| Electronics > Beginners |
| SOLVED(4 separate problems!) Help with tripping GFCI and washing machine |
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| MyEEVBlogAccount:
EDIT: So far this seems to be fixed; see my later post for what is hopefully a permanent solution. Thanks for the help and suggestions. Before we begin, I want to mention that I am not an EE or electrician. We are doing renovations on part of our house, of which the electrical work is done and, I've been told, inspected. Ever since part of the "old work" was disconnected (which consisted of 5 regular outlets), the GFCI outlet that our washing machine was attached to started tripping during the same points in the cycle, with around a 25% probability. The trips always occur a split second after the top-loading washing machine stops filling due to the solenoid closing at either the initial fill or the rinse fill, but not when it is added for any other reason (e.g. permanent press). Subsequent to that development, the breaker that the circuit that the GFCI outlet is on was moved to another subpanel, as the old one ran out of room. Ever since then, it trips twice every cycle at the same points (e.g. when the solenoid shuts off after a long fill for initial and rinse). I've tried using an extension cord to try it on the other GFCI on the same circuit (they are in parallel and it normally has our primary sump pump and battery backup connected), which tripped itself AND the other one on the fifth test, but none of the prior ones. I've also tested it with the "new work" with an extension cord, but neither the new GFCI outlets nor the "AB breaker" (which I was told made the whole electrical compliant) it is connected to tripped during those tests. The general contractor is less then cooperative with the idea of checking it or calling out the electrician, for various reasons, and we are hesitant to force the issue. I've considered escalating it the issue, but if it was something simple to fix myself, I'd rather do that. Does anyone have any ideas of what I could try? Could it be the wrong kind of GFCI, if there are kinds? I've verified the outlet is wired correctly with a tester and, as mentioned, it worked before with the additional parallel outlets without problem. I've attached a basic diagram. Thank you for any help you can offer. |
| Richard Crowley:
I would simply replace the misbehaving GFCI with a new one. They aren't that expensive and it can't hurt. They DO age and go bad, after all. Or at the very least, swap the misbehaving unit with one of the new ones and perform some "differential diagnosis" to narrow down the cause. |
| MyEEVBlogAccount:
Yeah, I was thinking about just buying a new one, but the old one is only 9 months old or so. It just seemed odd that the problem cropped up and got worse as changes were made. But then again, coincidences do happen. Would any from https://www.menards.com/main/electrical/light-switches-dimmers-outlets/electrical-outlets/c-9526.htm?queryType=allItems&Spec_OutletType_facet=GFCI&sortby=priceAsc work or do you need something special? IIRC, the one currently there is this one https://www.menards.com/main/electrical/light-switches-dimmers-outlets/electrical-outlets/electrical/light-switches-dimmers-outlets/electrical-outlets/smart-electrician-reg-15-amp-self-test-gfci-outlet/9241-15iv/electrical/light-switches-dimmers-outlets/electrical-outlets/smart-electrician-reg-15-amp-self-test-gfci-outlet/9241-15wh/p-1490250024908.htm |
| soldar:
The clothes washer might be OK (for certain values of OK) and the GFCI might also be OK (for certain values of OK) but the combination of both might be marginal and it could be that swapping the GFCI might resolve the problem. The easiest thing is to begin by swapping that GFCI with another one and see what happens and what that may tell us. With that the problem may remain with the washer, it may go with the GFCI or it may disappear. Do this personally only if you have the knowledge and training to do it safely and without burning the house down or electrocuting yourself or others in the vicinity. I have some wonky experiences with GFCIs. Sometimes problems need a little detective work to diagnose correctly. Most appliances have some level of parasitic capacitive coupling between the live wires and the Protective Earth. It is usually low enough to not cause problems but if you have several appliances in parallel that small fault current can add up. Suppose you have a 30 mA GFCI and have 20 mA of parasitic losses. Now you only have a 10 mA margin. Suppose you have a GFCI which is specially sensitive and triggers at 25 mA. We are running near the limit and a small transient can trigger it. A motor or solenoid valve might have too high capacitive coupling with PE and depending on what moment of the cycle it is connected it could have an inrush peak enough the trigger the GFCI. Computer PSUs have capacitors to PE besides whatever other unintended losses they may have. Individually they may not be much but add up a whole bunch of appliances in a household and it may add up to near the GFCIs limit. Let me tell you a couple of stories. Note that the code in Spain requires Whole house GFCIs so only one GFCI for the whole house. This is a bad idea to begin with. Also note that we use Schucko plugs which are not polarized. Another bad idea. The problems I have encountered here would be greatly diminished or non existent in America. Some years ago a friend told me his home GFCI was tripping and, after some observation, he had determined it was always in the early afternoon when he was working on his computer and would lose a ton of unsaved work. After several hours spread over many days my diagnosis was that the apartment had several appliances with parasitic capacitive leaks and the general GFCI was running near its limit. One little spike and it would be triggered. The refrigerator, the clothes washer, the dish washer, the computer, all had ever so small so small individual losses which added up. This problem would not happen with several distributed GFCIs. Further investigation showed it was the dishwasher which was doing the final triggering as it did the dishes after lunch. Reversing the dishwasher's plug seemed to resolve the problem but I recommended he install two GFCIs in the general panel, one for the kitchen (where most of the losses were) and another one for the rest of the apartment. Another case, also some years ago, was that my own GFCI was also tripping and it seemed to be the clothes washer. Again, to make a long story short, the main cause was not the clothes washer but a toaster oven which had way to high parasitic losses and the clothes washer just added the tiny spike needed to trip the GFCI. The toaster over had (and still has) a resistance coil inside a metal tube and the capacitance between the resistance and the grounded tube was enough to have some serious capacitive loss which pre-loaded the GFCI. I further insulated the metal tube from the frame and housing with some tubing and that resolved the problem. In my apartment in Madrid I have the GFCI protecting kitchen and bathroom but not bedroom and living room. I consider that safer for my computer data and even though it does not meet the Code I consider it acceptable as there are no women, children or animals here. In my other house, which is much bigger, the GFCI protects the whole house and I have had no issues so far. Still, I have an induction cooktop which has relatively high leakage and, since I hardly use it, I keep it unplugged. Leaks to Protective Earth can sometimes be a bitch to diagnose. |
| Calambres:
I live in a three story house, being the two upper the "living" ones and the lower is a big garage where I have my "shop". I have one CFGI (automatic reset) for the two upper and another (manual reset) for the garage. I've had my own share of problems with CFGIs, which I reported in this topic, and one of the conclusions I extracted from my research is that the nominal mA of the CFGIs is not real but approximate, being always lower than indicated. If you sum up this to the facts Soldar just related in the previous post about summing parasitic capacitances in some of my electric appliances, my house is always on the verge of CFGI tripping. I'm also planning to add another CFGI to minimize the risks. In the cited thread I showed my DIY CFGI tester. |
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