Problems with fuseboard

[afc]

i have economy 7 storage heaters in my house the problem is the fuse panel has four fuses and one RCCB when the economy 7 comes on (Apporx 12.30 AM) the RCCB trip blows but none of the fuses blow X4 15 AMP 1 for each heater i can reset the RCCB but when you press the test button it does not activate the trip
please could anybody help me?

 

[ltheb]

Hi AFC, I am assuming the RCD is upstream of the four fuses, ie protecting the whole economy 7 installation. First off, just to explain the different functions of a fuse and RCD. A fuse (rewireable or mcb) is an overcurrent device and basically trips or blows when too much current flows for whatever reason. An RCD trips when there is an earth fault and protects YOU! and is much more sensitive. There may be a fault with one (probably) or more devices.
Test this by switching off all the appliances or removing the fuses or switching off the mcb's, then by process of elimination find out which one trips the rcd. If you feel confident, check the connections - a loose or burnt out connection could cause the problem. If they are re-wireable fuses, swicth off the RCD each time to prevent arcing when you remove the fuse. OTHERWISE get a qualified electrician to sort it out!

 

[JohnD]

...when you press the test button it does not activate the trip...

then it is either faulty or incorrectly wired. Since you say it trips on normal load I suspect incorrectly wired (or maybe severe cable damage)

When did it last work? Has it been recently fitted? Who by?

You say

...the fuse panel has four fuses and one RCCB...

which sounds very unusual. Storage heaters are not usually RCD protected.

Can you post a photo?

 

[afc]

thanks for reply have already checcked connctions have tried testing each fuse individually but circuit does not trip any of the fuses thanks for your help will need to get someone who is more capable then me many thanks

 

[Taylortwocities]

Test this by switching off all the appliances or removing the fuses or switching off the mcb's, then by process of elimination find out which one trips the rcd.

You may not find the fault by removing the fuses or switching off the mcb's. The RCD will trip if there is a fault to neutral. Removing the fuses or switching off the mcb's only disconnects the live side.

Each heater should have a double pole switch on the wall next to the heater. Switch them all off and see if the RCD trips. If it does you've got a wiring fault.
If it doesnt trip then switch each heater on one at a time until it trips - then you will have identified the faulty one.

Edit: the only time to try this is when the economy 7 is on. Also the test button will not work unless economy 7 is on. If the test button does not work then it needs looking at.

 

[afc]

thanks everybody who helped problem solved faulty immersion tank element