Hot tub electrical hazard?

Discussion in 'Homebrew and Kit Projects' started by KI6LNG, May 5, 2012.

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  1. KI6LNG

    KI6LNG XML Subscriber QRZ Page

    Hey folks,

    I just upgraded my old hot tub with a new PID controller. My tub is a 240v 60a service. My PID required no more than 120 volts so I took it from one hot and what I thght was the neutral bus. Looking closer at the schematic, it appears I may have conncted to a ground bus. My tub has 2 hots and a white wire which terminates to the neutral bus in my main panel (I don't have a seperate ground bus in the main panel). My tub also has a ground rod near it which is bonded to the bus inside the tubs panel that I connected to. Both the bus in the tub panel and the ground rod are bonded to a stray current collector in the water. As you may have guessed, my tub is not equipped with a gfi as it was not code at the time. I have used the tub several times and haven't had a problem, but the more I look at the schematic the more I think what I added wasn't done right???
  2. K8MHZ

    K8MHZ Ham Member QRZ Page

    I am a licensed electrician.

    PLEASE have an electrician come over and take a look at what you have done. You are fooling with stuff you should not be messing with. That is evidenced by the fact you posed such a question on a ham radio Internet forum.

    What is a human life worth?

    If the electrical inspector in your area is a decent guy I'll bet he would come out for about 50 bucks and make sure your wiring isn't such that it may pose a hazard.
  3. KI6LNG

    KI6LNG XML Subscriber QRZ Page

    I think for the time being I will just power the PID from a separate 120volt GFI outlet. Both the PID and the outlet are situated about 15' from the tub. With it setup this way, the relay in the PID is only switching 7 volts from the tub's solid state control panel. The reason i asked here is because I find that hams often know more about electrical theory than your average wire puller. I have attached a schematic if anyone cares to look at it... Schematic.jpg
    Last edited: May 5, 2012
  4. KO6WB

    KO6WB Premium Subscriber QRZ Page

    There are some that will tell you there is no difference between ground and neutral. Well sort of right, they are at the same potential usually in a residential environment. That's where the simularity ends. The ground is intended to be just that, it must not carry any of the current from any circuit. So you have a problem right from the start by using the ground in an improper manner. You need some serious inspection of your system and it would be in your best interest to bring it up to code. The code says if you do nothing to the system it can remain as is, however, if you do any maintenance on it then you must bring it up to current code.
    An example is if you have a conventional 120VAC outlet in your bathroom it can remain there. It's not a good idea but it's okay for now. If something happens to the outlet and it needs to worked on then it must be upgraded to a GFCI outlet.
    Get the assistance of a professional and if you're still in the DIY mode then make sure you follow the instructions of the professional exactly. Use an audio recorder to get everything that is said. With a notepad you may miss something important.
    BTW your average wire puller knows more about the code than an amateur radio operator would.
  5. KA9JLM

    KA9JLM Platinum Subscriber Platinum Subscriber QRZ Page

    I would put the Tub on a GFCI Breaker as a minimum.

    You could use a stepdown transformer for the PID, to keep from needing to add a neutral.
  6. W9GB

    W9GB Ham Member QRZ Page

    Many competent licensed (and bonded) electricians are not radio amateurs ... IF you are asking laborers pulling wires or apprentices -- you are consulting the WRONG sources.
    Who did you consult on this PID upgrade??

    Water and electricity can be quite dangerous ... The National Fire Prevention Association (NFPA) has revised the National Electrical Code (NEC) with more compliance additions in this area (e.g. Hot tubs, bathrooms, GFCI) to increase fire, electrical, and home safety over the last 50 years.
    NFPA 70
    Adopted in all 50 states, the NEC is the benchmark for safe electrical design, installation, and inspection to protect people and property from electrical hazards.

    Mark, W8MHZ has provided you advise to follow.

    I lost a cousin, who was electrocuted as a teenager, due to a Idiot doing Hillbilly electrical wiring in the 1950s. My uncle never fully recovered from this tragic loss.
    This is one area of technology that I have a LOW threshold for lame excuses, stupidity, and laziness.
    Last edited: May 7, 2012
  7. K8MHZ

    K8MHZ Ham Member QRZ Page

    I agree with what you are trying to say, but here are some minor corrections. No biggie, but my call is K8MHZ. W8MHZ belongs to a guy named Silvan.

    The NEC has not been adopted for residential wiring in all 50 states. Some use the IRC (International Residential Code). There are differences between the two. California has it's own, the California Electrical Code.

    Sorry about the loss of your cousin. 99 percent or more of electrocutions are preventable IF and only IF people will follow the rules.
  8. K8MHZ

    K8MHZ Ham Member QRZ Page

    Here are the rules for San Diego. I'll bet that most of the state has rules similar to or exactly like SD.

    It sounds like the OP is trying to install a "hard wired" controller. (As opposed to UL listed, factory installed cord and plug connected one). If so, a permit must be pulled before the work is done and an inspection must be done after the work is done, but prior to the installation being used.
  9. K8MHZ

    K8MHZ Ham Member QRZ Page

    You are recommending a 240/120 transformer to the OP?

    BAD BAD BAD advise!!

    Who would be the one to size the transformer?

    Who would be the one to do the AIC calcs do assure that the OCPDs can be sized accordingly?

    Would the transformer be considered a separately derived system and thus bear the grounding and bonding requirements of an SDS?

    How is a person that doesn't know enough to tell the difference between a ground and a neutral at first glance become skilled enough to install a transformer?

    Who would be testing the transformer prior to it's being energized?

    Would the transformer be subject to permits and inspections? (YES)
  10. KA9JLM

    KA9JLM Platinum Subscriber Platinum Subscriber QRZ Page

    The transformer operates a low voltage circuit.

    And may even have a tap to change voltage already on it.

    That would be better than using the ground as a current carrying conductor that goes against NEC.

    I agree this type of work should be inspected by a professional. GFCI is a must.

    Electric power used around water is no fooling mater.
  11. K8MHZ

    K8MHZ Ham Member QRZ Page

    The OP said that he needed 120 volts for his control system. A transformer that provides anything less (low voltage) would not work.

    As per the 2008 NEC, GFCI's are required for both the 240 volt circuit and the 120 volt circuit.

    The NEC is a bare minimum. The specs in the NEC will provide for (allow) the worst installation allowed by law.

    Exactly and bears repeating.
  12. K8MHZ

    K8MHZ Ham Member QRZ Page

    Is the white wire connected to a ground lug inside the hot tub panel? Meaning, the white wire is being used as a grounding conductor instead of a neutral?

    If so, that has never been permitted. Don't take my word for it. At least call your local inspector and ask about that. Grounding things with a white wire is bad. I would also be suspect of the entire installation if I saw something like that.
  13. KA9JLM

    KA9JLM Platinum Subscriber Platinum Subscriber QRZ Page

    "My tub has 2 hots and a white wire which terminates to the neutral bus in my main panel (I don't have a seperate ground bus in the main panel)."

    That sounds like a older home before a separate ground wire was Required.

    But the diagram provided by the OP shows that a Ground wire is required.

    It looks like the original Tub install was not up to code when it was installed.

    Insurance will never pay off if someone does get hurt unless you do it right and then get it inspected.

    Be careful playing with electricity, It can be a shocking experience.
  14. K8MHZ

    K8MHZ Ham Member QRZ Page

    I'll second that.
  15. G4COE

    G4COE Ham Member QRZ Page

    Murphy law states, "If anything can go wrong it will" and you don't wanna be scrubbing your back should Murphy appear...

    he could appear tomorrow, next week or when ever, might never appear at all!

    You wanna risk a fatality because you were told so..... should a fatality occur because of faulty workmanship - at least they'll be in 'hot water' and no one else with a severe claim pending.

  16. K6ABZ

    K6ABZ Ham Member QRZ Page

    Personally, I'd also install a GFCI breaker for this thing at the panel, just to be on the safe side.

    As far as powering the tub: I've done a lot of installations of 240v appliances, and I've never had to put in a neutral except when the appliance has some components that operate at 120v and others that operate at 240v. However, I'm not an electrician, and don't think my advice is anything other than friendly suggestions.

    I think I'd play it on the safe side and power your device externally, the way you're doing it now. Without a neutral, you don't have a redundant path to ground if your neutral wire fails for some reason. To do it totally right, you should probably run a new, dedicated circuit for your PIC.

    Tapping in to your existing circuit to power your PIC presents another problem nobody has mentioned: you don't have a 20A breaker out there, so you can potentially draw more than 20 amps through the outlet - starting a fire.
    Last edited: May 18, 2012
  17. K6ABZ

    K6ABZ Ham Member QRZ Page

    Did you look at the circuit diagram? The tub doesn't have any 120v components, so no neutral wire is required (at least based on the tub's electrical requirements). There's a local ground - the stake the OP mentioned, and there's a ground lead going back to the breaker panel. This is all in accord with all of the 240v stuff I've ever installed.

    Now he wants to add a 120v component to this system: this requires a fourth wire, a true neutral (not a ground). He can either pull a new wire through the existing conduit, or he can power the new component off a nearby AC outlet - which is what he's done, and it's probably the simplest way to go.
  18. KA9JLM

    KA9JLM Platinum Subscriber Platinum Subscriber QRZ Page

    Yes I did.

    It seemed that some confusion was whether it was a ground or a neutral.

    To do it correct it would need 3 current carrying conductors and a ground if a 120V circuit is also used.

    And a GFCI should be used.
  19. K6ABZ

    K6ABZ Ham Member QRZ Page

    A agree that he needs 4 wires if he's going to use 120v for anything.

    But I don't agree that this installation was not up to code. If I understand things correctly, you only need a neutral if you have any 120v components in your system. Otherwise, you only need the two hots and a ground.

    Of course, things could have changed recently, and I'd always run 4 wires just to make sure I could have an outlet there, but that's just my personal preference. When it comes to having outlets or data jacks, you can never have too many.
    Last edited: May 18, 2012
  20. K8MHZ

    K8MHZ Ham Member QRZ Page

    AS the OP is describing it, a white wire is being used as an equipment grounding conductor. That is a violation and has been for many code cycles. Since the hot tub needs and has no provisions for neutral, the white wire should not be there. Instead, the wire to the ground bus should be either green or bare. Also, if the tub is wired with multi-conductor cable, it is not acceptable just to pull another wire in. All conductors must be in the same cable.
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