Major domestic electrical problem

[atticus999]

Hi - looking for some expert help please. I recently had the following problem. Water heater digital timer burnt out, fridge/freezer, extractor fan and cooker hood all blown and will not restart (fuses all checked). It's the second time the water timer has burnt out in a matter of weeks - and suspect this caused the other appliance problems. I have had 2 electricians in to test and advise - neither could find any problem with the circuits and had no idea what caused the appliances problem. 3rd digital timer now installed. Clearly I need to get to bottom of this as I can't afford it to happen again. (I'm not an electrician BTW). Any help / advice gratefully received. Thanks in advance.

 

[Pete999]

Hi - looking for some expert help please. I recently had the following problem. Water heater digital timer burnt out, fridge/freezer, extractor fan and cooker hood all blown and will not restart (fuses all checked). It's the second time the water timer has burnt out in a matter of weeks - and suspect this caused the other appliance problems. I have had 2 electricians in to test and advise - neither could find any problem with the circuits and had no idea what caused the appliances problem. 3rd digital timer now installed. Clearly I need to get to bottom of this as I can't afford it to happen again. (I'm not an electrician BTW). Any help / advice gratefully received. Thanks in advance.

Do you have RCD protection on your CU (Fuse board)

 

[telectrix]

surge protection???

 

[James]

Could be a floating neutral,
Unfortunately you
Might need to find a better electrician, not all are good at fault finding.

 

[atticus999]

Do you have RCD protection on your CU (Fuse board)

Yes - the switches tripped - but apparently not enough to save the appliances.

 

[atticus999]

surge protection???

Not sure about surge protection - can it be installed?

 

[atticus999]

Could be a floating neutral,
Unfortunately you
Might need to find a better electrician, not all are good at fault finding.

I've no way of knowing if they're going to able to find anything - and it's an expensive process !

 

[DPG]

Strongly suspect broken neutral. Did you see lamps dimming etc prior to this? House built in1970s?

 

[Deleted member 105166]

How long have you been in the property?

Do you own or rent?

 

[happysteve]

If the appliances are blowing due to too high a voltage (and this isn't the only thing that could cause it, but I'd say it's the most likely), this is probably one of three causes:

(1) Transient overvoltages of atmospheric origin transmitted by the supply distribution system, and switching overvoltages

(2) Incorrect supply voltage

(3) High resistance neutral joint between the star point of three phases (say, 3 adjoining houses, each on a different phase) and the incoming supply neutral.

It's difficult to determine if (1) is the cause, without access to some pretty nifty monitoring equipment. To fix (1) you need a surge protective device (SPD) fitting at the origin of the installation.

Determining if (2) or (3) is the cause, you need some way to measure the voltage. Electricians have plug-in testers (multi-function testers) that will do this, but they can only measure the voltage there and then, and they won't pick up spikes/surges as in (1). You could measure the voltage safely yourself with something like a plug-in power/energy monitor, like this: NASHONE UK Plug Power Meter KWh Watt Energy Monitor with LCD Backlight Display. Electricity Meter to Measure Power Consumption and Reduce Energy Costs. 3680W: Amazon.co.uk: DIY & Tools - https://www.amazon.co.uk/NASHONE-Backlight-Display-Electricity-Consumption/dp/B07F9JJFR2/ref=pd_sim_107_1/257-5885365-2640615

If (2) or (3) is the cause, then your DNO (distribution network operator) needs to investigate.

I have suffered personally from (3). A few years ago I lived in a house with mural wiring: the three phases and neutral, supplied by an underground cable, were split between 3 houses using a joint on the rear wall of one of the houses, then distributed as single phase supplies to each house - known as mural wiring. The neutral joint started to fail, such that the neutral to all 3 houses was firmly jointed (very low resistance) to each other, but, with an intermittently high resistance to the incoming supply neutral.

The end effect was effectively a 3 phase star configuration, with a (partially) floating neutral, where each phase was in a different house.

This meant that if you put more load on in one house, the voltage on that phase (in that house) would go down, but the voltages in other houses would go up - often to higher than the permitted range. Hence the broken appliances (which Western Power payed to be replaced).

Fortunately, no fires or injuries.

 

[DPG]

A lot of houses built in the 1970s are suffering broken neutrals on the tee joints under the pavements.

 

[Wilko]

Hi - as there’s a good chance it’s a supply problem, maybe call your network operator (DNO) and ask for a safety check. Pop your postcode into this and it will give you a number to call.

Who is my network operator?

Who is my network operator?

www.ssen.co.uk

 

[Des 56]

Check with a "couple" of your neighbours to see if any of them have experienced problems with their electrics

 

[atticus999]

Strongly suspect broken neutral. Did you see lamps dimming etc prior to this? House built in1970s?

Lights do sometimes flash on and off (suspected dimmer issue)

 

[atticus999]

Check with a "couple" of your neighbours to see if any of them have experienced problems with their electrics

No-one else has had issues