Weird Nuisance tripping but with a twist today!!
Discussion
Sorry for long post!
We have two leccy supplies and having had a new itchen about 6 years ago, and both fuseboxes replaced with consumer units, we had nuisance tripping on the main house board which goes in fits and starts. All testing shows no issues, sparks WAS of the opinion that it was just an accumlation of the leakages across what is a lot of stuff plugged into each circuit.
We also have a potenitally "dirty" supply, being rural and overhead lines.
Some months it can be fine, other days it can trip twice, no real obvious reason, it has made tracing any issue tricky, but we've been reassured that on each investigation, (by two different electricians) all earths seem ok and there is nothing obviously dangerous.
But this morning, the power appeared to "trip". We are on the regs that mean the sockets go off (on rcd) but the lights and boiler stay on, I know it is different for modern installations where the lights would be on rcd also.
So today the tv goes off in bed, lights stay on, boilers going. Hosue alarm starts to blip, saying it is on backup power, so I trundle down the garage to reset the rcd.. only it is still in the upwards on position! I think it must be a mini breaker, but they are also all "on". I go back to check, all the downstaris sockets are off, alarm shows amber warn light and is blipping away, confimring it is not mains powered up...
Go back to CU, press the square "test" button, and it clicks and the switch fires downwards. I go to reset it, and it wont catch, then after two goes it catches, but the other consumer unit rcd then trips....er WTF? My missus says that on resetting the rcd once many years ago, it tripped across to the other board, but never to me.
So I reset both switches, go into the house and all is not on and working...
Rang the electrician who is coming on Tuesday now. He said that he cannot see how the rcd can "trip" but the switch stay up,and it muse be a connection fault, but it DID all go back on once the test switch was hit and the rcd then reset.
Could the rcd be knackered just through the years off nuisance tripping? Is it possible to have an RCD trip but the switch stay up, or is it a "mechanical" break of the switch, so in order to disconnect it MUST trip downwards
I wont be messing with it myself, but would appreciate anyone's opinions, as to what the problem may be so I can make sure the electrician gets the parts he may need if something is knackered. RCD is a 63A 2 pole 30Ma switch, made by proteous, part number 62/2/30t.
Electrican has previously menitoned fitting a 100MA rcd which they fit on comercial applications, but I am reluctant to have this if there is a fundamental fault that is a danger. However, I have read that nuisance tripping in larger hosues and circuits can merely be due to having a lot of stuff plugged in.
(the only thing we've ever noticed using that can "cause" a trip is the laptop power supplies, all other trips seem to be random when nothing obvious is switched on).
Any help or opinion welcomed
We have two leccy supplies and having had a new itchen about 6 years ago, and both fuseboxes replaced with consumer units, we had nuisance tripping on the main house board which goes in fits and starts. All testing shows no issues, sparks WAS of the opinion that it was just an accumlation of the leakages across what is a lot of stuff plugged into each circuit.
We also have a potenitally "dirty" supply, being rural and overhead lines.
Some months it can be fine, other days it can trip twice, no real obvious reason, it has made tracing any issue tricky, but we've been reassured that on each investigation, (by two different electricians) all earths seem ok and there is nothing obviously dangerous.
But this morning, the power appeared to "trip". We are on the regs that mean the sockets go off (on rcd) but the lights and boiler stay on, I know it is different for modern installations where the lights would be on rcd also.
So today the tv goes off in bed, lights stay on, boilers going. Hosue alarm starts to blip, saying it is on backup power, so I trundle down the garage to reset the rcd.. only it is still in the upwards on position! I think it must be a mini breaker, but they are also all "on". I go back to check, all the downstaris sockets are off, alarm shows amber warn light and is blipping away, confimring it is not mains powered up...
Go back to CU, press the square "test" button, and it clicks and the switch fires downwards. I go to reset it, and it wont catch, then after two goes it catches, but the other consumer unit rcd then trips....er WTF? My missus says that on resetting the rcd once many years ago, it tripped across to the other board, but never to me.
So I reset both switches, go into the house and all is not on and working...
Rang the electrician who is coming on Tuesday now. He said that he cannot see how the rcd can "trip" but the switch stay up,and it muse be a connection fault, but it DID all go back on once the test switch was hit and the rcd then reset.
Could the rcd be knackered just through the years off nuisance tripping? Is it possible to have an RCD trip but the switch stay up, or is it a "mechanical" break of the switch, so in order to disconnect it MUST trip downwards
I wont be messing with it myself, but would appreciate anyone's opinions, as to what the problem may be so I can make sure the electrician gets the parts he may need if something is knackered. RCD is a 63A 2 pole 30Ma switch, made by proteous, part number 62/2/30t.
Electrican has previously menitoned fitting a 100MA rcd which they fit on comercial applications, but I am reluctant to have this if there is a fundamental fault that is a danger. However, I have read that nuisance tripping in larger hosues and circuits can merely be due to having a lot of stuff plugged in.
(the only thing we've ever noticed using that can "cause" a trip is the laptop power supplies, all other trips seem to be random when nothing obvious is switched on).
Any help or opinion welcomed
Edited by s3fella on Sunday 12th February 14:57
RCD's do fail. I test them daily and we actually regard 'sensitive trips' as a positive not a negative because they will respond to fault current sooner than less sensitive trips if you follow my logic.
All appliances leak a small amount - typically 1ma is allowed per KW, so if your RCD is rated at 30 ma it follows that you would need 30 appliances or more to cause nuisance trips (unlikely). However, what I would do is to start to leave appliances off and record on a daily basis what is not connected. When you get a nuisance trip, record what appliances are on and then cross them off the list as you go.
Appliances which are prone to causing trips are:
Get the sparks to test the RCD with a proper RCD tester. It should not trip at less than 30ma and over must disconnect within 10 milliseconds for the majority. For the price of a new one (£25) and the hassle I would replace it.
Other questions to ask him are:
1) When is the property due for a periodic inspection?
2) When was wiring last changed/modified and if changes were made to the wiring, was the installation signed off properly and where is the cert?
If he is happy with the two above, then I would be looking for appliance faults
edited to add - I would not change the RCD to a 100ma device - that is not addressing the problem it is allowing a higher fault current to flow before it disconnects - if your children are allowing the fault current to flow - touching live and earth - how fast would you want that disconnection?
I don't have my guide or 17th edition here, can anyone else chime in the with the necessary info?
All appliances leak a small amount - typically 1ma is allowed per KW, so if your RCD is rated at 30 ma it follows that you would need 30 appliances or more to cause nuisance trips (unlikely). However, what I would do is to start to leave appliances off and record on a daily basis what is not connected. When you get a nuisance trip, record what appliances are on and then cross them off the list as you go.
Appliances which are prone to causing trips are:
- Dishwashers (small leaks caused by overfoaming of rinse aid - too much into the base which drips onto the circ pump is common)
- Washing machines - heater element scaled up, (no calgon etc) so element overheats, distorts then goes to ground.
- Coffee machines - same as above because the have smaller boilers which fur up quickly if not descaled, the element warps and grounds out.
- Boilers - igniter circuit, pumps, fan motors.
- PIR security lights (not in your case as not on ring main)
- Halogen downlighters with transformers (not in your case as not on ring main)
Get the sparks to test the RCD with a proper RCD tester. It should not trip at less than 30ma and over must disconnect within 10 milliseconds for the majority. For the price of a new one (£25) and the hassle I would replace it.
Other questions to ask him are:
1) When is the property due for a periodic inspection?
2) When was wiring last changed/modified and if changes were made to the wiring, was the installation signed off properly and where is the cert?
If he is happy with the two above, then I would be looking for appliance faults
edited to add - I would not change the RCD to a 100ma device - that is not addressing the problem it is allowing a higher fault current to flow before it disconnects - if your children are allowing the fault current to flow - touching live and earth - how fast would you want that disconnection?
I don't have my guide or 17th edition here, can anyone else chime in the with the necessary info?
Edited by Lord Flathead on Sunday 12th February 15:13
Cheers.
All the kitchen wiring was changed when the new install was made 6 years ago, and the sign off was obtained. However, we "launched" the kitchen Xmas eve, with a party, the first trip ocurred when the missus turned on her Kitchenaid mixer to do the cream for Xmas pud the next day! !
I have sometimes wondered if it could be being caused by another property? All the houses in the street are early 70s, most are original, all the renovated ones with more modern electrics seem to have problems. Of course it could be a wiring fault, but I wondered if the proximity of things like earthing rods could be not helping?
When we go away on hols, we turn all off bar the fridges, and it seems ok on return.
Kitchen is large, 3 fridges, lots of appliances, and it is electric only, no gas, so fairly high loads.
We have one fridge that was subject to a recall and had loads of innards repalced a few years aog, (Samsung) and a Bosch dishwasher, that did not need the bosch recall, and we have isolated these for an extended period by putting them on the second supply. Seems no different.
Regarding what I found today, ie the rcd "tripped" but the switch not moving, is that even possible, ie indicating it is knackered? Or is it the mechanical action of the swtich that disconnects?
All the kitchen wiring was changed when the new install was made 6 years ago, and the sign off was obtained. However, we "launched" the kitchen Xmas eve, with a party, the first trip ocurred when the missus turned on her Kitchenaid mixer to do the cream for Xmas pud the next day! !
I have sometimes wondered if it could be being caused by another property? All the houses in the street are early 70s, most are original, all the renovated ones with more modern electrics seem to have problems. Of course it could be a wiring fault, but I wondered if the proximity of things like earthing rods could be not helping?
When we go away on hols, we turn all off bar the fridges, and it seems ok on return.
Kitchen is large, 3 fridges, lots of appliances, and it is electric only, no gas, so fairly high loads.
We have one fridge that was subject to a recall and had loads of innards repalced a few years aog, (Samsung) and a Bosch dishwasher, that did not need the bosch recall, and we have isolated these for an extended period by putting them on the second supply. Seems no different.
Regarding what I found today, ie the rcd "tripped" but the switch not moving, is that even possible, ie indicating it is knackered? Or is it the mechanical action of the swtich that disconnects?
s3fella said:
Cheers.
Regarding what I found today, ie the rcd "tripped" but the switch not moving, is that even possible, ie indicating it is knackered? Or is it the mechanical action of the swtich that disconnects?
The fact it would not let you reset it, is normally because there is still a fault present and it will not latch. Another way to try and speed the process is to buy a plug in RCD and swap all the appliances (that are on a plug) through it until you find the culprit.Regarding what I found today, ie the rcd "tripped" but the switch not moving, is that even possible, ie indicating it is knackered? Or is it the mechanical action of the swtich that disconnects?
Regarding the neighbours and trips, I have not heard of that happening - but that's not to say it doesn't.
No, I mean the fact it tripped first but the switch did not move. It only moved when I hit the test button.
BUt the rcd power was definitely off with the rcd switch still in the upward, on position.
Once tested, it moved down, then reset after a couple of attempts.
I dont see how the thing can disconnect but leave the switch in the on postion!
BUt the rcd power was definitely off with the rcd switch still in the upward, on position.
Once tested, it moved down, then reset after a couple of attempts.
I dont see how the thing can disconnect but leave the switch in the on postion!
s3fella said:
Sorry for long post!
We have two leccy supplies and having had a new itchen about 6 years ago, and both fuseboxes replaced with consumer units, we had nuisance tripping on the main house board which goes in fits and starts. All testing shows no issues, sparks WAS of the opinion that it was just an accumlation of the leakages across what is a lot of stuff plugged into each circuit.
We also have a potenitally "dirty" supply, being rural and overhead lines.
Some months it can be fine, other days it can trip twice, no real obvious reason, it has made tracing any issue tricky, but we've been reassured that on each investigation, (by two different electricians) all earths seem ok and there is nothing obviously dangerous.
But this morning, the power appeared to "trip". We are on the regs that mean the sockets go off (on rcd) but the lights and boiler stay on, I know it is different for modern installations where the lights would be on rcd also.
So today the tv goes off in bed, lights stay on, boilers going. Hosue alarm starts to blip, saying it is on backup power, so I trundle down the garage to reset the rcd.. only it is still in the upwards on position! I think it must be a mini breaker, but they are also all "on". I go back to check, all the downstaris sockets are off, alarm shows amber warn light and is blipping away, confimring it is not mains powered up...
Go back to CU, press the square "test" button, and it clicks and the switch fires downwards. I go to reset it, and it wont catch, then after two goes it catches, but the other consumer unit rcd then trips....er WTF? My missus says that on resetting the rcd once many years ago, it tripped across to the other board, but never to me.
So I reset both switches, go into the house and all is not on and working...
Rang the electrician who is coming on Tuesday now. He said that he cannot see how the rcd can "trip" but the switch stay up,and it muse be a connection fault, but it DID all go back on once the test switch was hit and the rcd then reset.
Could the rcd be knackered just through the years off nuisance tripping? Is it possible to have an RCD trip but the switch stay up, or is it a "mechanical" break of the switch, so in order to disconnect it MUST trip downwards
I wont be messing with it myself, but would appreciate anyone's opinions, as to what the problem may be so I can make sure the electrician gets the parts he may need if something is knackered. RCD is a 63A 2 pole 30Ma switch, made by proteous, part number 62/2/30t.
Electrican has previously menitoned fitting a 100MA rcd which they fit on comercial applications, but I am reluctant to have this if there is a fundamental fault that is a danger. However, I have read that nuisance tripping in larger hosues and circuits can merely be due to having a lot of stuff plugged in.
(the only thing we've ever noticed using that can "cause" a trip is the laptop power supplies, all other trips seem to be random when nothing obvious is switched on).
Any help or opinion welcomed
Thats your problem right there.We have two leccy supplies and having had a new itchen about 6 years ago, and both fuseboxes replaced with consumer units, we had nuisance tripping on the main house board which goes in fits and starts. All testing shows no issues, sparks WAS of the opinion that it was just an accumlation of the leakages across what is a lot of stuff plugged into each circuit.
We also have a potenitally "dirty" supply, being rural and overhead lines.
Some months it can be fine, other days it can trip twice, no real obvious reason, it has made tracing any issue tricky, but we've been reassured that on each investigation, (by two different electricians) all earths seem ok and there is nothing obviously dangerous.
But this morning, the power appeared to "trip". We are on the regs that mean the sockets go off (on rcd) but the lights and boiler stay on, I know it is different for modern installations where the lights would be on rcd also.
So today the tv goes off in bed, lights stay on, boilers going. Hosue alarm starts to blip, saying it is on backup power, so I trundle down the garage to reset the rcd.. only it is still in the upwards on position! I think it must be a mini breaker, but they are also all "on". I go back to check, all the downstaris sockets are off, alarm shows amber warn light and is blipping away, confimring it is not mains powered up...
Go back to CU, press the square "test" button, and it clicks and the switch fires downwards. I go to reset it, and it wont catch, then after two goes it catches, but the other consumer unit rcd then trips....er WTF? My missus says that on resetting the rcd once many years ago, it tripped across to the other board, but never to me.
So I reset both switches, go into the house and all is not on and working...
Rang the electrician who is coming on Tuesday now. He said that he cannot see how the rcd can "trip" but the switch stay up,and it muse be a connection fault, but it DID all go back on once the test switch was hit and the rcd then reset.
Could the rcd be knackered just through the years off nuisance tripping? Is it possible to have an RCD trip but the switch stay up, or is it a "mechanical" break of the switch, so in order to disconnect it MUST trip downwards
I wont be messing with it myself, but would appreciate anyone's opinions, as to what the problem may be so I can make sure the electrician gets the parts he may need if something is knackered. RCD is a 63A 2 pole 30Ma switch, made by proteous, part number 62/2/30t.
Electrican has previously menitoned fitting a 100MA rcd which they fit on comercial applications, but I am reluctant to have this if there is a fundamental fault that is a danger. However, I have read that nuisance tripping in larger hosues and circuits can merely be due to having a lot of stuff plugged in.
(the only thing we've ever noticed using that can "cause" a trip is the laptop power supplies, all other trips seem to be random when nothing obvious is switched on).
Any help or opinion welcomed
Edited by s3fella on Sunday 12th February 14:57
In all seriousness the electrician needs to be able to test for faults properly, the amount of so called electricians I have seen meggering a circuit whilst the neutral is still connected is laughable. Unplug everything (this means everything), switch all spurs of etc and get the electrician to do an insulation test on every circuit that is protected, also get a ramp test done on the RCD. Then get him to megger a few appliances.
A couple of points.
You say the RCD switch was still in the on position, until you pushed the test button. This would suggest the RCD had not tripped at all. When you have lost power before has the RCD always tripped off?
Also I assume you where in bed? If so what time of day? I assume if you and the other occupants where also in bed. Other appliances around the house where not beeing used (washing machine/kettle/microwave). When the electrics have tripped before what sort of times & occupancy?
You say the RCD switch was still in the on position, until you pushed the test button. This would suggest the RCD had not tripped at all. When you have lost power before has the RCD always tripped off?
Also I assume you where in bed? If so what time of day? I assume if you and the other occupants where also in bed. Other appliances around the house where not beeing used (washing machine/kettle/microwave). When the electrics have tripped before what sort of times & occupancy?
Lord Flathead said:
Regarding the neighbours and trips, I have not heard of that happening - but that's not to say it doesn't.
It does - we've suffered this problem - I even posted on here. We've had our mains trip when next door incompetently wired in an external light years ago, then last year had a continual problem which turned out to be next doors builders having damaged a cable.We are on a TT earth rod system, although our earth rod is about 15m away from the neighbour's.
TooLateForAName said:
Lord Flathead said:
Regarding the neighbours and trips, I have not heard of that happening - but that's not to say it doesn't.
It does - we've suffered this problem - I even posted on here. We've had our mains trip when next door incompetently wired in an external light years ago, then last year had a continual problem which turned out to be next doors builders having damaged a cable.We are on a TT earth rod system, although our earth rod is about 15m away from the neighbour's.
I live in London so mostly all is TNC/S systems which are not as susceptible to nuisance tripping from neighbours. Most larger houses run from different phases so this should also not present a problem.
OP - have are you still getting nuisance trips?
I was assuming (I know) that as the OP says that he is rural and has overhead supplies that he may also be on a TT system. We were undergrounded(sp) last year but still on earth rods, the cables were put underground because the post that supplied us was rotten.
I know that you can get the electric company to provide an earth for a moderate fee, if the OP is using earth rods then it might be worth looking into?
The only reason I haven't got the conversion is the requirement for 19mm(? or 16mm I forget) earthing to be installed - I'm working that through the house every time I do a bit of work or decorating. I didn't want the upheaval of taking floors up to run it through.
I know that you can get the electric company to provide an earth for a moderate fee, if the OP is using earth rods then it might be worth looking into?
The only reason I haven't got the conversion is the requirement for 19mm(? or 16mm I forget) earthing to be installed - I'm working that through the house every time I do a bit of work or decorating. I didn't want the upheaval of taking floors up to run it through.
In ans to the question, no, I've never had the power trip on the sockets and the rcd stay in the on position before. All the mobs were in the on position too, so it is a bit of a weird one. I think I will order a new rcd.
30 quid for the 30 ma, 98 for the 100 mA. Seems like a quid per milliamp!
30 quid for the 30 ma, 98 for the 100 mA. Seems like a quid per milliamp!
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