Electric comes and goes.

[prakhonchai nick]

My kitchen extension has 4 fluorescent lights and 2 double power sockets - one circuit 30 amp breaker.  Been there probably 8/9 years..All cabling hidden above the ceiling

In the past few days power has stopped for an hour or 2, then comes back on and goes off again a couple hours later.

If I switch the lights off, they do not come back on for another hour or 2

If lights are off, sometimes when I turn on, they light for a second and then go off. Power to the sockets is lost too.

I have replaced the breaker to no avail.

Any ideas?
 

[Gsxrnz]

Probably need new starters for the fluro lights.  But confusing why the power sockets die.

 

 

[bbko]

Bad wiring in the celling due to rat/mice?  We had a similar problem with the awning lights outside our house, after bulb changing, breaker checking, it turned out the wire were chewed.

[Crossy]

Can you check your supply voltage at the board and at an outlet in the kitchen?

 

If it all checks out OK then I'd be looking at chewed wires too I'm afraid.

[prakhonchai nick]

My cat has been quite active of late catching a few small  mice

 

Thanks for your feedback. Looks like mice is the answer. Will somehow have to thread a new cable from the circuit board to where the junction box is likely to be in the kitchen.

[Crossy]

If there's not already one in place cutting an access panel to the ceiling space would make the task much easier.

 

Make it removable to guarantee no issues in future.

 

[Led Lolly Yellow Lolly]

You need to establish if it's just the lights or whole house issue. If it's whole house, the first place I'd be looking is the LV side cutouts on the transformer. Obviously you're not going to be doing that, it'll be the PEA/MEA, but I know these are a common point of failure as they often go bad on our own transformers (we have 4 and I have my own set of hot sticks to replace the fuses).

Basically they're big blade fuses, but the blades are often ill-fitting, and the jaws need squeezing closer together so the blades of the fuses fit more snugly. Without a snug fit the connection oxidises and begins arcing. The arcing creates more oxidisation and from there it goes rapidly downhill. This lowers your voltage and it starts jumping all over the place. This is a very common cause of flakey power but it is little known by the average consumer.

 

The modus operandi of the PEA is to just bash them from the sides to move them closer together and make the fit more snug.

[Led Lolly Yellow Lolly]

I just walked to work and took this picture to clarify what I mean....

 

[millymoopoo]

Led Lolly Yellow Lolly is correct in describing a potential problem with the fuse/circuit breakers of the transformer, especially if they carry a high load for long periods of time.

As you can see from the photo there are 6 fuse/circuit breakers, 3 for the circuits heading left and 3 for the right hand side circuits.

However either or both circuits do not supply just one dwelling, many houses would be fed from both circuits.

Thus if your problem is not experienced by other households on the circuit you are on, you could eliminate the transformer fuse/circuit breakers as the problem.

The same principle can be applied to your house circuits, if all circuits in the house are effected, then you could well look at the supply cable, meter and street fuse as well as your main switch, safety switch and fuse.

If other circuits in the house work OK when the kitchen circuit plays up, that would suggest it is only the kitchen circuit that is the problem.

[vandeventer]

On 11/8/2021 at 9:45 AM, prakhonchai nick said:

My cat has been quite active of late catching a few small  mice

 

Thanks for your feedback. Looks like mice is the answer. Will somehow have to thread a new cable from the circuit board to where the junction box is likely to be in the kitchen.

Mice will eat anything. Last year they ate some wires in my car, so I put down sticky paper to catch them and caught 2 birds instead. I cleaned their feet and let them go. Never did catch the mice.

[Pdavies99]

Loose / burnt connections on either side of meter!  This is often the cause.

[The Theory]

Just check the voltage at the breaker output when the lights turned off by itself. If the voltage is present then check the voltage at the 2 sockets, if voltage is present at sockets then check the light switch and wires to the light from the switch. If there is voltage before and after the switch then problem could be Neutral line to the lights.  

[MrJ2U]

On 11/8/2021 at 7:14 AM, bbko said:

Bad wiring in the celling due to rat/mice?  We had a similar problem with the awning lights outside our house, after bulb changing, breaker checking, it turned out the wire were chewed.

Rats or mice in the crawl space chewing wires is so common.

 

Once you replace the wires get some sticky bate traps sprinkled with fragrant rice/poison mixture. 

 

Bayers is second generation poison and it'll take 5-7 days for the rats to die, hopefully outside foraging.

 

It usually this time of year the population explodes.

 

 

[prakhonchai nick]

Turned out to be a fault in the consumer unit.  For the 2nd time in a month the main 63amp breaker started melting. A new unit installed and all seems fine for now

[Crossy]

1 hour ago, prakhonchai nick said:

Turned out to be a fault in the consumer unit.  For the 2nd time in a month the main 63amp breaker started melting. A new unit installed and all seems fine for now

 

This is worrying.

 

Was the overheating traced to a particular cause (it would usually be a bad connection)?

 

Cooking a 63A breaker on overload (unless you're mining crypto) is not an easy task for most homes.

[prakhonchai nick]

The electrician seemed quite sure the consumer unit was the cause of the problem, and nothing else.  However with the language barrier I was unable to question him fully. 

[The Fugitive]

3 hours ago, prakhonchai nick said:

Turned out to be a fault in the consumer unit.  For the 2nd time in a month the main 63amp breaker started melting. A new unit installed and all seems fine for now

Thanks for letting us know. Very helpful and interesting information supplied by contributors to this thread!

[Led Lolly Yellow Lolly]

On 12/30/2021 at 5:25 AM, prakhonchai nick said:

Turned out to be a fault in the consumer unit.  For the 2nd time in a month the main 63amp breaker started melting. A new unit installed and all seems fine for now

I've not read this thread through again to refresh my memory of it but I know from bitter experience that main breakers will melt because the screws were not torqued properly onto the cable and they get extremely hot as a result. It will also explain the flakey power.

You also get idiot sparks that will cut down the cable to make it fit, sometimes only a few strands of copper. Obviously this is a point of extreme heat under load.

 

Also, if this is a plug in type CU, the cheap ones are garbage, as are the cheap plugin breakers. The plugin connections are unreliable. They WILL get hot under load on the lower quality end of the market. Also, the scrap coins from the 'knock-out' holes on the mild steel cases may get lodged in the bus bar if the installer was careless. Another possibility.

 

 

[captainjackS]

On 1/3/2022 at 8:45 PM, Led Lolly Yellow Lolly said:

I've not read this thread through again to refresh my memory of it but I know from bitter experience that main breakers will melt because the screws were not torqued properly onto the cable and they get extremely hot as a result. It will also explain the flakey power.

You also get idiot sparks that will cut down the cable to make it fit, sometimes only a few strands of copper. Obviously this is a point of extreme heat under load.

 

Also, if this is a plug in type CU, the cheap ones are garbage, as are the cheap plugin breakers. The plugin connections are unreliable. They WILL get hot under load on the lower quality end of the market. Also, the scrap coins from the 'knock-out' holes on the mild steel cases may get lodged in the bus bar if the installer was careless. Another possibility.

 

 

good idea to mention about the plug in breakers -- My Schneider SquareD CU has a label in it that says to NOT pry the tabs of the plug-in devices apart to make it easier to plug in.  The purpose is to have a super tight connection with minimum resistance (less heat) However, people often pry the tabs apart with a flat screwdriver to make the plug in breaker easier to push into the socket. Loose connection = more heat.  combine that with possible poor quality surface finish, moisture ingress, oxidation, ... downward spiral.