underground metallic water line at a service. A required supplemental electrode still doesn't have to be connected with a conductor larger than a #6 See250.53(E).
A supplementary electrode is, as iwire says, just that. 250.54, and is permitted
Re: Ground Rod for hot tub??#34505 02/14/0409:35 PM02/14/0409:35 PM