Old Breaker Could Be The Culprit

Ring main tested everything all sound circuitry , mcb Wylex NB30 , 30a type 2 , suddenly trips say after 4 days, 2 days random etc , then doesn't reset , then resets again a day later , i think it could be the bi metallic strip on its way out or the solenoid , any pointers would be useful or if anyone has had similar experiences would be grateful  

Appliances, accessories?

Tests done on circuit? Any changes made? What appliances are plugged in?

How do you know that there's not a faulty appliance that's cause the problem? Have you swapped out the mcb to eliminate?

+1

Test circuit properly and that includes I/R

Swap MCB to eliminate that.

I've had s similar problem when it trips at "random" whenever someone stood on a particular floor board upstairs.

Sidewinder said:

Appliances, accessories?

Click to expand...

Omitted everything including FCU connections to boiler etc , I'm going to swap 30mcb down (problematic) with upstairs 30 no problems and see if that works , in the meantime ill order a secondhand NB30 on ebay

ProDave said:

+1

Test circuit properly and that includes I/R

Swap MCB to eliminate that.

I've had s similar problem when it trips at "random" whenever someone stood on a particular floor board upstairs.

Click to expand...

Hi dave yes IRd L/N N/E L/E , R1 R2 ring cross connect all the same readings , visual inspect at each socket all good connections , so it really only leaves the MCB, has to be that , can go for 4 days etc until mcb trips and no reset , got to be bi metallic strip heating over a period of time and faulty , I'm going to swap downstairs ring (problem ) with upstairs (no problem) and eliminate the MCB 

What current are the adjacent MCB's running at?

PM me your address, I'll stick one in the post to you, 

Been round the clients , guess what MCB stays on no trip , have now swapped up and down ring main breakers, if it goes again on upstairs ring (was originally on downstairs) then i know for sure its the breaker itself. its got to be a duration and temperature factor thats upsetting the MCB and causing the phantom trip 4 or 5 days after I've been