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OT: Hot Tub GFI Beaker Pops

J

Jeff_M_PA

Cast Iron
Joined
Oct 31, 2008
Location
San Diego, CA
Outdoor hot tub about 5 years old, runs on a 30A 220V (single phase) GFI breaker.

Start of the season about a month ago, breaker popped once, reset, worked for 3 weeks. Then yesterday it popped again, won’t reset, so I need to troubleshoot.

Likely possibilities that come to mind are:

1) Bad breaker. I'm probably not that lucky, but it could happen

2) Bad heater, or other electrical component shorting in the tub. These heaters do go bad, had to replace one in a previous tub.

I could of course just buy a new breaker and if that didn’t work, then figure out what the problem is with the tub. I’m looking for troubleshooting advice. Is there a way to determine if the GFI breaker is faulty? Any other hints as I dig into this?

Jeff
 
Jeff_M_PA said:
Outdoor hot tub about 5 years old, runs on a 30A 220V (single phase) GFI breaker.

Start of the season about a month ago, breaker popped once, reset, worked for 3 weeks. Then yesterday it popped again, won’t reset, so I need to troubleshoot.

Likely possibilities that come to mind are:

1) Bad breaker. I'm probably not that lucky, but it could happen

2) Bad heater, or other electrical component shorting in the tub. These heaters do go bad, had to replace one in a previous tub.

I could of course just buy a new breaker and if that didn’t work, then figure out what the problem is with the tub. I’m looking for troubleshooting advice. Is there a way to determine if the GFI breaker is faulty? Any other hints as I dig into this?

Jeff
Click to expand...
Jeff,
Most common cause of this is a bad heater. You can test with an ohmmeter, but if you do not own one, simply disconnect the leads on the heater, tape them up so they do not short out, and see if the breaker resets. Keep in mind, you must remove both leads to the heater for this test. Second most common cause is water leaking onto an electrical component.

Steve.

Sent from my SM-J700P using Tapatalk
 
gbent said:
Worn out GFCI breakers are common.
Click to expand...
Not in hot tub circuits. I was a hot tub servicer for over 20 years. I've seen my share of defective double pole gfi's, and almost every one that failed, did NOT trip. They still passed power, but no longer had gfi protection. Pressing the test button would not trip the breaker. That's why it's highly recommended you periodically test the breaker.

Steve.

Sent from my SM-J700P using Tapatalk
 
Yeah but this is a GFCI breaker. You don't know if it is tripping due to ground fault or overcurrent. I'm not an electrician but I am required to use Gfcis on everything in my work. I hope someone with more knowledge than me will speak on this but what I would do is put a new, high quality in line GFCI in the circuit between the load and the GFCI breaker. Since it has no over current protection it will only trip due to ground fault. Or, there're cheap, just put in a new one and see what happens. Cheaper than that first hour with a sparky for sure.
 
tdmidget said:
Yeah but this is a GFCI breaker. You don't know if it is tripping due to ground fault or overcurrent. I'm not an electrician but I am required to use Gfcis on everything in my work. I hope someone with more knowledge than me will speak on this but what I would do is put a new, high quality in line GFCI in the circuit between the load and the GFCI breaker. Since it has no over current protection it will only trip due to ground fault. Or, there're cheap, just put in a new one and see what happens. Cheaper than that first hour with a sparky for sure.
Click to expand...
But that's just it, they're not cheap. A 220 volt, 50 amp double pole gfci is over a hundred bucks, and that's an expensive guess, especially if it ends up being a bad heater. The over current section of the gfi requires over 50 amps to trip, and that type of short circuit is rare in a hot tub. The gfi protection monitors current flow from the supply side to ground, and trips at only a very low current flow. When the heaters deteriorate over time, a small current starts to flow into the heater, and through the water to the heaters grounded body. The gfi senses this and trips when the thresh hold of around 6 miliamps, .001 amps, a tiny amount.

Steve.

Sent from my SM-J700P using Tapatalk
 
I'm with Steve. First thing I'd do is take the line out leads off the GFCI and see if it will set with nothing on it. If it will, the GFCI is good and something else is amiss. Then take components offline one at a time and see if the GFCI resets, starting with the heaters, next pump, etc... If it won't reset with something hooked up, that's your issue. Basic troubleshooting.
 
Guess I overlooked the fact that this thing heats the water along with blowing bubbly jets. Still about the same as a sparky saying "you need a $100+ breaker". Can you tell him a way to determine which it is? I know that breakers do wear/deteriorate with use. I have been told, maybe incorrectly , that using a breaker as a switch may cause it to evenbtually fail. Is this true?
 
Multi-meter and check the resistance of the heater coil to ground.

Make sure the breaker is OFF before you do anything - Verify this by checking for AC voltage at the breaker!

Then unhook the power leads to the heater to isolate it. Check heater coil to ground (not lead to lead), should show OL (open leg). If there is any resistance measurement, the heater is bad and needs replaced. It is imperative that you isolate it from the circuit though, your neutral and ground are tied together at the breaker panel so you will get false readings if they are not isolated. As mentioned above, a GFCI checks for current leakage to ground.
 
tdmidget said:
..... I have been told, maybe incorrectly , that using a breaker as a switch may cause it to evenbtually fail. Is this true?
Click to expand...

Yes, if it is not "switch rated", as some are. Most are not, and shutting off power with the breaker does it no good at all.

breakers are really not intended to operate very many times. They will work more times as a switch than they will if overcurrent tripped, though.
 
A GFCI does not "check for current leakage to ground", or "monitor(s) current flow from the supply side to ground".

The GFCI compares the current in the Hot leg to each other, and to the current in the Neutral, and makes sure that all of the current is accounted for. Any excess current is assumed to be flowing through something it was not intended to flow through(like a human body to ground).

You can install a GFCI without any ground wiring at all, and it will still function as it was intended to.
 
Thanks guys for all the responses. Stevewatr, I do of course have a multimeter. Awander, I think though your response to Tonytn36 is technically correct, if slightly pedantic in this setting, it amounts to the same thing, right? Your point is that it works without a ground, and you are correct, while I have a ground in this circuit the GFI does not monitor it. In fact, if you hook it up with the ground and neutral on the same bar, it will not work. Ask me how I know that…

So I should disconnect the heater and use a meter to test it to ground, and if it shows any measurable resistance, it’s bad. If it shows infinite resistance (OL – “Open Leg”. I’ve been looking at that on meters for 30 years and never knew what that meant, thanks Tonytn36!), then it MIGHT be good. Might also be bad and my GFCI is picking up those tiny milliamps but my meter isn’t. So if it tests OK, I’ll try and run it without the heater in the circuit, and see if the GFCI resets. If so, even with the minimal load of just the pump, I’ll figure the heater is bad. Which is almost no doubt what the problem is.

I just had to have a rotomolded Durasport Spa because I was in the recycling business and recycled all the PE from Strong Industries in Central PA.

durasport.jpg

I love the hard cover (which is extrusion blow-molded by the way), which is just brilliant compared to the usual thick pad system. But I must admit that from the start, the overall spa is not that great. The side panels are affixed with screws, and they are just randomly inserted into the insulation, and difficult to remove and reinstall. To drain it, it’s easier to pump the water out than to remove the panels and hook up a hose. There are numerous little plastic covers over hardware on it that just fall off periodically. And there are plastic bumpers on the bottom of the lid that broke so often I finally 3D printed replacements using a more flexible polymer, and mine have not broken. That all just adds up to company that cuts corners and isn’t all that concerned with making a quality product. So this presumed heater thing after such a relatively short time is just par for the course I guess.

Stevewatr, any hints on buying a replacement heater?

Jeff
 
Jeff_M_PA said:
Thanks guys for all the responses. Stevewatr, I do of course have a multimeter. Awander, I think though your response to Tonytn36 is technically correct, if slightly pedantic in this setting, it amounts to the same thing, right? Your point is that it works without a ground, and you are correct, while I have a ground in this circuit the GFI does not monitor it. In fact, if you hook it up with the ground and neutral on the same bar, it will not work. Ask me how I know that…

So I should disconnect the heater and use a meter to test it to ground, and if it shows any measurable resistance, it’s bad. If it shows infinite resistance (OL – “Open Leg”. I’ve been looking at that on meters for 30 years and never knew what that meant, thanks Tonytn36!), then it MIGHT be good. Might also be bad and my GFCI is picking up those tiny milliamps but my meter isn’t. So if it tests OK, I’ll try and run it without the heater in the circuit, and see if the GFCI resets. If so, even with the minimal load of just the pump, I’ll figure the heater is bad. Which is almost no doubt what the problem is.

I just had to have a rotomolded Durasport Spa because I was in the recycling business and recycled all the PE from Strong Industries in Central PA.

View attachment 213789

I love the hard cover (which is extrusion blow-molded by the way), which is just brilliant compared to the usual thick pad system. But I must admit that from the start, the overall spa is not that great. The side panels are affixed with screws, and they are just randomly inserted into the insulation, and difficult to remove and reinstall. To drain it, it’s easier to pump the water out than to remove the panels and hook up a hose. There are numerous little plastic covers over hardware on it that just fall off periodically. And there are plastic bumpers on the bottom of the lid that broke so often I finally 3D printed replacements using a more flexible polymer, and mine have not broken. That all just adds up to company that cuts corners and isn’t all that concerned with making a quality product. So this presumed heater thing after such a relatively short time is just par for the course I guess.

Stevewatr, any hints on buying a replacement heater?

Jeff
Click to expand...
Hi Jeff,
I was taught way back when that OL meant "out of limit", but I'll be the first to admit Tony may be right, and I may be wrong.

Next time I look at my Fluke manual, I see if they define it. Then again, differant manufacturers might even have another take on it. Either way, it means infinite resistance......oops, better not say that, it'll draw more fire for sure. I think we can all agree it means a resistance higher than the meter can display??

Anyhoo. Most hot tub heater assemblies have a replaceable element. I'm not familiar with the brand tub you have there, but it probably uses a common flow through heater. Just a straight stainless steel tube about 15" long. The element should be a tight loop, held in place by large nuts right around the electrical connections.

When you remove it, there should be a rating on it somewhere. Most common are 4kw. 5.5kw is typically only used on larger spas that are 220 volt only. I suspect your spa may be a 120/220 model. Most of the one piece plastic spas were. If it uses a load neutral, than it is.

Aftermarket elements are much cheaper than a whole heater assembly.

Here's an example of a typical one.

Flo-Thru Heater Element, Universal - Hot Tub and Spa Part

Some housings have 1 or 2 temp sensors that insert into them, and may interfere with installing the element, so try and match the shape of the bends to what you have there. Elements that mention m7 technology will usually fit housings with 2 temp sensors and no pressure switch.

Lastly, for a few bucks more, you can get improved coatings like teflon, tefel, or incalloy. They are worth it. I've used them for years.

Regards,
Steve.

Sent from my SM-J700P using Tapatalk
 
An ohmeter likely won't tell you if it is a ground fault tripping the GFCI because they are often capacitive in nature.

The standard test for leakage and I CAUTION YOU NOT TO TRY THIS unless you are comfortable working around live circuits is to insert a resistor between the electrical ground lead and the appliance and determine leakage current by the drop across the resistor. For 120vac the standard circuit is 1500 ohms shunted by a 0.15 microfarad capacitor. The capacitor is there to bypass higher frequency noise that otherwise might give incorrect readings. For 240vac you would double the resistance but the formula is still leakage current = voltage measured across resistor divided by resistor value in ohms. This is a "hands off" measurement that is done by connecting leads with the power switched off, energizing the circuit briefly to take a reading, and then switching off again to reconnect the earth ground.

If it is the breaker, it may be cumulative damage due to lightning or other surges as GFCIs are vulnerable to it.

The safer way is to take a ground lead measurement with a clamp-on ammeter that reads down into the milliampere range but I assume you don't have access to one.
 
Thanks again to Stevewatr, Tonytn36, Scottl, and everyone else that chimed in for the great info. I had only an hour today to dedicate to it and of course needed a small open-end wrench that I only had at work to get the damn element disconnected, and so will finish troubleshooting tomorrow. The controller and heater are well-marked and I am certain I'll not have trouble getting an element for it.

Scottl, I do have a clamp-on ammeter but not certain how low it will read. The drop across the resistor method is pretty brilliant, but I doubt I'll do that. If the breaker resets with the heater disconnected, that's likely the culprit.

I LOVE THIS BOARD!!! It is fantastic that I can post a question and get such helpful answers in a few hours. An amazing resource. A big shout-out to Milacron for bringing this little community together.

Jeff
 
A typical hot tub has several things that can fail and cause the GFCI to trip. Some are Motors , heaters, blowers , and lights. The best way I have found for my HT is to simply disconnect one device at a time, let it run for a while and then go on to the next. Since your fault is intermittent it may take a while. A resistance test to ground will not find the fault until it faults.....

The first item that I would try is the Blower if so equipped. BTDT..

There should be a circuit diagram on the control box cover which you can use to locate the wiring connection points.

3¢
 
So, to finish this tale, I figured out the problem today. After disconnecting everything but the board itself (there were 3 plugs into the board: I think pump, blower, UV sanitizer, plus the heater which was hard wired with copper strips) the breaker still would not reset. Disconnected the main power from the board, and it still would not reset. Damn, must be a bad breaker, as hard as that is to believe. Off to the Big Box, where for $93 I had to buy the enclosure and all. I could have probably saved a few bucks buying online, but it was warm today and I wanted to get this done. Installed new GFI breaker, and it immediately tripped. WTF?

I have a junction box in the line, where the wires I pulled underground in conduit switch over to flexible conduit that goes into the tub. The box is next to the tub about 6 inches above the ground. Took off the cover and water poured out. Inside was an ugly mess of corroded wire nuts. The box gasket was faulty (which just means I didn't install it correctly 5 years ago). Cleaned everything up and sealed box with silicone, plus drilled a weep hole in the bottom just in case.

So now I have a spare breaker and a spare heater coming from an online supplier, so I've got that going for me... But the tub is working fine, and the wife is happy again. Winters here in the 'Burgh are nicer if you can soak the chill out before bed.

Thanks again to all who contributed advice.

Jeff
 
How did it work out eventually for you with your hot tub? I followed your steps but the problem still came back after a week and I'm kind of clueless to why.
 
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