Electrical Engineering - Brownout in the UK

Author

Brownout in the UK - a doozy

Palindr☻me

2006-02-25, 7:21 pm

A good one tonite.

Power went off for a few seconds and then came back on at between 175
-190 volts for nearly 3 hours. The farm next door lost two phases
completely, apparently had the same wandering and low voltage on the
third and now have two out of the three back with nothing on the third.
It is going to be fun come milking time if all three aren't back. He
will just have to ditch the lot.

Any thoughts what could do that to a distribution system? I have never
seen a brownout like that before, in the UK.

I ran off the inverter for a while and then started the genny. I am not
sure what I have around the place that wouldn't be happy running of that
voltage for that length of time but didn't really want to find out.
Still, I know all my UPSs work ok now.

--
Sue

Phil Scott

2006-02-25, 10:21 pm

"Palindr?me" <me9@privacy.net> wrote in message
news:1201nmbehsvebe@corp.supernews.com...
>A good one tonite.
>
> Power went off for a few seconds and then came back on at
> between 175 -190 volts for nearly 3 hours. The farm next
> door lost two phases completely, apparently had the same
> wandering and low voltage on the third and now have two out
> of the three back with nothing on the third. It is going to
> be fun come milking time if all three aren't back. He will
> just have to ditch the lot.
>
> Any thoughts what could do that to a distribution system? I
> have never seen a brownout like that before, in the UK.
>
> I ran off the inverter for a while and then started the
> genny. I am not sure what I have around the place that
> wouldn't be happy running of that voltage for that length of
> time but didn't really want to find out. Still, I know all
> my UPSs work ok now.

dont run electric motors, refrigeration, pumps etc especially
3 phase on low voltage, you can easily burn them out that way.

Phil Scott
>
> --
> Sue
>
>
>

daestrom

2006-02-26, 11:21 am

"Palindr?me" <me9@privacy.net> wrote in message
news:1201nmbehsvebe@corp.supernews.com...
>A good one tonite.
>
> Power went off for a few seconds and then came back on at between 175 -190
> volts for nearly 3 hours. The farm next door lost two phases completely,
> apparently had the same wandering and low voltage on the third and now
> have two out of the three back with nothing on the third. It is going to
> be fun come milking time if all three aren't back. He will just have to
> ditch the lot.
>
> Any thoughts what could do that to a distribution system? I have never
> seen a brownout like that before, in the UK.
>
> I ran off the inverter for a while and then started the genny. I am not
> sure what I have around the place that wouldn't be happy running of that
> voltage for that length of time but didn't really want to find out. Still,
> I know all my UPSs work ok now.
>

Sounds like a fault in a substation. Probably a transformer. Often, three
single-phase transformers are connected together for supplying three phase
service. If something faults one, you get two hots and the third is dead.

As far as such low voltage, the most common suspect is when two or more
distribution transformers are tied to various parts of a line, and one goes
down, the remaining ones can't support the voltage over the entire length of
the line.

I'd have called the utility (in the US) and asked what they can do and how
long it will be. Don't try to run three-phase motors on single phase
though, they'll burn out.

daestrom

> --
> Sue
>
>
>

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