EEVblog Electronics Community Forum
Electronics => Beginners => Topic started by: Mp3 on July 28, 2018, 11:17:35 pm
-
Hi everyone.... usually i have questions about repairing electronics but this time the problem is my condo...
My apartment has awful electrical wiring that is likely around 100 years old. Rewiring would be very destructive so i am not looking to do that for a place i will eventually move out of.
I have line conditioners on every outlet, so i have clean AC going to all my appliances, but i don't have as much control over things like my ceiling lamps.....
In my kitchen but no other room there are two lights that are a cluster of three lightbulbs. When you turn on the switch, both clusters turn on, so 6 light bulbs total.
For the first few years i was living here there were no problems. Starting last year I noticed some lightbulbs would die faster than others. It's now at the point where no matter what kind of lightbulb i put in (the old style incandescent or the new LED ones) all three bulbs will be dead within a couple weeks to a month.
I can't figure out why this would be a problem now but not in the past. I have a feeling there is an electrical problem that might be out of my control since the ceiling fan in one room (but not the other) stopped working around the same time the kitchen started burning out bulbs faster.
PS if it matters, the ceiling fans are Minka Aire branded, and i did check the troubleshooting for it. Pretty much the only thing i hadn't tried the troubleshooting guide suggested was cutting off the breaker to the whole condo for a minute and turning it back on, but this didn't fix anything.
-
If there were an electrical problem then you'd notice dramatic changes in brightness when using incandescent lamps.
What brand of bulbs are you using? the most likely culprit is cheap, poorly made bulbs. In the case of incandescent, vibration is a major killer but that shouldn't affect LEDs.
-
I'm assuming you haven't seen any light output differences of the various bulbs and that would be the first thing I would look for. I would next try one of the old fashioned screw-in adapters that allows you to plug a 2-wire cord into a lamp socket and check/monitor the fixture voltage with a meter for a while to see if the voltage is high or if you see occasional spikes. Some of the newer LED lamps that have what looks like a zig-zag filament have no electronics supply inside and might be more immune to overvoltage.
If you've noticed some lamps get brighter the same time some others dim it could be a high resistance neutral so instead of having 120-0-120, when the load isn't balanced the split might be 150-0-90 when a appliance like a fridge puts a heavy load on one side.
-
Hi everyone.... usually i have questions about repairing electronics but this time the problem is my condo...
My apartment has awful electrical wiring that is likely around 100 years old. Rewiring would be very destructive so i am not looking to do that for a place i will eventually move out of.
I have line conditioners on every outlet, so i have clean AC going to all my appliances, but i don't have as much control over things like my ceiling lamps.....
What do you mean by 'line conditioner'? A surge suppressor? Noise filter? Voltage adjuster?
In my kitchen but no other room there are two lights that are a cluster of three lightbulbs. When you turn on the switch, both clusters turn on, so 6 light bulbs total.
For the first few years i was living here there were no problems. Starting last year I noticed some lightbulbs would die faster than others. It's now at the point where no matter what kind of lightbulb i put in (the old style incandescent or the new LED ones) all three bulbs will be dead within a couple weeks to a month.
I can't figure out why this would be a problem now but not in the past. I have a feeling there is an electrical problem that might be out of my control since the ceiling fan in one room (but not the other) stopped working around the same time the kitchen started burning out bulbs faster.
The ceiling fan is suspicious. The power company could have rearranged the lines or adjusted the voltage. Spikes, surges, or too high a voltage can all kill bulbs or cheap speed controllers. Incandescent bulbs will burn out quickly if the voltage is too high. LED bulbs might be more sensitive to spikes or surges.
So what's your line voltage? Is it stable? You might have to monitor it over a period of hours or days to answer that. Do incandescent bulbs show any flickering or brightening/dimming? Have you torn apart any dead LED bulbs to see what blew up?
One thing you could try is to buy 130V bulbs. They might be called 'long life', 'rough service', etc. but check carefully to make sure they're 130V.
Ed
-
A poor neutral is what I'd check for too. The human eye is not very good at assessing absolute brightness, so an incandescent bulb running at 140 V won't look much different than one running at 120 V. But the one at 140 V will burn out dramatically quicker.
When you have a normal American domestic supply arrangement of 120-0-120 V with neutral in the middle, the neutral must be solid to keep each side at 120 V. If anything is wrong with the neutral there is the potential to have up to 240 V on an outlet.
-
I suspect the neutral too, especially since it seems to be getting worse. Something may catch fire soon (https://www.electrical-forensics.com/Open-Neutral/Open-Neutral.html) if it isn't looked into ASAP.
Life of incandescent bulbs is roughly proportional to the sixteenth power of the voltage. A 10% increase in voltage means bulbs that last 4.6x shorter.
-
If you've noticed some lamps get brighter the same time some others dim it could be a high resistance neutral so instead of having 120-0-120, when the load isn't balanced the split might be 150-0-90 when a appliance like a fridge puts a heavy load on one side.
The starting surge for a fridge is actually rather modest. However, an air conditioner can have a surge of 40 amps or more on an ordinary 110V, 15A circuit. Combine that with a bad neutral and things could get really bad, really fast!
Ed
-
Seems unlikely that one wouldn't notice that though. My grandma's house lost the neutral once after a lightning strike to the overhead line vaporized the neutral bus in the meter box. She had lights that were very dim and other lights very bright, with everything changing any time something was switched on or off. It was not subtle.
-
Try replacing the socket. I had one in my house that did that. It turned out to be the socket. (It probably wasn't burning the bulbs.)
Also, if the fan is unbalanced, it can cause bulbs to wear faster.
-
Seems unlikely that one wouldn't notice that though. My grandma's house lost the neutral once after a lightning strike to the overhead line vaporized the neutral bus in the meter box. She had lights that were very dim and other lights very bright, with everything changing any time something was switched on or off. It was not subtle.
Yes, if the neutral is gone, the results aren't subtle. But, as mentioned earlier, if the neutral is poor, you could get results just like the Mp3 is seeing.
Ed
-
A bad connection can cause this. It could be in the fixture, switch, or a junction in between.
-
How? Maybe with CFL or LED bulbs that have electronics in them, but incandescent bulbs don't mind rapid switching or voltage sags. If they're in a fan then it's almost certainly vibration.
-
A bad connection can cause this. It could be in the fixture, switch, or a junction in between.
I'll second this. The only time I've seen bulbs ping regularly was from corroded screw terminal connections in ceiling light cords. Rather than just break connection, it seemed to heat up causing the occasional flicker followed by a pop.