|
| Ek's Home | Forum | Chat | Electrical Links | |
| Subject - Seeking Advice - GFCI breaker constantly tripping | |
| nertz |
The GFCI breaker for my hot tub is constantly tripping (on average twice per week, as often as daily). The GFCI is in my main load center (2-pole 40A, 5mA sensitity Class A). Hot tub is about 60ft downstream hard wired with 6/3, with a exterior service disconnect in between about 15 ft of wiring from tub. Exterior wiring is all in 1" PVC conduit, about 10ft of it beneath ground. Load currents measured at load side of GFCI is 0.5A idling, 15A with heater on, 26.5A with heater and jets on, and in all cases less than 0.5A un-balance (neutral current). Heater is rated at 4kW, jet pump 4-hp, and main circulation pump at 1/3-hp. Manufacturer's manual suggested 240V/40A circuit. I'm reasonably certain the trips are ground fault and not overload. It will trip unexpectedly anytime whether in use or not. Area beneath the tub with motors and connections to spa pack is dry with no signs of moisture and no signs of pest or rodents. Would appreciate any advice that might reduce frequency of trips. Are GFCIs sensitive to high frequency interference, and if so would shortening the length of wiring between GFCI and load make a difference? Reason I ask, while making the current measurements I used a radio with my son giving him instructions to turn on jets/heater. First time I keyed the radio while standing next to load center breaker tripped. Appreciate any advice from the experts.... thanks. |
| MSD | Most likely the heater element is corroding/shorting out due to inproper PH balance in the spa. Disconnect the leads going to the heater and see if the GFCI holds. If so replace the heating element.quote: The above statement leads me to think that your troubles are happening when the spa turns on "automaticly" to maintain temperature. |
| lctrc789 | I have to agree with MSD here, chances are something internal is causing your problem, I would do as he suggested and see if it trips, this might be your culprit. GFCI s are very sensitive and at .05 milliamps that isn't much and the heater elements may be corroded enough to cause them to show that much difference and trip them out. |
| nertz | MSD & lctrc789, Thanks for the advice. Bad time of the year to try disconnecting the heater, but I will have it replaced by spa dealer this week and see what happens. Had not really thought that water balance might be a problem, but I do check chemical balance regularly and make the necessary adjustments as required and never let PH go below 7.0, typically sits 7.4-7.6. Makes sense tho that water balance may cause such problems. Had reset the breaker again last wednesday evening, left thursday morning and came home sunday evening after 4 days absence to find the breaker had tripped again. With water temp at 65 deg. F down from 102 and outdoor temps hovering around 25-35 deg F, I figure it had tripped sometimes within the past 24-48 hours. Thanks all... |
| nertz | Well..... Searching on the web I came about this recall notice from the US Consumer Product Safety Commission, which applies to my hot tub. Kinda disappointed that as a registered owner I had not been notified. I don't know enough about motor run cap failure modes, but I'm starting to suspect it may be the culprit to the nuissance GFCI trips. But before I invest in a not necessarily needed heater replacement, I want this fixed first. |
| nertz | Update: Had a serviceman come and look at the tub. The recall notice did not after all apply to my tub. After looking over at all the equipment and running the diags on the spa-pack, the serviceman found nothing wrong with the tub or its equipment, and pointed to my problem being the GFCI breaker (FP stablock NAGF-240 Class A 5mA sensitivity device) in my main load center panel. This serviceman showed a strong dislike towards FP load centers. If water chemistry had caused heater corrosion and the frequent GFCI trips, the serviceman said that I would not be able to reset the breaker, it would trip immediately again unless all the moisture between the heating element and its casing would completely dry. He replaced the GFCI in my main load center with a regular 2-pole 40-Amp breaker, and installed a GFCI breaker (Cutler-Hammer 40-Amp 2-pole GFCI) in place of the 40-Amp breaker in the service disconnect box outside (Type 3R box). Since then over 96 hours ago, I have not experienced a single trip even with this extremely cold temperatures we've had this weekend and with the same heating element and pump motors cycling on and off. Up until he came, it would trip quite regularly within 24-36 hours of being reset. Brings me back to the original question: Are GFCI's sensitive to the length of the circuit downstream to the load, perhaps sensitive to RF? +Nertz |
| JimmyDee | quote: Can not imagine anyone with a conscience installing one of these load centers in a house. They are right there with the old Push-A-Matics. I have not known them to be sensitive to high frequency interference or length of run but I do have 2 GFCIs in my bathroom that trip, every 10th time I shut my bathroom fan off. Maybe the motors in the pumps cycling on and off caused the GFCI to trip.  Jim |
| nertz | Jim, thanks for your comments. But I'm curious....quote: Jim, from your experience are those panels bad news? 17-yr old house, all houses in neighborhood have these, probably installed by same electrician 17 yrs ago. I sense you dislike them too. quote: The one pump (recirculation pump, 1/3HP) is always on. Jet pump (4HP) does cycle every 4 hours normally, 2 hours when tub equipment area temp falls below 40 def. F, or turned on on-demand when using tub. Both motors are 240V, jet pump is a capacitor start, and neither motor has a neutral lead. If cycling on/off caused GFCI to trip, that means some current (Class A: 5mA for min 5mSec duration) must have shunted to ground, right? How is that possible on an intermittent basis? Why doesn't it occur now with a different GFCI breaker located closer to the load? Actually, doesn't the cycling on/off of motors produce high frequency harmonics momentarily especially at startup? +Nertz |
| JimmyDee | Yes I have disliked the FP panels since I drove service truck a number of years ago. I carried one of every breaker on my truck and a half a dozen of each of the Fed Pac breakers and 6 Push-A-Matics. Yes IMO they are junk. quote: To answer this I will tell you up front that some of what I'm going to say is speculation but the experience is fact. Just follow me and you will see where I'm going with this. At a Paper mill I worked at, we kept having problems with ice cube relays that were failing. These relays had diodes to change the coil current to DC for noise elimination. These relays were wired in paralleled with either size 1 through 5 starter coils. We found that the failure was caused by the diode failure. Probably by over voltage that exceeded the PIV rating. Big question was where did this excess voltage come from. With recording equipment, we discovered when the size 5 starter was deenergized precisely at the peek of the sign wave, it produced a counter spike of about 1200 volts. This was a short duration spike that showed only a thin line on the graph but is was non the less there. Enough to blow the diodes out of the relays. (We installed MOVs across the relays and eliminated the failures by 100%) It is my speculation that the same type of counter spike is generated when a motor is deenergized as well. I know there is usually a heavy arc that is produced and seen from the switch. Under the same type of conditions we had with the starter coils I think the counter spike could be what causes the GFCI to trip. Not sure why or what is happening in the GFCI to do this but I'm sure it can happen. Length of cable could help cause this? I have not a clue. Jim |
| nertz | Thanks Jim, very familiar with spikes when coils are de-energized and arcs across contacts. This has possibility of becoming interesting conversation piece sometime later down the road.... For now, my problem appears solved for reasons I'll just have take as "FM" (ie: F@#$#$ Magic/not the radio waves). Thanks for all the comments. cheers, +Nertz |
| sammyg | I am constantly replacing Ferderal Pacific panels for people, due to the hazard they create. Just do the research and see why so many people are against this outdated company that is no longer buisness. |
| Energreen | I read about a recall on the Federal Pacific panels years ago. Sorry, I don't remember any specifics. The thing that stuck in my memory was the cause for the recall. Fires. |