RCBO Fault

[TripleD]

Hi,

Anyone have experience in the following:

16a MK RCBO Tripped supplying Garage. 2 Circuits. Radial and Lights (6/16) MCB's

PME supply. Garage supplied in 6mm Twin and Earth with the Earth connected at the Main DB and Connector Blocked in the garage (doing nothing). Earth rod to garage in 6mm Multistrand and connected.

Twin and Earth IR Line/Neu +999, Neu/Earth +999 and Line/Earth 0.01. Removed Earth from main Cu and RCBO stable and live.

Zs 46.6 using just the Earth Rod, connected at the sub board in the garage. RCBO test sequence all clear too. Plugged in Freezer and RCBO tripped. Re-set RCBO and the Freezer is now stable.

2 Questions

Do you connect the CPC on the T/E at the MAIN Db when using RCBO's to supply a garage PME supply?
Any ideas why the freezer tripped the RCBO initially when plugged in for the first time? Leakage currents? RCBO ramp test was 21.0mA

Cheers

 

[telectrix]

might have tripped on the MCB part due to inrush current. might be an idea to replace with a type C.

 

[buzzlightyear]

PME supply. Garage supplied in 6mm Twin and Earth with the Earth connected at the Main DB and Connector Blocked in the garage (doing nothing). Earth rod to garage in 6mm Multistrand and connected.

The begging question why is the earth connected to the earth at the main board
And its a TT in the garage Is their any water pipes in the garage?

 

[Strima]

The CPC for the distribution circuit should be connected to earth at source.

How old is this freezer? Could be its just getting old and drawing too much current on start up. A standard domestic freezer should work quite happily on a B curve MCB.

 

[snowhead]

Twin and Earth IR Line/Neu +999, Neu/Earth +999 and Line/Earth 0.01. Removed Earth from main Cu and RCBO stable and live.

Is that statement correct?

If the freezer hadn't been plugged in for a while it may have a fault on it when the compressor is cold and now powered it's gone.
However it may return if it's ever turned off or it gets cold in the garage.

 

[Dartlec]

Hi,

Anyone have experience in the following:

16a MK RCBO Tripped supplying Garage. 2 Circuits. Radial and Lights (6/16) MCB's

PME supply. Garage supplied in 6mm Twin and Earth with the Earth connected at the Main DB and Connector Blocked in the garage (doing nothing). Earth rod to garage in 6mm Multistrand and connected.

Twin and Earth IR Line/Neu +999, Neu/Earth +999 and Line/Earth 0.01. Removed Earth from main Cu and RCBO stable and live.

Zs 46.6 using just the Earth Rod, connected at the sub board in the garage. RCBO test sequence all clear too. Plugged in Freezer and RCBO tripped. Re-set RCBO and the Freezer is now stable.

2 Questions

Do you connect the CPC on the T/E at the MAIN Db when using RCBO's to supply a garage PME supply?
Any ideas why the freezer tripped the RCBO initially when plugged in for the first time? Leakage currents? RCBO ramp test was 21.0mA

Cheers

Is the garage separated from the house? If so hopefully the T&E is run in some form of conduit? I assume there was a reason originally for them not to want to export the PME - Metal structure? Pipes?

The earth would be connected at the MAIN db to protect the cable (as armour would be if it was SWA) . If the L-E reading was 0.01 on the T&E with it disconnected at both ends then there is damage to the cable which would need to be found.

 

[westward10]

You do not export PME you are utilising a cpc derived from a PME earthing system.

 

[Dartlec]

You do not export PME you are utilising a cpc derived from a PME earthing system.

Noted - I was going from the terminology in an article I read a little while ago from Stroma in PE

 

[pc1966]

If the L-E reading was 0.01 on the T&E with it disconnected at both ends then there is damage to the cable which would need to be found.

I was wondering about that. Sounds like a damaged cable, nail through it, or crushed somewhere

 

[suffolkspark]

100% a damaged cable L-E, why are we all here?