Thanks for the great advice 
It's the SP8 and I am only guessing that the amp is going unstable, BUT it seems consistent.
I spoke to UK Power Networks, they will send someone around to look at it, in the meantime I will try and do some more checks on what is measuring where.
Curiously after my call last night the power is a nice flat 240V and the amp works as it should.......
I should have built a new preamp from scratch would have been easier!!......or maybe not
It's the SP8 and I am only guessing that the amp is going unstable, BUT it seems consistent.
I spoke to UK Power Networks, they will send someone around to look at it, in the meantime I will try and do some more checks on what is measuring where.
Curiously after my call last night the power is a nice flat 240V and the amp works as it should.......
I should have built a new preamp from scratch would have been easier!!......or maybe not
They said they would come round in the next few days.....nothing yet.
so far low voltage not returned when I have tested, or no amp instability yet....
Local step-down transformers in electrical utility supplies have the ability to change the low side voltage to maintain a nominal voltage at the consumers premises .
Voltage fluctuation can be due to high load current on that particular spur .
They are equipped with voltage tapping regulators which can be changed under no load conditions --OR-- be under load types allowing change under normal working conditions .
Under load types can be changed can have the tappings changed --Automatically .
Hence --as I said previously no visit required to customer.
Voltage fluctuation can be due to high load current on that particular spur .
They are equipped with voltage tapping regulators which can be changed under no load conditions --OR-- be under load types allowing change under normal working conditions .
Under load types can be changed can have the tappings changed --Automatically .
Hence --as I said previously no visit required to customer.
If you have an electric shower then take a note of the voltage with the shower on and off. Typically these will pull anywhere from 7.5 to 9.5kWh.
You can use lesser loads such as a 3kWh immersion or fire but the change will be less. It should be easy to see how well the supply holds up in your property.
In fact for curiosity I'll try that now myself.
You can use lesser loads such as a 3kWh immersion or fire but the change will be less. It should be easy to see how well the supply holds up in your property.
In fact for curiosity I'll try that now myself.
As I said it could be in your house but more likely at the sub. Tap changers are normally on the 11KV primary side of the transformer. The fluctuations indicate a fault such as a corroded or loose connection on the secondary 415/230V high current side.
Larger transformers do have automatic voltage regulation but if that was the case to fluctuate the way you described it would be way out and would be sorted sharpish. There was a case in Swindon where a certain bunch of folks stole the regulation equipment and it caused high voltages for customers and in some cases fires.
As Mooly says. Measure your voltage without too much load on then switch on some big loads. Electric shower, emersion heater, kettle etc. and measure again.
Cheers
Matt.
Larger transformers do have automatic voltage regulation but if that was the case to fluctuate the way you described it would be way out and would be sorted sharpish. There was a case in Swindon where a certain bunch of folks stole the regulation equipment and it caused high voltages for customers and in some cases fires.
As Mooly says. Measure your voltage without too much load on then switch on some big loads. Electric shower, emersion heater, kettle etc. and measure again.
Cheers
Matt.
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Ok - will I have a very large commercial espresso machine that takes an enormous current, had to have it's own spur so let's see what that does......
like this.
Mains into RHS - into splitter/junction and then 2x consumer units for the house, and then also into the switch on the LHS which feeds a 100A or similar armoured cable to a consumer unit that is hidden behind the wall in the music room (in adjoining room cupboard).
Hope this makes sense?
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Hi Tonescout, merry Christmas
A nice clean installation, did you take any readings with and without a large load on like your coffee machine?
As you have two boards is the low voltage present on circuits in both boards,?
Being a relatively new installation, 2016 from the inspection sticker. It could well be a loose connection in one of the boards. If you are still able to contact the electrician's that installed it I would ask them to take a look.
Cheers
Matt.
A nice clean installation, did you take any readings with and without a large load on like your coffee machine?
As you have two boards is the low voltage present on circuits in both boards,?
Being a relatively new installation, 2016 from the inspection sticker. It could well be a loose connection in one of the boards. If you are still able to contact the electrician's that installed it I would ask them to take a look.
Cheers
Matt.
Well not yet with the large coffee machine load, but I have measured the voltage at the incoming meter (this is on an armoured cable from there in the RHS switch about 15m away) and upstairs and downstairs, and on the hifi CU and they seem pretty close. Bear in mind that I can measure the voltage and see if change from like 215 to 229 in a few minutes, so it's kind of difficult to be sure of any comparison - I need 222 or so or my amp is unstable.....and unusable :-(
nothing - just promised to send someone around, but it is Christmas and lockdown so I didn't expect rapid service ///
I tried it just now and it's 235, it's all over the place --> is that normal it changes so much all the time?
It shouldn't be up and down like a yoyo but it certainly wont be a constant. You might see discrete step changes of a few volts but it shouldn't be more than that and it should shouldn't be going from the bottom of the allowable range to the top in jumps.
Have you not got an electric shower or immersion that you can just put on and see how it affects the voltage?
If you had a bad connection in the property then at high load currents (do you ever draw high load currents) you would be getting heat and lots of it from the bad joint and that would be very unusual (and very dangerous).
Have you not got an electric shower or immersion that you can just put on and see how it affects the voltage?
If you had a bad connection in the property then at high load currents (do you ever draw high load currents
) you would be getting heat and lots of it from the bad joint and that would be very unusual (and very dangerous).
I will have a look tomorrow putting the coffee machine on. I have gas and wood fired heating, and showers are mains pressure through a thermal store, so no electricity here. underfloor heating through an electric pumped water from thermal store system, so that can't be much either
dishwasher, washing machine and induction hob and electric ovens are the only real quantity users I would think.
My instinct is the supply into the property but hey what do I know!
dishwasher, washing machine and induction hob and electric ovens are the only real quantity users I would think.
My instinct is the supply into the property but hey what do I know!
Knowing the UK mains electricity from 100,s of complaints from the public on my old website , its normal during high consumption for the voltage rate to drop but yours is the worst I have come across apart from---no service-- in the whole of the UK.
The really angry people had neighbours /factories using welding gear which caused very high fluctuation and massive spikes --after getting advice from the websites legal department ( not free ) engineers transferred them at the stepdown transformer which in each case cured the fault .
Nobody but nobody had your--215 volt level which --in my book --is a disgrace .
If they cant supply a workable mains voltage then all this talk of electric vehicle charging goes out the window --IMO.
As a practical down to earth person action speaks louder than words .
The really angry people had neighbours /factories using welding gear which caused very high fluctuation and massive spikes --after getting advice from the websites legal department ( not free ) engineers transferred them at the stepdown transformer which in each case cured the fault .
Nobody but nobody had your--215 volt level which --in my book --is a disgrace .
If they cant supply a workable mains voltage then all this talk of electric vehicle charging goes out the window --IMO.
As a practical down to earth person action speaks louder than words .
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