house voltage

[andrew]

Just curious as to how much your wall voltage can vary. Within 3 hours mine went from 129v to 114vt. Thanks

[alanp]

Sometimes it sounds as if Americans import electricity from the Mongolian steppes.

Does European power fluctuate this much? Power here is typically pretty spot on 240V.

[selloutrr]

WOAH! 129V to 114V? are these peak reading or RMS? where do you live? it sounds like generator voltages. you should really get a Constant Voltage Transformer installed on your main power service.

my power flux's between 118-124 max before the CVT and a flat 120V after.

[passfan]

It all depends on where you are at on the grid and wether or not it's at peak demand. When everyone is turning on their stove to cook the voltage is going down. Voltage drop is measured as a percentage by the NEC and the allowable rate is 8%. Something else to consider is what is the measurement at the service, do you have a problem with flickering lights, do your lights dim when your AC clicks on? These are all signs of potential connection problems in your home or on the pole. You could also just be the last house on that particular string off the grid. If your home is older it may be time to tighten all the connections in the panel, they do work loose over a period of a few years and servicing every couple of years is a good idea for copper conductors and every year for aluminum.

[Phil_S]

Just curious as to how much your wall voltage can vary. Within 3 hours mine went from 129v to 114vt. Thanks

I've seen mine in the same approximate range. Mostly, though, it stays between about 119 and 124. I don't recall seeing a 15V swing in that short of a time. Then, again, I don't keep a meter in the wall socket!

I see you live in Alabama, where I imagine temperatures in the 90's are the norm this time of year. I can see where peak demand in the hottest part of the day could have a marked effect. I'm going to suggest this would be something you typically see in the summer rather than the winter. You think so?

[andrew]

Yes it is an older house but i haven't had any trouble with flickering or browning. I first checked it at about 6:30 PM and later around 9PM.I will keep the advise in mind.I had a hell of a time trying to tweak the power string with the fluctuation. I adjusted the voltages on a parallel power supply to a schematic while the house voltage was at 114v. If the house voltage goes up I'll use the VVR to bring the power supply down a bit. It makes me wonder how many amps are built during a high voltage period and used during a low voltage period. I recall where some guys carry around a variac to emulate the 60s voltage supply to their vintage Marshalls. ( Plexipalace) Thanks again all.

[wicker]

In Poland we use 230 , but I find that voltages are normally from 225-235, rather steady.

[Alexo]

I used to worry about this stuff, but I just don't think it's that big a deal anymore. The great thing about tubes (as opposed to say ...digital) is the wide tolerance. The electrolytics alone are often rated to a +/-20% tolerance, for god's sake, mallory signal caps are +/-10%. The resistors in the old days (before we started using Vishays) were at BEST within 10% tolerance and frequently much looser than that. I'm not saying an 8% difference in your voltages is negligible, I just don't think it's worth worrying about. Most of the tube technology we're using was made to survive WW2 bombing raids, for goodness sake.

[David Root]

Mine are pretty normal, 118 to 122, and mostly between 119 and 121. Irritating when measuring a circuit to get 120V base numbers but nothing to worry about in operation.

[Structo]

Where I live I have only noticed about a ~4-5v swing.

So I don't worry much about it at all.

[RevD]

Times I've measured here in Phoenix at home were usually around 122v. I suspect some clubs I've played that were pretty old were all over the map, one in particular almost gives you a brown sound on even a fairly clean amp. I've never checked at a gig, might be interesting to see some time how much variance we see at a gigging situation.

Regards,

Rev D.

[David Root]

Would that one be the Rhythm Room?

[PlinytheWelder]

Here in Florida I get about a 4 -5V swing, But the guy in AL could have been in a "BrownOut", where they cut the voltage due to huge demand. This can happen during really hot days...

[Cliff Schecht]

There are probably a dozen threads on this so I'll just bump one..

Just measured my wall voltage at 125.8V.. I don't want to test my new Rocket build because the Stancor PT I used is of course wound for 117V. I need to build a permanent bucking transformer box, preferably with an AC meter as well. Or a small variac would work too of course but my current variac isn't safe at all in the proximity of the unknowing. It has these really convenient banana jack ports coming out of the side for hot, cold and earth that will shock the piss out of you..

What do you guys usually do? I'm tired of tacking in resistors on the heaters to keep those voltages right while the B+ runs too high and alters the amps sound. A resistor in the primary is a no no and variacs aren't safe to have around drunken bandmates.. I'm thinking a permanent bucking transformer in a breakout box would be the safest solution.

[TheGimp]

Around here (NE TN) it varies a lot with location. Some homes are on common transformers and if multiple heat pumps kick in at once during peak demand, voltage can really drop.

I'm the only house on a transformer, off a main three phase line. My voltage is pretty stable and varies from 122 to 128VAC rms.

With the heatpump off I just measured 126.3Vrms in the shop. I flipped on a 1.6KW electric heater on the same circuit and it dropped to 123.6Vrms.