Monitoring UK mains output

Hi,
My parents are having trouble with a TV and freeview box that is plugged into a particular wall socket (I am UK based), the problem is
that the freeview box keeps changing channels on its own and loosing its configuration. This only ever happens around 6pm most nights. To me it looks like there is a fault with the supply of electricity. I keep asking them to call the electricity board and get them to check it out but they are convinced that it is the freeview box that is at fault. They have also had numerous problems with video machines plugged into this socket as well in that they keep breaking down (they are using a 4 way adapter). My questions are:
1) Because it happens at roughly the same time at night could it be that there is too much power being sent down the mains cable to cater for the increase in demand (6pm means that many people will be cooking their tea) and this manifests itself in strange behaviour on the part of the freeview box?
2) Is there a device available that I can plug into the wall socket with a display on it that will tell me how much power is being sent through the mains socket and whether it is over or under the acceptable limits of a UK mains socket?
3) What are the acceptable limits of a UK mains socket, I've heard that it is 240v +/- 15%?
Thanks all Pusherman
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

It might be a dip due to some heavy load switching on at that time. You would probably notice this if you have a filament lamp running from the same supply (filament lamps accentuate the effect of supply dips).

Yes. Maplin have a plug-in power meter on special offer at the moment. This won't be any good for spotting transitry spikes/dips though. You would need a recording voltage monitor for that, but they're very expensive.

UK is 230V +10% -6%. All Europe was supposed to move to 230V +/- 10%, but several countries weren't ready so it was postponed. It's possible the UK has though (countries which are ready are allowed to).
--
Andrew Gabriel

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Andrew Gabriel wrote:

Thanks for the reply, Andrew. I'll have a surf over to Maplin and see what they have in the way of surge protection devices.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Pusherman wrote:

Could be the adapter. Do you mean one of those white cube shaped adapters with sockets on 4 of the faces, or a 4-way strip with a lead and plug? If the former, get them to ditch it or try a different one. They are often very badly made. If the latter, are connections sound at the plug, is the fuse in the plug a good tight fit (If it looks blackened that's a sign) and in the socket strip? Cheaper to buy a new one than get an electrician out.
A poorly suppressed igniter for a boiler can maybe cause impulses on the line which can affect electronic equipment. Is their boiler timed for 6 PM?

Electricity doesn't work like that. When demand is high, (an example often used is the ad break in Corrie) the voltage can drop briefly, but the people at Powergen can't 'send' more power just in case somebody might want it. If the surge in demand was enough to cause problems you'd notice the lights dimming.

A typical one is sold by Maplins for 13.49 Product code L61AQ

It used to be 240v +/- 6%, but voltages are now harmonized across Europe at 230v +10%, -6% I believe.
I think you should get an electrician to check the house wiring especially to the socket in question. It could be as simple as a loose wire making poor contact, heating up, sparking etc, again giving a 'noisy' supply to that socket.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.