Bonding questions for new jacuzzi tub

Discussion in 'Electrical Forum discussion & Blog' started by RobertZ, Mar 27, 2012.

  1. RobertZ

    RobertZ New Member

    Messages:
    14
    Location:
    Southern California
    Hey everyone,

    As part of my bath remodel I am installing a new jacuzzi tub and heater and understand that they need to be properly grounded and bonded with a 8 AWG solid copper conductor. Having pulled up the subfloor to plumb the new tub, I noticed a solid copper line running under the floor. As far as I can tell, this copper line is clamped to an outside galvinized pipe running into the ground and into the house and the copper line runs from there through the house over to the main panel. Assuming this is the grounding wire, could I connect the 8 AWG solid copper conductor from the tub motor and heater to the grounding wire and be good?

    P.S. I noticed that I don't have a bonding wire that connects to the pipes around the water heater or anywhere else as far as I can see. Is this something I need to have fixed or does the grounding wire being connected to the galvinized pipe take care of this issue?

    Thanks everyone for the help!
  2. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,555
    Location:
    North Carolina
    You could if you want to but it is not required. The purpose of the 8 bonding conductor is to bring everything in the area of the tub to the same potential.

    There is no requirement to bond around a water heater
  3. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,021
    Location:
    Cave Creek, Arizona
    The only bonding required at the water heater is usually to the gas line if you have one. It IS a prudent thing to bond between the hot and cold lines at the heater. It could extend the life of the water heater.
  4. RobertZ

    RobertZ New Member

    Messages:
    14
    Location:
    Southern California
    Hey guys. Thanks for the help.

    I'm still a bit confused about my first question...

    Am I meeting the requirement of grounding and bonding the tub motor and tub heater if I connect the 8 AWG solid copper conductor to the grounding wire I found under the floor?

    Thanks again!
  5. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,555
    Location:
    North Carolina
    There is a big difference between grounding and bonding.
    Grounding is simply the connection to earth and is done for lightning, power surges, unintentional contact with higher voltage lines, and to keep everything stable under normal conditions.

    Bonding is done to ensure a low impedance path for fault current to follow in order to clear a fault by opening an overcurrent device

    Then we have something called equipotential bonding. This bonding is done to reduce voltage gradients in the area of a body of water such as the tub you mentioned. This bonding is not required to hit the grounding electrode or its conductor so there is no need to land it on the copper conductor you found in the floor unless you just want to do so.
  6. RobertZ

    RobertZ New Member

    Messages:
    14
    Location:
    Southern California
    Hey JW,

    Thanks for the explanation. I guess I'm a little confused by the installation directions provided with my American Standard jacuzzi tub. If you look at the image below, Step 2 says to ensure the heater and pump are GROUNDED and BONDED and that they should be connected to a local bonding point. And FIG 3 shows the 8 bonding conductor from the pump going to ground.

    I just want to make sure I'm doing the connection right.

    Thanks for the help!

    bonding.jpg
  7. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,555
    Location:
    North Carolina
    My dear friend, do just a little thinking of this installation.
    The branch circuit that supplies the pump and heater will have something called an Equipment Grounding Conductor that originates in the panel where the circuit originates. This EGC will connect to the same motor frame that the equipotential bonding conductor connects to.

    As I have said already if it trips your trigger then by all means use a split bolt and connect it to the grounding electrode conductor but this connection will need to be accessible after the job is finished. Understand that this connection is not required to be done by the NEC but if is permissible.
    You will have fulfilled the installation instructions with the equipment grounding conductor with the branch circuits that supply the tub.
  8. RobertZ

    RobertZ New Member

    Messages:
    14
    Location:
    Southern California
    First I would like to say that I do appreciate you taking the time to try and help me out. But let me reassure you that I have been doing a lot of thinking about this installation which is why I posted my questions on this forum.

    I understand what an EGC does and that it connects to the motor and heater. What is throwing me off is the instructions requiring the bonding conductor between the heater and motor to be connected to the electrical panel or an approved local bonding point.

    If you are telling me that I don't have to connect the bonding conductor to the grounding electrode conductor I found in the floor, then were should I connect the bonding conductor from the motor? As I have said already, Fig 3 of the instructions is showing the 8 bonding conductor from the pump going to ground. From what you have wrote, it sounds like you are telling me that I don't need to have the bonding conductor from the motor connect to anything. This is what is confusing me.

    The instructions specifically say that the 8 bonding conductor from the motor needs to connect to the electrical panel or an approved local bonding point. No where does it say that the EGC of the circuit branch serving the motor will satisfy this requirement.
  9. kreemoweet

    kreemoweet Member

    Messages:
    374
    Location:
    Seattle. WA
    Are you not supplying this jacuzzi with a circuit that includes an equipment grounding conducter? Is that EGC not connected to the
    motor frame in the wiring compartment where the cord w/plug terminates? If so, then the motor frame (and therefore your 8AWG bonding
    conductor) is already connected to the system grounding means in the service panel, and you need no further connections. Why do you
    think you need something additional?
  10. RobertZ

    RobertZ New Member

    Messages:
    14
    Location:
    Southern California
    Hey Kreem,

    The way I read the installation instructions (previous post #6), the motor frame "shall" have a 8 bonding conductor connected from the frame bonding lug to the home electrical panel or an approved local bonding point. "Shall" meaning that it is required. It does not say anywhere that this is an alternative if you don't have an EGC in your circuit branch. Also, looking at the instructions you can see that in Fig 2 they are showing an EGC in the GFCI and in Fig 3 they are showing the bonding conductor from the motor going to ground. No where in the instructions does it say it should be one or the other so one would have to assume that you need both for a proper installation.

    I'm sorry if I'm sounding dense but I just want to be sure to install this tub the way the manufacturer specifies. If everyone is telling me that there is no bonding conductor required to connect from the motor to ground or another bonding point, are we saying the installation instructions provided by American Standard are written incorrectly?
  11. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,555
    Location:
    North Carolina
    You repeatly make reference to something that in my 40 plus years of electrical trade I have never heard of. What is a “bonding point�

    As has been pointed out SEVERAL times the purpose of the #8 is not to connect anything to earth but INSTEAD to make everything in and around the WATER at the same potential.

    Also as has been pointed out SEVERAL times the NEC does not require this connection BUT if you or American Standard want to make this connection by all means make the connection.

    Also you first statement made in the post above is false. If you did understand then this thread would never have transpired.
  12. RobertZ

    RobertZ New Member

    Messages:
    14
    Location:
    Southern California
    I posted on this electrical forum hoping to find the same kind of great advice I'd found in all of the plumbing forums on this site. Unfortunately this time it wasn't the case.

    J dub, excuse me if my electrical knowledge is no where near your caliber. But then again, that's why I'm here isn't it? I do in fact understand the purpose of an EGC, thanks. But when installation instructions from a well known manufacturer like American Standard call for something I've never heard of, I look for insight from the pros. I guess in this case not even the pro knows what American Standard is asking for.

    My issue with your responses to my questions is that you kept answering and taking shots at me as if I was the one making up these requirements of a bonding point that you never heard in your "40 plus years". Dude, all I was doing was quoting from the installation instructions verbatim. Have you ever heard of the expression "don't kill the messenger"? If the installation requirements I was talking about didn't make sense then why not say that the instructions provided by American Standard are wrong instead of taking shots at me?

    The link to the installation instructions is below. Download it and take a gander at page 13. There you will see the reference to a "bonding point" in all its glory.

    http://m.americanstandard-us.com/assets/documents/amstd/install/Install_1742.pdf.

    So after days of posting and sarcastic responses, all I can say is thanks... for nothin. No worries J dub, I won't be coming back on this forum wasting your time and asking for clarification on the installation requirements of well known companies. And a little word of advice, just because you haven't heard of something in your 40 plus years doesnt mean it doesnt exist. I'm pretty sure I'm not the first guy to install an american standard tub with the same instructions so someone else has come across the term "bonding point".

    Adios

    FYI: In two previous threads asking about installing a tub with motor and heater you instructed them to connect the 8 bonding condutor from the motor to something metal in the area like a copper water pipe. No where in this thread during your sarcastic responses did you ever suggest I do that for my installation.

    http://www.terrylove.com/forums/sho...Heater-Bonding-Panel-to-Electric-Water-Heater
    http://www.terrylove.com/forums/showthread.php?15935-whirlpool-tub-motor-grounding

    Thanks again for the help...
    Last edited: Mar 31, 2012
  13. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,555
    Location:
    North Carolina
    Well you may be better served by reading what the NEC requirement has to say;

    680.74 Bonding.
    All metal piping systems and all grounded metal parts in contact with the circulating water shall be bonded together using a solid copper bonding jumper, insulated, covered, or bare, not smaller than 8 AWG. The bonding jumper shall be connected to the terminal on the circulating pump motor that is intended for this purpose. The bonding jumper shall not be required to be connected to a double insulated circulating pump motor. The 8 AWG or larger solid copper bonding jumper shall be required for equipotential bonding in the area of the hydromassage bathtub and shall not be required to be extended or attached to any remote panelboard, service equipment, or any electrode.


    As can be clearly seen there is no requirement for connecting this #8 to the grounding electrode at all except what the manufacturer is saying and saying in error in my opinion.

    As a student of electrical theory myself I will say in no terms would I connect my tub to the electrode conductor no matter what the manufacturer had to say about the matter. Any well versed electrician will tell you that every electrode conductor installed will carry some current. If what I was looking to accomplish was to keep everything in my area at the same potential I wouldn’t connect to anything which would be carrying current.

    Do a Google search of the Faraday Cage, this is what you are wanting to accomplish with the bonding around any body of water be it a tub or a pool.
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