New CU keeps tripping
- Thread starter dx90
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Probably just plugged in but as I have said, as it isn't taking out the 30mA device it is more likely to me to be a problem on one of the lights / cooker / boiler circuits which is directly fed from the 100mA RCD.
Spark123 Have I got this right, the 30mA RCD is for earth leakage faults on anything that is connected to it when tripped?
The 100mA RCD is for the cooker, boiler and lighting earth leakage fault when tripped?
All the MCB'S are for over loading that circuit?
What would you suggest to be the best thing to do, turn off each circuit for a time and see if I can track down what one if it is just one of them that is causing the tripping?
The 100mA RCD is for the cooker, boiler and lighting earth leakage fault when tripped?
All the MCB'S are for over loading that circuit?
What would you suggest to be the best thing to do, turn off each circuit for a time and see if I can track down what one if it is just one of them that is causing the tripping?
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Yeah, when the 30mA device is off, all the circuits connected to it will be off. When the 100mA is off I take it everything on that board including everything connected to the 30mA device is off? It will probably be that the 100mA device is feeding the 30mA device.
Have you any outside lights? Try to narrow down what is switched on when the RCD trips, possibly the cooker?
Have you any outside lights? Try to narrow down what is switched on when the RCD trips, possibly the cooker?
Start by getting your electrician to sort the lights.
You could then try turning off the cooker by its double poled isolator.
The boiler could equally be a culprit.
Like I have said on a number of occasions, I'd look at those first before looking at appliances which are connected via the 30mA device as you say the 30mA RCD is not tripping.
You could then try turning off the cooker by its double poled isolator.
The boiler could equally be a culprit.
Like I have said on a number of occasions, I'd look at those first before looking at appliances which are connected via the 30mA device as you say the 30mA RCD is not tripping.
Ok Spark123 will do. Its going to be a few weeks before the electrician can com back to sort out the lights and I have a boiler engineer coming out next week to test the boiler for earth leakage. The cooker has just been tested by a Hotpoint technician last night and he said it had passed his tests.
Just an update.
The appliance engineer came out and could not find any fault with the dish washer and the boiler engineer came out and could not find anything wrong with the boiler.
Since the electrician came out and pointed out the faults was probably with the boiler and or the dishwasher, two extension leads and an alarm clock that I am still using all of the above due to not being able to afford to replace them yet. I have not had one trip since we could the electrician back because of the RCD 100mA tripping.
Very weird indeed. What do you think about this?
Thanks
The appliance engineer came out and could not find any fault with the dish washer and the boiler engineer came out and could not find anything wrong with the boiler.
Since the electrician came out and pointed out the faults was probably with the boiler and or the dishwasher, two extension leads and an alarm clock that I am still using all of the above due to not being able to afford to replace them yet. I have not had one trip since we could the electrician back because of the RCD 100mA tripping.
Very weird indeed. What do you think about this?
Thanks
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You could do with hiring a mA clamp meter. Stick this on the main earthing conductor to see what is draining to earth.
That's probably the background leakage from all your circuits and appliance added together. This will fluctuate depending of time of day, what is in use, and even dampness in the air.
If it was 40mA that is a bit high though not unusual in an older house.
The problem is that small leakages, individually not dangerous, add together enough to trip an RCD if it carries multiple circuits. The culprits are most usually watery appliances, like washing machines, kettles and immersion heaters; and those with heating elements, like ovens, immersion heaters, and kettles. Steam irons can be very bad.
An alternative method is to use a separate RCD on each circuit, this can be done using a thing called an RCBO (I use them) but of course it does work out more expensive.
If it was 40mA that is a bit high though not unusual in an older house.
The problem is that small leakages, individually not dangerous, add together enough to trip an RCD if it carries multiple circuits. The culprits are most usually watery appliances, like washing machines, kettles and immersion heaters; and those with heating elements, like ovens, immersion heaters, and kettles. Steam irons can be very bad.
An alternative method is to use a separate RCD on each circuit, this can be done using a thing called an RCBO (I use them) but of course it does work out more expensive.
Just had Hotpoint deliver and fit our third new cooker in as many weeks. They put a test on all the sockets in the house and said the reading is showing high resistance on all our sockets and said the cooker is fine it’s defiantly our electrics that are at fault. They said it looks like the CU as all the sockets are showing 100 Ohms and not 10 Ohms like it should do.
Is this correct?
Is this correct?
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