Are Over Voltage Problems widespread

[matthunt]

Are any of you seeing High voltage problems in houses with Solar/PV installed in same street?

I attended a call out a few weeks ago due to the fuse board apparently smoking. When i arrived it transpired it was the shower circuit, the voltage measured was 246v and the current 36 amps meaning a 7.5kw shower drawing 8.8kw through a cartridge type Wylex db. The fuse was rated at 30amps and you just could not touch it due to the heat. We all know of the inherant problems with this type of fuse whilst continuing to operate on steady over current. Has anyone else seen this type of problem? as i am aware that multiple PV installs in a street on the same phase will obviously boost the voltage due to the nature of the invertors.

 

[LlandrilloSpark]

Was it a rural location??
I know an SP guy who works the 11kv grids/subs, he says the distance between the substations is longer in some rural areas and the
Windings on the transformers are deliberately set so single phase voltages can be near 250v, to avoid volt drop, if you live next door to one in a rural area you could get near 250, my post in the ES candle lamp thread was an example of this, rural location ,246v measured I think and 220-230v lamps of the market blowing

 

[Knobhead]

I give up.

Noddy's "Beginners Guide to Elementary Electrical Calculus" is not in touch with reality.

 

[matthunt]

Tony, please try and keep the thread to a constructive level with informed and educated replies, i would not dream of stating you had a single braincell!, i realise the DNOs dont care about the supply voltage they supply us as in reality they make an extra 8% from us through the meter by supplying us at 240v

 

[LlandrilloSpark]

Directed at me tony?

 

[matthunt]

No Llandrillospark, i think it was me, but thats fine, i think he must of had a bad day

 

[LlandrilloSpark]

Just lately the Tin hats are out all over the place, it's like a war zone in here!

 

[matthunt]

hehe, dont worry maybe hes getting a book out to read!!

 

[MDJ]

Just lately the Tin hats are out all over the place, it's like a war zone in here!

:lol:
.

 

[worzol99]

Power companies keep supply voltages as high as possible to
minimize current in the supply network and hence delaying the need to make
improvements to the supply infrastructure to increase the current handling
capability. Makes sense so they dont have to spend there profits!

 

[MDJ]

Just lately the Tin hats are out all over the place, it's like a war zone in here!

this post is second only to Tony's upside down reply to a guy working in oz earlier, brilliant post, I'm still chuckling here, we need a funny post of the month award here, just brilliant haha

 

[plugsandsparks]

Certainly noticed voltage readings 250 and higher, never had 254+, times when i had 253 i did hang around to see if it would go even higher. Only call outs i have had that i can definetly attribute to sustained high voltages, rather than spikes, is the rapid blowing of incandescent lamps.
If say a shower or oven was given too much volts i would expect the elements to fail rather than the supply. But if the supply was on the ragged edge of design and not in proper fettle, i suppose its possible that could fail before the element inside.

 

[matthunt]

Power companies keep supply voltages as high as possible to
minimize current in the supply network and hence delaying the need to make
improvements to the supply infrastructure to increase the current handling
capability. Makes sense so they dont have to spend there profits!

Good to know someone else knows whats really happening out there

 

[Knobhead]

Tony, please try and keep the thread to a constructive level with informed and educated replies, i would not dream of stating you had a single braincell!, i realise the DNOs dont care about the supply voltage they supply us as in reality they make an extra 8% from us through the meter by supplying us at 240v

Where prey did you get that gem of misinformation. You (well I do) pay for electricity by volume. I.E. KWHr

 

[Gavin A]

253-207v and 440-360v nowadays, anyway thats not important to this thread, the thing that surprises me is the lack of undertanding of voltages and the effect on equipment it potenially has with Electricians in the UK

all equipment sold in the UK should be rated for that full voltage range.

Similarly all installations including cables, MCBs etc should be sized to be capable of carrying the maximum current that unit can produce at all voltages. If it's not then that's not the fault of solar PV installations, it's the fault of whoever under-specified the cable / MCB in the first place.

If the local grid is going outside the allowable voltage limits due to solar installations, then it probably means those systems inverters haven't been set up properly to G83 protection settings, and the DNO would have the power to require those systems to be disconnected.

btw - the allowable instantaneous voltage limit is 264V, 253 is the maximum 10 minute average voltage.

fwiw, Northern PowerGrid have recently dropped the voltage across their networks by 6V to allow for greater solar PV input / reduce over voltage issues - many of which were actually down to the grid delivering power above the 253 limit prior to the PV being installed anyway.

There will be more and more issues around this, but if installed to current standards the issues should more be around voltage swings around the 253V mark as inverters cut in and out. We're hopefully going to be trialling a system with Northern PowerGrid to resolve this issue by setting the inverters to reduce their output as it approaches the voltage limit instead of just cutting in and out.

 

[GLENNSPARK]

this post is second only to Tony's upside down reply to a guy working in oz earlier, brilliant post, I'm still chuckling here, we need a funny post of the month award here, just brilliant haha

aye....and back to front n all....
come on mike....dod you see the `content` of what he was askin?...lol......lol...