MEM RCD/MCB tripping during night

[steviethepar]

Hi

Have a nightly problem - will be changing a consumer unit however have a problem customer has an older mem m6 32amp rcd/mcb on downstairs ring main only - this is tripping around 3-4am every morning told me had this off and on for a year. Not connected to anything on a timer eg heating / lights..

Unplugged / switched off everything and still happening , I have checked out circuit wiring and don’t have any faults also RCD test 1/2,x1,x5 and was ok - doesn’t happen during day so not been able to simulate

Anyone had this or wondering if some issue with older breaker / maybe voltage changes during night or something not thought off or just change our consumer unit and do more testing on wiring with all fully disconnected

 

[loz2754]

Hi. Could be a fridge that has a built in defrost cycle at the same time every 24 hours.

 

[timhoward]

Two thoughts...
1 - ramp test it
2 - (obscure one) It doesn't just happen to be very near a smart meter does it?

 

[snowhead]

Two thoughts...
1 - ramp test it
2 - (obscure one) It doesn't just happen to be very near a smart meter does it?

My first thought was point 2 as well, given issues with MEM and smart meters posted on here before.

 

[steviethepar]

My first thought was point 2 as well, given issues with MEM and smart meters posted on here before.

Hi cheers hadn’t seen about smart meters and MEM & there was one right next to CU will take a look through the forums

Will try ramp test as well actually annoyed I didn’t do that at time

Also fridge freezer thought about that and unplugged overnight still tripped

 

[ImpededLoop]

Two thoughts...
1 - ramp test it
2 - (obscure one) It doesn't just happen to be very near a smart meter does it?

I'd suspect the smart meter too. Memshield 1 RCBO's will trip when using a UHF 2 way radio whilst working on the DB, so a smart meter communicating could cause it. Next time you're there try sending a text whist close to the consumer unit to see if the RCD trips.

 

[steviethepar]

I'd suspect the smart meter too. Memshield 1 RCBO's will trip when using a UHF 2 way radio whilst working on the DB, so a smart meter communicating could cause it. Next time you're there try sending a text whist close to the consumer unit to see if the RCD trips.

Hi cheers popping in Tommorow and will try using phone/txt - and just spoke to customer has had this issue intermittent for 4 years - had smart meter since about then one of first ones installed - is only one circuit on MEM RCS/MCB (first Rcbos) and I’m sure has functional earth as well will need to double check

 

[Mikegh]

Obvious but just swop it out I reckon, see if the problem goes away

Had that said to me a few times about RCDs . Test them and connected wiring and I didn't think to swop them out

 

[timhoward]

I'd suspect the smart meter too. Memshield 1 RCBO's will trip when using a UHF 2 way radio whilst working on the DB, so a smart meter communicating could cause it. Next time you're there try sending a text whist close to the consumer unit to see if the RCD trips.

I’ve had this issue myself once, a simple google search pulls up plenty of cases. One chap built a cage around the CU to prove the point!

 

[steviethepar]

I’ve had this issue myself once, a simple google search pulls up plenty of cases. One chap built a cage around the CU to prove the point!

Hi

Following up I did ramp test 21mA and earth leakage monitored - had 6.4 on the ring circuit Rcbo and overall at meter tails 11mA - I am fitting and new box next week as well doing some other tests to prove the point - I spoke to an SSE engineer who denied everything

 

[catdog1121]

Hi

Following up I did ramp test 21mA and earth leakage monitored - had 6.4 on the ring circuit Rcbo and overall at meter tails 11mA - I am fitting and new box next week as well doing some other tests to prove the point - I spoke to an SSE engineer who denied everything

I would run a few extension leads to plug in fridge freezer etc from upstairs ring so that absolutely everything was disconnected from the downstairs ring.. This would tell you if its an appliance.

Really interesting comments about smart meters, I wonder if you could shield it some how.... Tinfoil?