RCD cutting out at same time every night.

[spin0304]

HELP! We are in a 10 month old house & the electrics keep tripping the same time every night - 7.10pm. We have written down all the things that are switched on when it happens and have switched off as many as possible before it's due to go off. The only things left on are the boiler and fridge. The boiler/heating/timer is not timed for 7.10pm (nor is the fridge!) - can anyone shed light on what could be causing this? The main RCD for the house is what cuts out. There is another RCD in the garage (where the boiler is) but that is not cutting out but with the main one off in the house, it affects the heating system too. Anyone any ideas? PS. Have contacted the electrical company responsible for the installation of the electrics - they want £150 to visit the house before resolving the problem!

 

[JohnD]

you need to unplug things (not just switch off)

If is often watery appliances such as immersion heaters, kettles, boilers.

Sometimes it is heating elements like ovens.

It is very often outdoor things gettig wet with rain. including outdoor lights and sockets but also garages and outdoor cables.

 

[Diyisfun]

At 7.05 turn the boiler off at the mains, cant be the fridge no timer.

 

[JohnD]

If it is getting dark at 7.10 it might be a light on a timer

what time does your neighbour come home and out the kettle on?

What time do the street lights come on?

 

[Steve]

Does the fridge have a defrost heater? (Some frost free fridges/freezers have a 24h timed defrost) - our freezers at work defrost every 6 hours using long tubular heaters along the cooling fins (the fans cut off so the heat is contained). I took our old fridge freezer apart and saw theres a defrost heater that loops across the cooling fins. Just an idea, perhaps worth checking out if theres no timers you can see (when the RCD trips it will reset the fridge defrost timer for anotehr 24h)

 

[breezer]

have you a pond or outside lights?

anything got a light sensor on it?

 

[333rocky333]

(when the RCD trips it will reset the fridge defrost timer for anotehr 24h)

something like that may be possible, physically turn off the rcd at say between 2pm and 4pm for a couple of minutes.
Then see if it alters the tripping time to the new time.


Do the neighbours have trouble, it may be something on the supply external to the building causing it.
or are you on a meter that changes tarrifs about 7pm.
do you know the rating of the rcd trip
ie 10ma, 30ma, 100 ma, 300ma, it is stamped on it

 

[big-all]

just a thought

if you are running near to capacity is it possible somthing big nearby like a factory shutting down could cause the power to surge just enough to cause a trip!!!

 

[JohnD]

The source is not always in your own house.

I sometimes get nuisance tripping, always at weekend about midnight, usually saturday night. I suspect it is someone closing down machinery at the end of a shift, but have not been able to track down the source

 

[Lectrician]

When an RCD trips due to an external influence of some kind, it is typical to have some form of poor insulation reading somewhere on your NON RCD side of the installation which causes the trip.

DC sence RCD's (white flylead) are far more prone to tripping due to external influence.

 

[spin0304]

At 7.05 turn the boiler off at the mains, cant be the fridge no timer.

Have done this several times but the problem still exists.

 

[spin0304]

have you a pond or outside lights?

anything got a light sensor on it?

We don't have a pond but we do have 2 outdoor lights with sensors. They can be switched off separately from switches inside the house. We have done this but again the problem still occurs.

 

[spin0304]

just a thought

if you are running near to capacity is it possible somthing big nearby like a factory shutting down could cause the power to surge just enough to cause a trip!!!

We have contacted the local Power Distributor (not the electricity supplier) who have since visited our house and fitted a plug in meter (free of charge) to monitor for surges. It's still plugged in until they call back for it.

 

[spin0304]

(when the RCD trips it will reset the fridge defrost timer for anotehr 24h)

something like that may be possible, physically turn off the rcd at say between 2pm and 4pm for a couple of minutes.
Then see if it alters the tripping time to the new time.


Do the neighbours have trouble, it may be something on the supply external to the building causing it.
or are you on a meter that changes tarrifs about 7pm.
do you know the rating of the rcd trip
ie 10ma, 30ma, 100 ma, 300ma, it is stamped on it

No, our neighbours aren't having the same problem and their house is basically exactly the same as ours (built a couple of months before ours). Our electricity tariff has no change at 7pm but I'll check the rating of the rcd - what is the norm?

 

[spin0304]

Does the fridge have a defrost heater? (Some frost free fridges/freezers have a 24h timed defrost) - our freezers at work defrost every 6 hours using long tubular heaters along the cooling fins (the fans cut off so the heat is contained). I took our old fridge freezer apart and saw theres a defrost heater that loops across the cooling fins. Just an idea, perhaps worth checking out if theres no timers you can see (when the RCD trips it will reset the fridge defrost timer for anotehr 24h)

No idea if our fridge freezer has one of these. It is a frost free variety but the problem has existed since before we bought it.