ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Shout Box
Recent Posts
Changing a Bulb
by gfretwell. 07/14/18 03:12 PM
Tray cable?
by gfretwell. 07/11/18 10:18 PM
Eaton Heavy Duty 30A and 60A Safety Switches
by Admin. 07/11/18 09:49 PM
ORTOVOX Recalls Avalanche Transceivers
by Admin. 07/11/18 09:44 PM
Tingle off the water spigot
by gfretwell. 07/08/18 12:58 PM
New in the Gallery:
Plug terminals
Housebilding DIY wiring
Who's Online Now
0 registered members (), 35 guests, and 17 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Page 1 of 2 1 2
Hot Tub Problems HELP!!!! #168081
08/26/07 08:56 PM
08/26/07 08:56 PM
A
AWL  Offline OP
New Member
Joined: Jul 2007
Posts: 9
NH
I hooked up a moved hot tub that a friend of mine had given to him. I hooked it all up and left. He got it filled and turned on the circuit for the heaters and it immediately tripped. I returned and swapped the gfi breaker out for a regular breaker and it held so now Im lost is it the gfi bad or something else?

Work Gear for Electricians and the Trades
Re: Hot Tub Problems HELP!!!! [Re: AWL] #168083
08/26/07 09:50 PM
08/26/07 09:50 PM
renosteinke  Offline
Cat Servant
Member
Joined: Jan 2005
Posts: 5,316
Blue Collar Country
I suggest you start looking for the place where curerent is leaking.

Re: Hot Tub Problems HELP!!!! [Re: renosteinke] #168089
08/26/07 10:00 PM
08/26/07 10:00 PM
A
AWL  Offline OP
New Member
Joined: Jul 2007
Posts: 9
NH
I just looked at it quick and assumed that it was a bad breaker the breaker was a used(like the tub) 30 amp dp gfi. It has to be something internal on the tub its only when then heaters are turned on with the gfi breaker in. and no i didnt keep it hooked up with that breaker in there

Re: Hot Tub Problems HELP!!!! [Re: AWL] #168093
08/26/07 11:16 PM
08/26/07 11:16 PM
R
Rewired  Offline
Member
Joined: Jan 2006
Posts: 558
Hamilton, Ontario, Canada
Only trips when there is a call for heat? COULD be the control circuit for the heaters but I doubt that, I am gonna call it being the heating element itself

A.D

Re: Hot Tub Problems HELP!!!! [Re: Rewired] #168098
08/27/07 01:56 AM
08/27/07 01:56 AM
TOOL_5150  Offline
Member
Joined: Aug 2007
Posts: 61
Bay Area
I did somewhat of the same job for a friend and the GFI was tripping as well. Turned out the heater element had burned through the box it was in and had rusted the control circuit box. Ended up buying a new spa pack. Then found out a pump had seized. Friend decided to can the whole project. Just glad I didnt pay for the wire! Also - The spa I worked on had some sort of ionizer that was hooked to a relay that let the smoke out when I turned the breaker on. Never put money into a free spa off craigslist!

~Matt



I would rather beg for forgiveness then beg for permission.
Re: Hot Tub Problems HELP!!!! [Re: TOOL_5150] #168129
08/27/07 04:33 PM
08/27/07 04:33 PM
C
ChicoC10  Offline
Member
Joined: May 2007
Posts: 169
CA
I'm no expert on spas but it seems if you disconnected the heater terminals, power off of course and measured with a good ohm meter (not somthing like a Fluke T6 that only goes up to 1K) you should see a very high resistance between each leg and ground. My guess on the math, please correct me if I'm wrong, would 120/.005=24K ohms to trip a 5 miliamp GFI.
I recently read here that the GFI breakers have a higher tolerance, around 30 miliamps so that would be 120/.03= 4K ohms.
I guess that would assume a single point of leakage right in the middle of the element though.
With leakage right at one end of the element it would be 240/.005=48K for the 5 mili and 240/.03=8k for the 30 mili.

Would it be true that with a 30 miliamp GFI it should be possible to tolerate down to as low as 4K between a hot leg and ground before she blows?
Vince

Re: Hot Tub Problems HELP!!!! [Re: ChicoC10] #168143
08/27/07 08:55 PM
08/27/07 08:55 PM
G
gfretwell  Offline

Member
Joined: Jul 2004
Posts: 9,242
Estero,Fl,usa
Actually if you had a dead short to ground right in the electrical center of the element it would not show a ground fault unless there was unbalanced current from other equipment on the circuit.
The volts to ground is highest right where the connection to the element is and that is 120v nominal.

Think about a multiwire circuit.


Greg Fretwell
Re: Hot Tub Problems HELP!!!! [Re: gfretwell] #168147
08/27/07 10:59 PM
08/27/07 10:59 PM
C
ChicoC10  Offline
Member
Joined: May 2007
Posts: 169
CA
My question was structured around trying to test the element by means of unpowered, open circuit resistance measuring to determine if it were the cause of a GFI trip. That lead me to wondering just how much leakage would be possible without tripping the GFI. Again, I am no expert.
However voltage wise I would have to agree with what your saying. Assuming good bonding you wouldn't even feel it, if the element remained stable in that "center tapped" state of failure. Kirchoff and the superposition theorem both say that there would be no leakage under that condition.
I overlooked that in my original question, even though I used dead center as my first example. Oops.
I guess at that point you would need the manufacturers specs on resistance between L1 and L2 and if you measure 1/2 of that between either lead and ground then that must be the case.
Scary. But how probable? The center of the element would have the lowest tension to ground if I'm thinking straight.
It seems more likely to fail where the tension was higher, more toward one of the ends.
But it wouldn't trip at the center without 120V loads to imbalance it so it's probably not AWL's problem and he could still have an off center fault that could explain the tripping. Of course a non-tripping spa could have an imbalanced failure as above being balanced by 120V loads so all appears good!
I'm never getting in one of those things again!!!
Probably best to just get the specs and test properly.
Thanks for the insight.
Vince

Re: Hot Tub Problems HELP!!!! [Re: ChicoC10] #168149
08/28/07 12:07 AM
08/28/07 12:07 AM
B
BigB  Offline
Member
Joined: Mar 2004
Posts: 725
Tucson, AZ USA
Why don't you just unhook the heater leads then see if the breaker holds?

Re: Hot Tub Problems HELP!!!! [Re: BigB] #168194
08/28/07 08:02 PM
08/28/07 08:02 PM
C
ChicoC10  Offline
Member
Joined: May 2007
Posts: 169
CA
No, that would be too easy:)
That should let you know if an element replacement is necessary but I always get nervous swapping expensive and difficult to access parts without knowing for sure that I need to.

But I'm still wondering how much leakage the average GFI breaker you would find protecting a spa would let through before tripping.

Page 1 of 2 1 2

Featured:

2017 Master Electrician Exam Preparation Combos
2017 NEC Electrician
Exam Prep Combos:
Master / Journeyman

 

Member Spotlight
Lostazhell
Lostazhell
Bakersfield, CA (Originally Orange Co.)
Posts: 1,431
Joined: February 2004
Show All Member Profiles 
Top Posters(30 Days)
Admin 5
Popular Topics(Views)
248,123 Are you busy
185,580 Re: Forum
174,900 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.6.1
(Release build 20180101)
Page Time: 0.031s Queries: 16 (0.011s) Memory: 1.0266 MB (Peak: 1.2073 MB) Zlib enabled. Server Time: 2018-07-19 03:40:44 UTC