johnnyt Posted November 20, 2012 Share Posted November 20, 2012 I have two devices that cause lights nearby to visibly vibrate or flicker rapidly and reduces the reliability of my insteon network - particularly the second device. The first one is a high end toaster oven that cycles its elements (very quickly) according to the setting it's on. Only on broil does it not cycle the elements (and runs at it's full 1800W). It's plugged into the stove on its own and we can see the rapid cycling in many lights throughout the house, including the fridge light - all different circuits. The other is a ~6 yr old Tripplite 1500VA UPS, which is more problematic in one way because it's always on and seems to cause more reliability issues but on the other hand I can only see the flickering when it's on the same circuit as the light. I don't know if the same principal is at play in both cases but is there a way to completely block out the flickering? Neither the 10 AMP filterlinc works (on the UPS anyway, I didn't try it for the 1800w toaster oven), nor does the 15A ACT AF120 filter. I seem to recall seeing mention of using a "choke" for things like low voltage lighting and CFL's but don't know if that's what would apply here or what size of choke to use if that's the case. I suppose I would have to build some kind of special outlet for these devices if that was the case. Any info would be appreciated. Link to comment Share on other sites More sharing options...
Brian H Posted November 20, 2012 Share Posted November 20, 2012 The toaster is making lights and circuits not controlled by an Insteon device flicker? You may have an electrical problem in your house wiring. Link to comment Share on other sites More sharing options...
johnnyt Posted November 21, 2012 Author Share Posted November 21, 2012 The toaster is making lights and circuits not controlled by an Insteon device flicker?You may have an electrical problem in your house wiring. Except for the fridge light, the lights that flicker are controlled by insteon switches. What kind of electrical problem(s) would cause that and would it not be the same situation for insteon controlled lights? Link to comment Share on other sites More sharing options...
TJF1960 Posted November 21, 2012 Share Posted November 21, 2012 Out of curiosity are the lights that are flickering CFL, Led, incandescent or fluorescent? Link to comment Share on other sites More sharing options...
johnnyt Posted November 21, 2012 Author Share Posted November 21, 2012 One fixture has some CFLs (on a KPL relay, FWIW), the fridge and the others are incandescent Sent from my iPod touch using Tapatalk Link to comment Share on other sites More sharing options...
Techman Posted November 21, 2012 Share Posted November 21, 2012 Have you measured your line voltage at various locations to see if that could be an issue? Link to comment Share on other sites More sharing options...
Brian H Posted November 21, 2012 Share Posted November 21, 2012 Flickering of lights not controlled by Insteon devices. Could indicate a poor connection and the voltage varying as the total load, the toaster, turns on and off. I can't say about the present hardware revisions. There was a hardware revision that was known to flicker with power line noise and fluctuations. Smartlabs changed a part to make them less sensitive to power line fluctuations. Link to comment Share on other sites More sharing options...
IndyMike Posted November 21, 2012 Share Posted November 21, 2012 I have two devices that cause lights nearby to visibly vibrate or flicker rapidly and reduces the reliability of my insteon network - particularly the second device. The first one is a high end toaster oven that cycles its elements (very quickly) according to the setting it's on. Only on broil does it not cycle the elements (and runs at it's full 1800W). It's plugged into the stove on its own and we can see the rapid cycling in many lights throughout the house, including the fridge light - all different circuits. Hello johnnyt, I'm in agreement with Brian - this is not a noise problem. Noise doesn't cause flicker in a normally switched incandescent bulb. It takes power to do that. Since you are seeing effects on multiple circuits, the problem is upstream from the panel. If these circuits are run from a sub-panel, check the connections between the main and the sub. If everything is on a main panel, you'll need to check from the main to the transformer (power Co time). Since the toaster is plugged into the oven, I'm guessing this is a 240V breaker on the main panel. A 1500VA load is not much to be causing these type of issues. It implies a rather bad connection - one that is probably generating heat. To further isolate things, please try the following: 1) Turn on your electric Range/oven (240V) and look for signs of a voltage drop. I'm betting you won't see anything since you haven't mentioned lights flickering with the 240V loads. 2) If you have a large 120V load (15 Amp) try activating this on various circuits while looking for drops. If you do not see a problem with the 240V load, but do with the 120V load, you have a neutral return problem. Could be between panels (if you have multiple panels) or between the house and the transformer. Neutral problem can be tricky to recognize. They become more evident when there is an imbalance in power draw between the phases ( Phase A drawing much more than Phase . Inspect (tighten if you are comfortable) the main connections at your panels. Then call the Power Co. Link to comment Share on other sites More sharing options...
ELA Posted November 21, 2012 Share Posted November 21, 2012 Hello johnnyt, With respect to the toaster oven. One explanation, assuming the flickering is in sync with when the toaster oven oscillated from on to off or visa versa: Our eyes are very sensitive to small fluctuations in light intensity. When a high current load such as the oven turns on and off repeatedly that causes an oscillating voltage drop in the house wiring that changes the light intensity. This is a very common occurrence in a lot of residences. Not to exclude other possible issues but experienced often. Measuring the voltages as Techman suggested would be prudent just to be sure the voltage dips are not too excessive. A laser printer is a common offender. My lights flicker ( Insteon or not) all the time when the printer is running. Not sure about the UPS. Is there a load plugged into it that might be turning on/off? Link to comment Share on other sites More sharing options...
johnnyt Posted November 22, 2012 Author Share Posted November 22, 2012 Great insights. Thanks. I just did some tests and here's what I found: Near the toaster oven is the stove with two separate 15A outlets and a split plug receptacle, with each plug going to it's own 15A circuit breaker. Using the two stove receptacles and the top split plug outlet results in lights flickering (vibrating, really). Using the bottom split plug outlet - no flickering. Then I used a Kill-a-Watt meter and took a voltage reading before and after turning the toaster oven on. The three outlets that flicker showed about 117V before and 114V after. I'm assuming that's reasonable but let me know if it isn't. The plug that doesn't flicker showed about 116V before and 110V after. That doesn't seem so good and is not what I expected from what I read here. If I understand correctly I may have a connection problem (with the neutral?) on the one outlet that actually doesn't cause a flicker... huh? Should I consider this a safety risk, particularly if I'm maxing out the circuit? Or could this damage what I plug into it? As for the Tripplite UPS, it was causing a flicker with nothing plugged into it (maybe trickle charging the battery?). This was several weeks ago and a similar APC UPS (1500VA) that's on that same circuit right now (behind a filterlinc) does not cause the lights to flicker. I ended up putting the Tripplite aside until this past weekend when I put it back into service on a different circuit. No lights flickering but my insteon network seems to have taken a hit. Could be coincidence. I'll have to run more tests with it but right now it's in a cramped closet powering a VMware ESXi server that's running VM's for my wife and kids so I will need to schedule some downtime on the weekend to do that. It's actually near the panel so it will allow me to check voltages at two plugs I have right off the panel. Link to comment Share on other sites More sharing options...
Techman Posted November 22, 2012 Share Posted November 22, 2012 A lot has to do with the size of the wiring to your plugs. 12 gauge wire will handle 20 amps, 14 gauge will carry 15 amps or 1800 watts at 120 volts. It's possible that you may be overloading your outlets at the lower voltage (114 volts x 15 amps = 1710 watts). Take a look at your voltages during the day with minimal load. You may also want to try taking a measurement close to your main panel. A bad connection, or faulty ground may also be a possibility. If you're located far away from the power company transformer that could also explain the lower voltage. You may want to have the power company come out and check to see if their transformer is overloaded. I had that problem many years ago and they installed a larger transformer closer to my home. Link to comment Share on other sites More sharing options...
ELA Posted November 22, 2012 Share Posted November 22, 2012 johnnyt, You are plugging the toaster oven into convenience outlets on a range? That does not sound like a good idea? If they are the type of outlets I envision they are probably intended for light loads. If they are on the range then the wiring to them may not be as large of gauge as one might expect. They may also go through some terminations inside of the range that can add to the voltage drop. A commonly mentioned acceptable voltage drop range is 3%. I would recommend running an 1800 W cooking appliance on a 20 amp circuit ( not through the range 15A convenience outlets). Can you try it on a 20A circuit and see if things improve? When you test for voltage drop be sure the unit is not cycling, or that the time at which you take a reading it is on 100%. Link to comment Share on other sites More sharing options...
johnnyt Posted November 22, 2012 Author Share Posted November 22, 2012 johnnyt, You are plugging the toaster oven into convenience outlets on a range? That does not sound like a good idea? If they are the type of outlets I envision they are probably intended for light loads. If they are on the range then the wiring to them may not be as large of gauge as one might expect. They may also go through some terminations inside of the range that can add to the voltage drop. The stove outlets indicate they are rated for 15 amps and each have their own 15A fuse. It seemed like a good idea because they're dedicated plugs. I didn't notice more than about a 3% drop in voltage for either of them, yet both cause the lights to flicker when used with the toaster oven on less than full load (i.e. cycling rapidly). I'll try a voltage test again at the full load setting to see what happens, as well as try other circuits in the house. Could there be something other than a bad connection going on? Can I have a bad connection without showing an excessive voltage drop? If the problem is upstream from the panel, as was suggested earlier, wouldn't all my outlets cause the lights to flicker? Would it depend on the overall load that the house is under, i.e. maybe I should test with the dryer and the oven on? Link to comment Share on other sites More sharing options...
TJF1960 Posted November 23, 2012 Share Posted November 23, 2012 When you turn the toaster oven on to full load do the lights flicker or dim once as it is turned on? Try it a couple of times as a test. I wonder if the cycling is not occuring at the zero crossing of the AC sinewave? Link to comment Share on other sites More sharing options...
ELA Posted November 23, 2012 Share Posted November 23, 2012 johnnyt, Sorry that I was hung up on your using the stove outlets for a load that is so large. Your flickering lights may be something different but your results from using a different outlet will eliminate the stove outlet question. A 1800 watt oven may draw 15 amps when on 100%. Even though your stove outlets are rated at 15 amp with a 15 amp fuse I would not necessarily recommend using them for the full 15 amp capability. (Depending upon how they are wired internally and what gauge wire is used internal to the appliance) In general when a home electrical system is designed it is not expected that any one device on a 15 amp circuit will demand all that the circuit is capable of. They install 20 amp circuits in a kitchen and dining room with the expectation that higher current appliances will be used there. From what you say it sounds like the Stove outlets experience less flickering so it might be best to eliminate it from this discovery process and focus on the flickering from some other 20Amp source. Link to comment Share on other sites More sharing options...
johnnyt Posted November 23, 2012 Author Share Posted November 23, 2012 wish I had a 20 amp circuit but I don't. maybe I can rewire stove outlet with 12 AWG wire and put in a 20A fuse? I can't I've ever looked in there to see if that's even possible. hope to be able to do some more testing over the next couple of days. Link to comment Share on other sites More sharing options...
johnnyt Posted November 25, 2012 Author Share Posted November 25, 2012 Did a bit more testing this morning. Despite what the manual and the tag on the toaster oven says (1800W), there's no setting that draws more than about 1550W (~13A). I also tested a 1500W heat gun and it draws about 1300W according to the Kill-a-Watt meter. Is it normal for electrical devices to claim a certain wattage but use less, or could it be that my Kill-a-Watt power meter is under reporting? When I use the highest setting on the Toaster Oven the lights don't flicker but the voltage drops about the same on the 4 outlets I'm using to test, i.e. ~3V on three of them, including the stove outlets, and about 6V on one of the split plug outlets. The voltage drop does not change whether the toaster oven is steady on or rapidly cycling the load. (all settings draw above 10A) I used the heat gun to check other outlets on the split plug circuit that has a 6V voltage drop and it's the same, suggesting the bad connection is either at the panel or on the way to the kitchen. I used the heat gun to check my two panel plugs, each one on a different phase and the voltage drop is only about 2 volts. Is that okay, or should it be closer to 0 at the panel? If okay, does that eliminate the likelihood of an upstream/utility company problem? As for the UPS, there's no noticeable voltage drop at all when I plug it into the Kill-a-watt. The test I did this time was with a ~125W load. Last time there was no load plugged into it. I don't see any lights flickering because of it and my insteon network has been okay so even though there was definitely something on the other circuit I was using I'll assume it's something about that one circuit and not a problem where it is now. Could it be the circuits for the lights that flicker that are the problem? One of them controls the lights in and around the kitchen, while the other, interestingly, is the one that saw lights flickering with the Tripplite UPS plugged into it (even though the APC UPS in it now does not cause any flickering). I'll check if/how pervasive the flickering is on other floors in the house tonight because I haven't done that. Link to comment Share on other sites More sharing options...
Slalom Posted November 25, 2012 Share Posted November 25, 2012 Did a bit more testing this morning. Despite what the manual and the tag on the toaster oven says (1800W), there's no setting that draws more than about 1550W (~13A). I also tested a 1500W heat gun and it draws about 1300W according to the Kill-a-Watt meter. Is it normal for electrical devices to claim a certain wattage but use less, or could it be that my Kill-a-Watt power meter is under reporting? [*:3n6t6i7e]A circuit should not be loaded beyond 80%.This means... [*:3n6t6i7e]A 15 amp circuit should never supply more than about 1500 watts[*:3n6t6i7e]A 20 amp circuit should never supply more than about 2000 watts [*:3n6t6i7e]When calculating load use nameplate ratings. When I use the highest setting on the Toaster Oven the lights don't flicker but the voltage drops about the same on the 4 outlets I'm using to test, i.e. ~3V on three of them, including the stove outlets, and about 6V on one of the split plug outlets. The voltage drop does not change whether the toaster oven is steady on or rapidly cycling the load. (all settings draw above 10A) That means that on the 3 outlets that drop 3 volts you are dissipating 30+ watts somewhere and on the 4th outlet that drops 6 volts your are dissipating 60+ watts somewhere. 14 gauge wire has a resistance of about .2525 Ohms per hundred feet. 12 gauge wire has a resistance of about .1588 Ohms per hundred feet. If you had a 75 - 100 foot run of 14 gauge and were drawing 10 amps 3 volts is not unreasonable for a drop. The toaster oven 'should' be on its own 20 amp dedicated circuit like a microwave. As regards the 'flickering' I expect that that has more to due with the waveform distortion (noise) than the actual voltage drop. Link to comment Share on other sites More sharing options...
ELA Posted November 25, 2012 Share Posted November 25, 2012 johnnyt, Can you please clarify what you meant when you said stove? Is it an electric oven? Or is it gas oven with convenience outlets? When I run a 1500 watt heater on each of the two outlets located directly at the service cabinet I register 1.5V drops. Link to comment Share on other sites More sharing options...
johnnyt Posted November 26, 2012 Author Share Posted November 26, 2012 johnnyt, Can you please clarify what you meant when you said stove? Is it an electric oven? Or is it gas oven with convenience outlets? it's an electric oven. Sent from my iPod touch using Tapatalk Link to comment Share on other sites More sharing options...
ELA Posted November 26, 2012 Share Posted November 26, 2012 johnnyt, It sounds like the one outlet where you experience the 6V drop might be of concern and you might consider having it investigated by an electrician. Back to what your original concern appeared to be with flickering lights. The fact that the electric oven is feed by a large gauge wire ( assuming 40-50A breaker) that provides a good low resistance path over most of the distance. A smaller gauge wire within the stove to the convenience outlets is where most of the additional ( above the 2V at the service) drop most likely occurs. None of this really seems to be much to discuss since you do not have any 20A outlets and appear to want to use the stove outlets. The voltage drop you see there is not all that excessive. Did you confirm that the flickering occurs at the same rate as the cycling of the toaster? If so then we are back to the fact that some "flickering" is expected when high current loads cycle on/off. Like the printer example I provided earlier. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.