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Tech: Power breakers/voltage-affecting instruments

Tattie Bogle 03 Sep 16 - 04:29 PM
Newport Boy 03 Sep 16 - 05:50 PM
GUEST,Phil d'Conch 03 Sep 16 - 06:36 PM
Jack Campin 03 Sep 16 - 06:55 PM
Joe Offer 04 Sep 16 - 02:04 AM
Newport Boy 04 Sep 16 - 03:58 AM
Tattie Bogle 04 Sep 16 - 04:36 AM
BobL 04 Sep 16 - 05:32 AM
Tattie Bogle 04 Sep 16 - 07:27 PM
GUEST,.gargoyle 04 Sep 16 - 09:36 PM
punkfolkrocker 04 Sep 16 - 11:19 PM
GUEST,Et Clamor 04 Sep 16 - 11:51 PM
GUEST,Phil d'Conch 05 Sep 16 - 01:33 AM
BobL 05 Sep 16 - 02:51 AM
punkfolkrocker 05 Sep 16 - 06:40 AM
Tattie Bogle 11 Sep 16 - 09:17 PM
GUEST,ripov 12 Sep 16 - 04:04 PM
GUEST,ripov 12 Sep 16 - 04:09 PM
Jack Campin 12 Sep 16 - 07:23 PM
Tattie Bogle 13 Sep 16 - 07:20 PM
Mr Red 14 Sep 16 - 02:24 PM
GUEST,ripov 14 Sep 16 - 06:21 PM
Mr Red 15 Sep 16 - 04:02 AM
GUEST,watcher 15 Sep 16 - 01:38 PM
Jack Campin 15 Sep 16 - 01:58 PM
Tattie Bogle 16 Sep 16 - 04:25 AM
selby 16 Sep 16 - 04:36 AM
Jack Campin 16 Sep 16 - 09:10 AM
GUEST 16 Sep 16 - 11:11 AM
GUEST 16 Sep 16 - 11:30 AM
selby 19 Sep 16 - 11:59 AM
Jack Campin 19 Sep 16 - 12:23 PM
punkfolkrocker 19 Sep 16 - 12:29 PM
selby 19 Sep 16 - 02:57 PM
GUEST,ripov 19 Sep 16 - 04:36 PM
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Subject: Tech: Power breakers and voltage
From: Tattie Bogle
Date: 03 Sep 16 - 04:29 PM

At a recent gig (UK) I discovered that all of the power sockets in the village hall where we were to play had been replaced since last year with new ones which had integrated power breakers in them: presumably installed for safety reasons. No "normal"/standard wall sockets at all.
No problems with our PA or plug-in guitars, but a horribly flat digital piano for me! Somewhere between a semi-tone and whole tone down, so a simple semi-tone transpose would not cure it. I have had this happen very occasionally before, and usually switching off and switching on again cures it: but not this time! After 7 or 8 reboots, just as flat as ever, so out with the handbook, and remind myself how to do a "fine tune" - fortunately my piano has this facility, or it could have been disastrous!
On checking the piano at home and playing again since via a more standard 3-pin socket, no problem at all, so I conclude that the power-breaker socket somehow reduced voltage to the piano, causing a malfunction. Anyone else experienced similar?

Previous problem when linked to generator power, but it turned out that the generator was only achieving barely 200v, well short of our usual 240.


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Subject: RE: Tech: Power breakers and voltage
From: Newport Boy
Date: 03 Sep 16 - 05:50 PM

Very unlikely to be a reduction in voltage by the socket. Modern RCDs check for tiny differences in current between the pins and trip if it more than about 30mA. They have almost zero resistance, so can't reduce the voltage. More likely to be a poor contact, but that would cause the socklet or plug to overheat.

If you play there again, take a meter to check the voltage.

Phil


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Subject: RE: Tech: Power breakers and voltage
From: GUEST,Phil d'Conch
Date: 03 Sep 16 - 06:36 PM

Tuning & timing problems are usually frequency, not current or voltage. I've had problems with digital load centers before and it almost always came down to:

A: An Ethernet back end similar to D-Link monitoring the outlets and reporting faults to the main panel or…

B: A noisy; switching or poorly isolated (common mode) power supply somewhere in the panel or load.

In both cases it showed up as AC noise superimposed on the line frequency and could be seen on an o-scope.

A lot of (most?) generators do not produced a pure synewave AC output. It's square, stepped or modified. They can also give line freq based clocks a problems. It's one of the things the better UPS and inverter systems are designed to prevent.

Phil-deux


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Subject: RE: Tech: Power breakers and voltage
From: Jack Campin
Date: 03 Sep 16 - 06:55 PM

I would suspect something is reducing the voltage before it ever gets to the socket - maybe the village hall is a long way from the substation, or new housing has been built in between and is siphoning the power off first?

If you ever play at Newbattle Abbey, expect the opposite problem - it's very close to the substation and gets cask-strength electricity, the absolute upper limit of acceptable voltage variation.


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Subject: RE: Tech: Power breakers/voltage-affecting instruments
From: Joe Offer
Date: 04 Sep 16 - 02:04 AM

For those who, like me, wondered: an RCD is a Residual Current Device is what we call a GFI (ground-fault interruptor) in the States.

-Joe-


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Subject: RE: Tech: Power breakers/voltage-affecting instruments
From: Newport Boy
Date: 04 Sep 16 - 03:58 AM

Thanks, Joe - I forget that terms vary. These things are amazingly sensitive. Some years ago, I was installing some new ceiling roses in the house. I had switched off the lighting circuit breaker at the board and was working with a lead light from the power circuit. The circuit breakers isolate the live feed only.

I had stripped the new wires and was using both hands to feed them tidily into the connection strip, when BANG!. No light! I went to the board and found the main RCD had tripped - I had no idea why. I closed it and went back to work, only to have the same thing happen 5 minutes later. I closed the RCD again and used my meter to check all the wires I was working on - zero volts.

This time, I summoned assistance and, with someone at the board, systematically tested the various wires with my hands, tripping out now and again. Turned out that holding the neutral and earth wires between my finger and thumb would trip the RCD every time. On our supply, there is theoretically no voltage difference between neutral and earth.

It took two weeks of investigation to find an old lighting switch cable buried direct in the plaster in the oldest part of the house. At some time n the past, a nail had been driven through the cable and the wires were in contact with the plaster. This hadn't tripped the new RCD because we never used the switch to which it led.

Phil


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Subject: RE: Tech: Power breakers/voltage-affecting instruments
From: Tattie Bogle
Date: 04 Sep 16 - 04:36 AM

Thanks for all the suggestions. No problems in same hall last year before they changed all the wall sockets to these new-fangled ones with RCDs, and no new building since last year.
I have passed comment to the friend who invited us to play, and she will get their electrician to check.


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Subject: RE: Tech: Power breakers/voltage-affecting instruments
From: BobL
Date: 04 Sep 16 - 05:32 AM

I suspect the RCDs are a red herring.

(Dons computer engineer hat) Early Hammond organs using tonewheels driven by a synchronous motor were susceptible to changes in mains frequency, which could be a problem on a festival site relying on generator power. However, modern electronic keyboards get their pitch from a crystal oscillator, which is utterly stable - think quartz crystal clocks. They are also quite tolerant to mains voltage drop: as Jack suggested, if this was the problem it is likely to have affected the entire hall.

On your return home, did you have to reset the tuning to its normal setting?


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Subject: RE: Tech: Power breakers/voltage-affecting instruments
From: Tattie Bogle
Date: 04 Sep 16 - 07:27 PM

No: spot on as soon as I switched on: and in practice later that week.


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Subject: RE: Tech: Power breakers/voltage-affecting instruments
From: GUEST,.gargoyle
Date: 04 Sep 16 - 09:36 PM

WHY Even Fret???

YOU have it consistant and adjust in the studio???

Sincerely,
Gargoyle


For each instrument, and each amp, and each speaker there is a rating....always stay 50% under and you will have "no geief".

(Blowing a speakerv by is pure bowing down to an idiiot.

HI


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Subject: RE: Tech: Power breakers/voltage-affecting instruments
From: punkfolkrocker
Date: 04 Sep 16 - 11:19 PM

This never happened in the old days when amplified instruments were powered by either wind or coal fired steam..

No wonder most old folkies hate electricity so much... ⚡ 😜


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Subject: RE: Tech: Power breakers/voltage-affecting instruments
From: GUEST,Et Clamor
Date: 04 Sep 16 - 11:51 PM

Steampunkfolkrocker


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Subject: RE: Tech: Power breakers/voltage-affecting instruments
From: GUEST,Phil d'Conch
Date: 05 Sep 16 - 01:33 AM

PFR: This never happened in the old days when...

Obviously you never saw my Aunt Wautheena on the pyrophone.


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Subject: RE: Tech: Power breakers/voltage-affecting instruments
From: BobL
Date: 05 Sep 16 - 02:51 AM

On the contrary PFR. The old calliope (steam-blown organ) was wickedly out of tune on frosty mornings, at least until the pipes got up to working temperature.


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Subject: RE: Tech: Power breakers/voltage-affecting instruments
From: punkfolkrocker
Date: 05 Sep 16 - 06:40 AM

errrmmmm.. I hesitate to mention the greek / roman water organ
out of sympathy for the cranky ancient plumbing of most older male mudcatters bladders...

.. who are also powered & driven by fluids and wind in the mornings.... 😘




OK.. I know I am prone to taking the piss out of the dominant antipathy towards electric guitars, keyboards, and amps
but I've just actually purchased my first acoustic guitar in at least a decade....
[for context, I've aquired 9 or 10 electric guitars and another valve amp since xmas....]


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Subject: RE: Tech: Power breakers/voltage-affecting instruments
From: Tattie Bogle
Date: 11 Sep 16 - 09:17 PM

Call me thick if you like, but I don't understand Gargoyle's comment! I don't have a studio. I play in a band, which includes other fixed pitch instruments which can't simply re-tune to suit me! I have to be in tune with THEM! So, thank goodness for the fine tune facility on my keyboard on that occasion or I'd have been up sh#t creek without a paddle!


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Subject: RE: Tech: Power breakers/voltage-affecting instruments
From: GUEST,ripov
Date: 12 Sep 16 - 04:04 PM

Since guitars neeed to be tuned before they're played, following on from Tattie Bogles post, why didn't the guitarists just tune to your piano, just as an entire orchestra tunes to a piano if they're doing a piano concerto (yes I know they tune to the oboe, but that is initially tuned to the piano in these circumstances).


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Subject: RE: Tech: Power breakers/voltage-affecting instruments
From: GUEST,ripov
Date: 12 Sep 16 - 04:09 PM

....But as to your piano going out of tune, that is weird. And must have been extraordinarily aggravating!


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Subject: RE: Tech: Power breakers/voltage-affecting instruments
From: Jack Campin
Date: 12 Sep 16 - 07:23 PM

Tattie Bogle doubles on the melodeon. Good luck tuning that...


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Subject: RE: Tech: Power breakers/voltage-affecting instruments
From: Tattie Bogle
Date: 13 Sep 16 - 07:20 PM

And we have a piano accordion in the band: screwdriver anyone?


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Subject: RE: Tech: Power breakers/voltage-affecting instruments
From: Mr Red
Date: 14 Sep 16 - 02:24 PM

I tried to post but it looks to be not here. I was suggesting that if the piano had an external plug/power pack thingy that the problem was in that being an unregulated power supply. The same could be true of internal power supplies, it is all about quality of design.

But if the tuning did not alter on return to a good mains voltage then the above theory is redundant. Even 20 year old pianos I would expect the pitch to be related to the CPU crystal.

That leaves only something along the lines of some inadvertent movement of the pitch control as the piano is maneuvered. It would have to be on, and the knob/buttons near the hand doing the handling. Or there is some obscure bug in the software, which is not going to be solved.


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Subject: RE: Tech: Power breakers/voltage-affecting instruments
From: GUEST,ripov
Date: 14 Sep 16 - 06:21 PM

Alright then, the lucky guitarists have the choice of 3 A's before they even switch their tuners on!


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Subject: RE: Tech: Power breakers/voltage-affecting instruments
From: Mr Red
Date: 15 Sep 16 - 04:02 AM

Hey Tattie - you think you have problems. Pity the poor bodhran player, not only does he have humidity to contend with, but there is this work function thingy going on. The skin dries out as it is played. And that is before the musos trot out all the Bodhran jokes.


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Subject: RE: Tech: Power breakers/voltage-affecting instruments
From: GUEST,watcher
Date: 15 Sep 16 - 01:38 PM

I've seen adverts for equipment that claims to save fuel bills (and the environment!) by significantly reducing the voltage. Could it be that the hall has fitted these devices, and they, not the circuit breakers, are causing the problem with your keyboard?


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Subject: RE: Tech: Power breakers/voltage-affecting instruments
From: Jack Campin
Date: 15 Sep 16 - 01:58 PM

Hey Tattie - you think you have problems. Pity the poor bodhran player [...]

There's something Tattie isn't admitting to.


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Subject: RE: Tech: Power breakers/voltage-affecting instruments
From: Tattie Bogle
Date: 16 Sep 16 - 04:25 AM

Interesting suggestion, Watcher! Will ask!
And Jack is continuing to blow my cover: yes, I play bodhran too, as well as button accordion, and piano - but not all at once!


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Subject: RE: Tech: Power breakers/voltage-affecting instruments
From: selby
Date: 16 Sep 16 - 04:36 AM

The power industry has been struggling lately due to the unseasonal hot weather and air con. The power plants try to work out when is the best time to do essential maintenance with the smallest loss in profits . September has back fired on them and high prices have been paid by the grid for electric , obviously the grid does not like high prices and frequency control is used to aliviate problems I would suggest the frequency was down on the night of your gig and no other problem exists.
Keith


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Subject: RE: Tech: Power breakers/voltage-affecting instruments
From: Jack Campin
Date: 16 Sep 16 - 09:10 AM

Reducing voltage is possible, reducing frequency isn't - power transmission equipment is tuned to the standard mains frequency and if you try to put a current through it at a significantly different frequency you will get enormous losses and transformers will explode.


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Subject: RE: Tech: Power breakers/voltage-affecting instruments
From: GUEST
Date: 16 Sep 16 - 11:11 AM

(http://www2.nationalgrid.com/uk/services/balancing-services/frequency-response/)
"System frequency is a continuously changing variable that is determined and controlled by the second-by-second (real time) balance between system demand and total generation. If demand is greater than generation, the frequency falls while if generation is greater than demand, the frequency rises."

However, it has to be within "±1% of nominal system frequency (50.00Hz) save in abnormal or exceptional circumstances."


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Subject: RE: Tech: Power breakers/voltage-affecting instruments
From: GUEST
Date: 16 Sep 16 - 11:30 AM

I can't find a snappy quote for voltage but in the UK it has to be 230 with a tolerance levels of -6% to +10%. (so 216 to 253 volts)

It is generally in the interests of power companies to keep it up because they sell more power. I guess that if, as Selby implies, they have cocked up their deals and it is costing more than they are charging then they might prefer to let it fall.

Though the market works second by second, so I guess it's not that simple.


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Subject: RE: Tech: Power breakers/voltage-affecting instruments
From: selby
Date: 19 Sep 16 - 11:59 AM

Frequency varies greatly if anyone has noticed electric clocks speed up and slow down. Exceptional circumstances could be a NISIM.
I am sorry my 40 years in the power industry was wasted
Keith


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Subject: RE: Tech: Power breakers/voltage-affecting instruments
From: Jack Campin
Date: 19 Sep 16 - 12:23 PM

A power utility will not reduce the power it delivers by changing frequency. This explains what you can get away with using the decades-old technology the power grid is made of - i.e. not very much:

http://www.edn.com/design/components-and-packaging/4369085/Using-a-power-transformer-at-a-frequency-it-wasn-t-designed-for

(executive summary: any significant change and BANG!)

But reducing voltage is effective, safe, feasible and often done.


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Subject: RE: Tech: Power breakers/voltage-affecting instruments
From: punkfolkrocker
Date: 19 Sep 16 - 12:29 PM

Deliberately reducing voltage to classic circuit fuzz boxes is an age old method for modifying / improving the character of the resulting guitar tone....


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Subject: RE: Tech: Power breakers/voltage-affecting instruments
From: selby
Date: 19 Sep 16 - 02:57 PM

I bow out to such a knowledgable man as yourself Jack you are really sooooo clever
Keith


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Subject: RE: Tech: Power breakers/voltage-affecting instruments
From: GUEST,ripov
Date: 19 Sep 16 - 04:36 PM

In some cases interrupting the amplifier supply is even better!


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