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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Electrical Questions >> Power surges when under high load https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1363816772 Message started by AndrewMGlasgow on Mar 20^th, 2013, 9:59pm

Title: Power surges when under high load
Post by AndrewMGlasgow on Mar 20^th, 2013, 9:59pm

Hi all,

I have a problem - not sure how big or small it is. For the last few months now, I have been suffering from intermittent flickering of my lights. It is not just the lighting circuit which is affected, as I can see my lamps flickering and even the lamp inside my electric oven is affected too.

Sometimes I can run as many appliances I wish and there are no problems. At other times, the flickering is quite concerning. One night last week when I was trying to read it was actually offputting trying to read that I gave up!

Even with very little loads it does it. When the flickering is taking place, it becomes more exaggerated the more appliances I run. For example earlier tonight I had the oven on, the microwave, and the kettle, and the lights were flashing like a disco.

The property is an old tenement circa 120 years old. This flat used to be part of the property upstairs, until it was subdivided in the mid 80s.

Consumer unit is a Memera 21. Looks a fair age as if its been put in when the flat was done in the 80s. Don't know how old the wiring is.

Initially I am thinking it is the consumer unit which is needing replaced. The only change I can identify over the past few months is the property upstairs has became occupied and they could be running high demand appliances which is causing my surges.

Anyone have any advice on how I should proceed? I want to get an electrician in but I don't want them telling me its a full rewiring job when its just the consumer unit which needs replaced, or even an external problem which the electricity network is responsible for.

Title: Re: Power surges when under high load
Post by AndrewMGlasgow on Mar 20^th, 2013, 10:51pm

This is the CU.

Don't like the look of lack of blanking plates, and the actual switches themselves don't appear to be secure/lined up properly. Not sure if this is material.

Title: Re: Power surges when under high load
Post by thescruff on Mar 20^th, 2013, 11:58pm

Hi, Not a sparky so just a few questions for when the boss turns up in the morning.

Where is the property located, country, town etc.

Is it an overhead supply and if so are you on the end of the line.

Was the supply ok before they moved in upstairs.

Is it better at certain times of the day, when the upstairs is at work for example.

Title: Re: Power surges when under high load
Post by Lectrician on Mar 21^st, 2013, 6:57am

This is usually down to a high resistance joint on the electricity supply to the flat. More than likely outside before it enters the building.

Do other people in the block have similar issues? Perhaps not everyone, but every third person (three phases).

Where is your electricity meter? You are responsible for everything after this point, and it could be a loose connection between there and (or in) your consumer unit.

I would check for tightness and signs or overheating or a fishy smell inside your consumer unit, and inside the switched fuse after the meter (assuming there is one). If all this looks OK, I would contact your DNO and report the problem to them (you may need to report via your supplier, as some DNO's do not allow direct contact). They will then check their side, and if nothing found, will fit a logger to log the voltage and demand over a period of time (weeks even). They will then check the data to see if the problem is theirs.

Title: Re: Power surges when under high load
Post by AndrewMGlasgow on Mar 21^st, 2013, 10:31pm

Lectrician wrote on Mar 21^st, 2013, 6:57am:

Thats very useful, thanks for that. Scottish Hydro are getting a call tmmw :)

Title: Re: Power surges when under high load
Post by AndrewMGlasgow on Mar 27^th, 2013, 12:14am

Just to let everyone know what happened with this, after the surges getting very bad tonight I called ScottishPower Networks who took a look at the connection coming into the property from the common close, and found that the wire coming into the property had burnt out. Was literally melting into the encasement of the switching gear.

The engineer replaced that wiring within half an hour, and now my lighting etc. is on solid regardless of how many applicances I run :)

One happy customer, no costs to me, and all is well.

Thanks for your guidance again.

Title: Re: Power surges when under high load
Post by Natedog on Mar 28^th, 2013, 4:23pm

did they say why it had happened?

Title: Re: Power surges when under high load
Post by Lectrician on Mar 28^th, 2013, 8:07pm

Loose connection with a heavy load. Bad combo.