I need a mains voltage tracking circuit
idbruce
Posts: 6,197
Hello Everyone
I want to create a Propeller based monitoring device for tracking the voltage coming into a 120/240V 200A main breaker. I keep getting intermittent voltage on one of the 120V lines (or at least I believe it is a line instead of a neutral) coming into the home and I believe it is on the service side of the panel. The house lights keep dimming or flickering, and I know it is not good. I believe it is on the service side of the panel, because the problem gets worse when the winds pick up. The utility company has been out a couple of times, during which time they replaced the connectors at the masthead, and inspected the connection where the service run connects to their main lines (in my opinion, they should have redone those connections). While they were here and the meter was removed, I tightened all lugs within the meter socket, tightened the lugs on the main breaker, tightened all lugs on the inividual breakers, tightened all lugs for the neutrals and grounds. Between my work and their work, the problem still remains.
There is also another reason I believe it is on the service side of the panel, which is, the problem occurs in various parts of the home which are definitely on different branch circuits and breakers. Of course you could say that it could be a loose shared neutral, and I agree that it could be, but I recently remodeled a room and installed all new wiring that went straight to a breaker in the panel. This remodeled has the same problem of dimming and flickering lights. So now you are thinking the problem is faulty wiring or it is at the panel. As I previously said, I tightened everything in the panel, and as an electrician, I take pride in making very good splices and connections.
The utility company says that the problem must be in the house. I say they are wrong and I want to prove it. Do you have any ideas for a voltage monitoring device made from a Propeller?
Bruce
I want to create a Propeller based monitoring device for tracking the voltage coming into a 120/240V 200A main breaker. I keep getting intermittent voltage on one of the 120V lines (or at least I believe it is a line instead of a neutral) coming into the home and I believe it is on the service side of the panel. The house lights keep dimming or flickering, and I know it is not good. I believe it is on the service side of the panel, because the problem gets worse when the winds pick up. The utility company has been out a couple of times, during which time they replaced the connectors at the masthead, and inspected the connection where the service run connects to their main lines (in my opinion, they should have redone those connections). While they were here and the meter was removed, I tightened all lugs within the meter socket, tightened the lugs on the main breaker, tightened all lugs on the inividual breakers, tightened all lugs for the neutrals and grounds. Between my work and their work, the problem still remains.
There is also another reason I believe it is on the service side of the panel, which is, the problem occurs in various parts of the home which are definitely on different branch circuits and breakers. Of course you could say that it could be a loose shared neutral, and I agree that it could be, but I recently remodeled a room and installed all new wiring that went straight to a breaker in the panel. This remodeled has the same problem of dimming and flickering lights. So now you are thinking the problem is faulty wiring or it is at the panel. As I previously said, I tightened everything in the panel, and as an electrician, I take pride in making very good splices and connections.
The utility company says that the problem must be in the house. I say they are wrong and I want to prove it. Do you have any ideas for a voltage monitoring device made from a Propeller?
Bruce
Comments
Simplest demonstration to prove to a utility, will be an extension chord run over the fence, and two light-bulbs.
Connect your local power sample light bulb, to close to the main feed-in.
Such power-interrupting connections usually generate significant RFI, so you could also get a portable radio, and see if that can give a clue to the location ?
Nice and interesting
two 110/6V transformers fed into a full wave rectifier bridge and monitored by a 12 bit multichannel ADC would probably do the trick. Record the results onto an SD card and drop it into spread sheet showing date, time and voltage of each leg. Be sure and use a very stable reference for the ADC.
Jim
Another interesting idea. I could even use that circuit for powering the propeller
The 6V transformer is a good idea but you don't want to use it to power anything with fluctuating current draw. That will affect your readings. Use a separate power supply for the monitoring circuitry and two transformers with fixed resistors as loads for each side of the 220VAC line. A battery backup circuit for the monitoring circuit would also be a good idea.
I'd like to build one but that's a bit out of my league.
Rent or borrow a BMI line meter, attach it to the input of the main breaker and let it spew paper or log for a week. Then you will have all you need to prove one way or another that the problem is on the power companies service or not. The voltage should be stable at the service input unless there is a problem upstream such as a bad connection to the distribution from the house to the common cable to the transformer, transformer connections, or another user with problems serious enough to cause significant loading on the distribution line to reduce the voltage at your service entrance. You have NO aluminum wiring I hope??
Frank
Jim has the right idea with two 110/6V transformers and I will put in a little twist in his idea.
Instead of just using a 12 bit multichannel ADC chip for the conversions for the Propeller. Try using a Analog Optoisolator just after the full wave rectifier bridge.
The Analog Optoisolator are designed to separate two different analog voltages. Analog Optoisolator has a LED side to look at the voltage drop and a resistor side of the Analog Optoisolator would than connect up to the Propeller or to the a 12 bit multichannel ADC chip.
While, I was typing my last post, you stated this. Most homes today have aluminum wire feeding from the main breaker to the power company's meter and copper wire is used for the branch circuit breakers which feed the lights and receptacles. I can't remember in my 23 years of being electrician and the first 3 years was wiring homes. Electrical contractors doing homes don't use anything other than aluminum for services. Aluminum wire is cheaper to buy then copper wire and the power companies use aluminum wire form the house to the pole.
Referring to internal wiring, from panel inward. I would assume that the power company connections are the appropriate materials for the wiring used. But I remember the late 70s and early 80s fires from mismatched wire/connections inside the homes.
Frank
Wow, this thread has more activity than I thought it would receive.
@kwinn - I agree. I was to quick to respond and that was a definite oversight.
@Jorge P - A thermal imager would be nice to help find the problem if the problem was on the house side of the service, but it's not
@frank freedman - All copper THHN wire, right upto the mast head.
@bsnut - Hmmmm.... That is debateable..... A large portion of my electrical career was spent wiring homes. I would say it all depends on the locality. In the midwest, it seems to be mostly copper upto the mast head. When you get to the southwest, it appears to be aluminum. However, the commecial guys use a lot of aluminum service wire, as I am sure this is the case for industrial also.
I had this exact problem when I bought my house. The lights in one set of rooms would flicker during storms, to the point my computer would reboot. The neighbors said the previous owner died in the house and his ghost was trying to scare us out. Went up in the attic on a dark and stormy night to kick the ectoplasm out of him, but no ghost. The local electrician came out and replaced the 25 year old breaker box and all the breakers. Next time a storm came, the lights in the office flickered as usual. I called the electrician up to scream at him, he said "the connections on the pole are loose, and the utility company will come and re-crimp them for free". I resisted the urge to pop his head off like a dandelion, and called the utility. They re-did the wires on the pole, and the problem is gone.
Only one answer to that one....DDDDDDDDDDDDDOOOOOOOOOOOOOOOOOOOOOOOOOHHHHHHHHHHHHHHHHHHHHHHHHHHHH!!!!!!!!!!! but maybe the box needed to go anyway.....
Are you still thinking about doing this project anyway? If, so here is the link for the datasheet for the Analog Optoisolator
http://www.datasheetcatalog.org/datasheet/perkinelmer/VT500.pdf
The Analog Optoisolators are page 48 of this pdf.
After reading one of my previous posts, I realize it could have stated my opinion a little more clearly. Most homes that I have worked on, or have had the opportunity to examine the wiring, have mostly been wired with copper conductors. Occassionally you will find a home that has been wired with aluminum conductors, but not to often. However, as for service wires, especially from the main breaker to the mast head, electrical contractors in the southwest will often use aluminum wires in an attempt to save money.
I have to do something.
If the problem is on the house side, then I need to find and fix the problem.
If the problem is on the utility side, then the utility company needs to find and fix the problem.
Bruce