power frequency

[Cybrvanr]

As just about all of you may know, power is supposed to be 60 cyles at 120 volts here in America. The problem is, what do you do if it isn't? I have several electric clocks in vintage appliances and on the walls, and I have noticed an interesting phoenominon. They are all loosing about the same amount of time. It's not much...about 5 minutes per day. I could figure 1 clock being off due to mechanical issues, but ALL of them? and the same amount? The only thing I can think of is that the power frequency is off!

The other thing that clued me into this is my Hammond organ that is just the ever so slightest bit off key on the higher notes. These Organs have a synchronous motor in them that spins a tone generator. In effect, they cannot go out of tune, since the motor spins at the power frequency. The tone generator is basically a shaft with notched wheels along it, and magnetic pickups beside each wheel. As the wheels turn, they generate the different musical notes the organ can create. Curious about this power thing, I decided to measure some of the musical notes. I found "middle C" to be 438 hz (supposed to be 440 Hz) The error gets worse as the notes get higher in frequency, and is barely audible when played by itself. If you play it against a newer digital keyboard though, it's readily apparent!

The power company will probably think I'm high on some sort of drug telling them that their frequency is off, but probably nobody has ever questioned it before! It would be nice not to need to keep setting my clocks all the time though. I could figure on the voltage being off, but I would think a frequency error would be something that would be an issue all the way back to the generation plant!

 

[bethann]

Steven

Your right about the power company! We have had issues with them already. I really don't think they care about regulating anything. As long as you are between the lines of what they call normal, it's your baby after that. Have you looked at Furman power conditioners? At least for the Hammond! Is it a B3? The Furman AR1215 might work. Check out their site I'm sure it would be much more informative than me. As far as your house, maybe you could put a conditioner on the lines with the vintage stuff. To do the whole house at the main would cost you an arm and a leg!

 

[cadman]

This is interesting because by regulation, the frequency is limited in how far it can deviate from 60Hz. I've got a Nixie clock I built that relies on the 60cps as the time reference but since I don't show seconds I've never noticed the fluctuation. Fellow Nixians have noted a several second slow down during heavy load periods but the lines are adjusted during light periods to "catch up" so the net is zero.

If you're having to adjust your clocks to make up the difference then something is wrong! I'd call them on it!

Check out the link, it discusses the situation in western US and how the states are tied together.

Cory

http://www.utahpower.net/File/File22471.pdf

 

[tolivac]

I have a freind that lives in Richmond Va and they seem to have their share of power company problems.He has noticed the same sort of thing-the power there has some sort of frequency stability problems-have you tried to measure the frequency of your lines directly-Use a stepdown transformer between your outlet and your frequency counter or meter.Then watch it for a period of time and see how your line frequency drifts-sounds like its drifting downward in your case.Thats interesting observations with your Hammond Organ.a small filament transformer is good for providing a line sample for your meter or other tests.The low votage from it is not a shock hazard nor will it damage test gear like measuring right off the line could.If you have as oscilloscope you may want to look at the line sample with it to see if there are any harmonics riding on the line.Another question- does the problem get better or worse at night?when the line is lightly loaded.It does sound like you may have to call your power company on this. The frequency readings could help.also how is your line voltage-if it is too low-syncronous motors can drop out of sync.Radio Shack used to sell plug in line voltmeters.electronics suppliers may have them.

 

[kenmore1978]

Neat device

I have one of these devices, very useful and fairly cheap

http://www.the-gadgeteer.com/killawatt-review.html

 

[Cybrvanr]

One of the things I remember hearing on the news lately is that the extra cold weather is causing record power consumption in the area. I bet VA power is having a hard time keeping the frequency up with everybody's heat pumps checking out in the 20 degree and below weather. We're no stranger to power problems around here. Short term outages are a fact of life around here, even during times of good weather. I've measured the voltage can vary as much as 10 volts at times. UPS's are good for tweaking up those voltage problems, but they don'd do much for frequency problems...especially as subtle as it is.

My Hammond is a BC-V Bethann. It's the predecessor to the famous B3. It's built in the same cabinet as a B3 and looks basically identical. For the choirs effect, it has a second tone generator in it instead of the delay system like the B3 uses....makes for a more interesting effect. The vibrato system is pretty much the same. The instrument though doesn't have the neat percussive effect (heard in Deep Purple's song "Child in Time"). It's a VERY old instrument too. It is labled with "The Hammond Clock Company" so, I know it's age is prior to 1938, because that's when they started being known as the "Hammond Organ Company". BTW, I have also collected two neat art-deco style Hammond clocks!

 

[tolivac]

The man I know who lives in Richmond has two generators and has to use them frequently.He even wired a transfer switch system in his house.He runs the higher draw devices on one gen and small draw devices on another.He had to use the generators for over a week during one of the hurricanes-can't remember which one.
I like that "Kill-a Watt" analyzer--perfect for folks with power problems.Works sort of like a Dranetz analyzer-but much less expensive and more portable.The Dranetz device needs sampling transformers and the "Kill-A Watt" meter doesn't. Pretty neat.Where do you get them?
One of our transmitter plants runs on Dominion power and has to go on load managment a couple times a week-we have to do some of their programs becuase of the peak shaving.The plant I work at runs on a different power company.

 

[kenmore1978]

Kill-A-Watt device availability

I put Kill-A-Watt in a search and a lot of places came up where it can be purchased.

 

[kenmore1978]

Voltage variation

Actually, 10 volts is well within the "normal" range of voltage variation. Electrical devices are typically designed for a 10% tolerance of the voltage on the rating plate. 120 volts is the "nominal" voltage, but it can actually vary anywhere from 105 to 130 volts and still be within tolerance by the utility.