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Home > Archive > Electrical Engineering > July 2005 > Hot Tub and GFCI
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| I obtained a used hot tub with all the plumbing, pump, heater, and
control box, for free (we had to haul it). I built the deck, and
hooked everything up. I ran conduit from the breaker box to the deck
and wired everything according to code, but the GFCI breaker kept
tripping. The only possible leakage path I could find was some rusting
around the seal where the heater wires connected to the actual heater
element.
Could this small amount of corrosion allow enough leakage current to
trip the GFCI??
If so, can I apply some Naval Jelly, or CLR, etc. to get rid of it?
My other option is to simply buy another heater and/or control unit,
but that would have to wait until next year.
In the mean time we are enjoying the tub on a non-GFCI 40-Amp breaker,
and I can neither measure any current (with a multimeter from water to
earth/deck), nor feel any "tingles" when we use it.
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| Roy Q.T. 2005-06-28, 6:25 pm |
| hmph!
i don't think the rust has anything to do with it, unless the leads to
the elements you mentioned are touching the corroded spot., may be in
the actual wiring scheme from the gfi breaker (i wouldn't feel safe
without gfi protection), have it checked by a qualified electrician
a.s.a.p. before & just in case anyhing else goes wrong GF....=AEoy
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"tlbs" <tlbs101@excite.com> wrote in message
news:1119980693.479186.135010@o13g2000cwo.googlegroups.com...
quote:
> I obtained a used hot tub with all the plumbing, pump, heater, and
> control box, for free (we had to haul it). I built the deck, and
> hooked everything up. I ran conduit from the breaker box to the deck
> and wired everything according to code, but the GFCI breaker kept
> tripping. The only possible leakage path I could find was some rusting
> around the seal where the heater wires connected to the actual heater
> element.
>
> Could this small amount of corrosion allow enough leakage current to
> trip the GFCI??
>
> If so, can I apply some Naval Jelly, or CLR, etc. to get rid of it?
>
> My other option is to simply buy another heater and/or control unit,
> but that would have to wait until next year.
>
> In the mean time we are enjoying the tub on a non-GFCI 40-Amp breaker,
> and I can neither measure any current (with a multimeter from water to
> earth/deck), nor feel any "tingles" when we use it.
\
Corrosion usually is not the problem. Leakage is what the ground fault
measures.
You connected this unit up with ????? 2 hots, a neutral and a ground wire
(#10).
Will the spa run with out the heater on the gfci? Where is the gfci? in the
panel?
Please forward your name and address to me so I can take out some life
insurance.
Enjoy away, not that I would want anything to happen to you or yours. Do you
realize that if an accident was to happen and some one got hurt, you would
probably get a free ride to jail?
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| The GFCI says you have an electrical problem. You have a
potentially danagerous electrical problem. Not a rust
problem. Not something that chalking will solve. You have a
wiring problem that may eventually kill. The GFCI is saying
this very loudly. There is no other answer.
Also scary: you are looking for excuses rather than
listening to what the GFCI is saying.
tlbs wrote:
quote:
> I obtained a used hot tub with all the plumbing, pump, heater, and
> control box, for free (we had to haul it). I built the deck, and
> hooked everything up. I ran conduit from the breaker box to the deck
> and wired everything according to code, but the GFCI breaker kept
> tripping. The only possible leakage path I could find was some rusting
> around the seal where the heater wires connected to the actual heater
> element.
>
> Could this small amount of corrosion allow enough leakage current to
> trip the GFCI??
>
> If so, can I apply some Naval Jelly, or CLR, etc. to get rid of it?
>
> My other option is to simply buy another heater and/or control unit,
> but that would have to wait until next year.
>
> In the mean time we are enjoying the tub on a non-GFCI 40-Amp breaker,
> and I can neither measure any current (with a multimeter from water to
> earth/deck), nor feel any "tingles" when we use it.
| |
| DaveB 2005-06-28, 11:25 pm |
| On Tue, 28 Jun 2005 12:26:42 -0700, "SQLit" <sqlit@qwest.net> wrote:
quote:
>
>"tlbs" <tlbs101@excite.com> wrote in message
>news:1119980693.479186.135010@o13g2000cwo.googlegroups.com...
>\
>
>Corrosion usually is not the problem. Leakage is what the ground fault
>measures.
>
>You connected this unit up with ????? 2 hots, a neutral and a ground wire
>(#10).
>
>Will the spa run with out the heater on the gfci? Where is the gfci? in the
>panel?
>
>Please forward your name and address to me so I can take out some life
>insurance.
>
>Enjoy away, not that I would want anything to happen to you or yours. Do you
>realize that if an accident was to happen and some one got hurt, you would
>probably get a free ride to jail?
>
If he was lucky enuff to survive
Regards
quote:
>
Daveb
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| John Ray 2005-06-28, 11:25 pm |
|
"w_tom" <w_tom1@hotmail.com> wrote in message
news:42C1B2D0.75A3479E@hotmail.com...[vbcol=seagreen]
> The GFCI says you have an electrical problem. You have a
> potentially danagerous electrical problem. Not a rust
> problem. Not something that chalking will solve. You have a
> wiring problem that may eventually kill. The GFCI is saying
> this very loudly. There is no other answer.
>
> Also scary: you are looking for excuses rather than
> listening to what the GFCI is saying.
>
> tlbs wrote:
I have wired several hot tubs which included a high current gfci inside the
control panel and *yes* it will trip a gfci mistakenly installed on the line
side. I should note that I have NO IDEA if this is your situation....Just
pointing something out.
John
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| On Tue, 28 Jun 2005 21:46:53 GMT, DaveB wrote:
quote:
>On Tue, 28 Jun 2005 12:26:42 -0700, "SQLit" <sqlit@qwest.net> wrote:
>
>
>If he was lucky enuff to survive
>
>Regards
>
>Daveb
No answer, maybe he didn't...
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| Clarification:
This is a 220V 3-wire + ground wire system. I have 4 #10 wires routed
from the panel to the Control unit (Black, Red (220V), White (neutral
return), Green (safety ground).
The GFCI breaker is a 220V breaker (2-slot), with a pigtail for the
neutral. I connected it according to the directions.
I am not trying to avoid "getting around" the rules altogether. I will
eventually have this fixed one-way-or-another so that the GFCI does not
trip when the tub is operating. I am just trying to find the source of
the problem, which I believe to be corrosion in contact with the heater
wires.
What other paths of leakage could there be?
Another thing to mention: With the unit disconnected, I tried to
measure (with a Fluke multimeter) paths for leakage. No matter where I
looked in the 220V circuitry, I always measured greater than 2 MegOhms
to the control case, the water, the motor case, cement patio, or nearby
earth ground. The GFCI is listed to "trip" at less (equivalent
current) than that -- much less than that (I'll have to go re-read the
manual to get the exact number).
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| You could try disconnecting the heater completely and see if the GFCI
trips. Same with heater, pump, ....
(Resistances to ground are more accurately measured with a "megger"
which uses a higher voltage.)
Bud--
tlbs wrote:
quote:
> Clarification:
>
> This is a 220V 3-wire + ground wire system. I have 4 #10 wires routed
> from the panel to the Control unit (Black, Red (220V), White (neutral
> return), Green (safety ground).
>
> The GFCI breaker is a 220V breaker (2-slot), with a pigtail for the
> neutral. I connected it according to the directions.
>
> I am not trying to avoid "getting around" the rules altogether. I will
> eventually have this fixed one-way-or-another so that the GFCI does not
> trip when the tub is operating. I am just trying to find the source of
> the problem, which I believe to be corrosion in contact with the heater
> wires.
>
> What other paths of leakage could there be?
>
> Another thing to mention: With the unit disconnected, I tried to
> measure (with a Fluke multimeter) paths for leakage. No matter where I
> looked in the 220V circuitry, I always measured greater than 2 MegOhms
> to the control case, the water, the motor case, cement patio, or nearby
> earth ground. The GFCI is listed to "trip" at less (equivalent
> current) than that -- much less than that (I'll have to go re-read the
> manual to get the exact number).
>
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| gfretwell@aol.com 2005-07-01, 4:25 am |
| On 28 Jun 2005 10:44:53 -0700, "tlbs" <tlbs101@excite.com> wrote:
quote:
>My other option is to simply buy another heater and/or control unit,
>but that would have to wait until next year.
>
\
I bet it is a bad element. These things are like a water heater
element and they can get some internal leakage. The element itsef is
grounded so the amount that actually leaks to the water is minimal but
it is dumb to take chances over a $15 part.
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| I thought I might have to use a megger to get an accurate resistance
reading -- unfortunately I don't have one, or access to one.
There are two contactor relays in the control box. One for the heater,
and one for the motor. I'll try and isolate the 2 and see what happens.
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| John Gilmer 2005-07-03, 11:25 pm |
|
quote:
>
> What other paths of leakage could there be?
The heater is the most likely suspect. Temporarily disconnect it ENTIRELY
and then see if the GFCI trips. There might be some crud when the power is
connected and this might provide the leakage path.
You might try "drying" the connections with WD-40. It might make just
enough difference to keep it from tripping out.
WD-40 can be a termporary "cure" for "weird" GFCI problems.
If the heater isn't the problem, you will have to keep disconnecting stuff
until the GFCI doesn't trip. Keep VERY good records of what you do so you
can get things back together again.
I think now you know why you got it cheap. It may well be that some unique
park is the cause of the failure.
A variation of this problems occurs when folks have a string of outside
outlets on one GFCI. Finding the problem can be a real PITA.
As others have posted it's quite possible that low voltage DC "leakage"
measurements will not pinpoint the problem.
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| Roy Q.T. 2005-07-04, 4:25 am |
| Hey' Another thing you might want to check out is:To make sure the GFI
circuit is stand alone for the Spa., If it shares the neutral with
another circuit in it's path it will trip also, but do something about
that rust and if you can place a grommet over the wireway entrance, or
use an insulating bushing or bladder type cable connector.
* Wires should not enter any machine or device box with out some type of
protection.Even a strain relief from another discard appliance would
help cover them from any further or future friction or damage..
Roy Q.T.
Urban Technician
[I don't make em, I just fix em]
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