Hot tub electrical hazard?

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

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  1. KI6LNG

    KI6LNG Ham Member 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 Ham Member 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 Ham Member 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 Ham Member 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.
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