PFC

[WSDLTD]

Currently on a instalation that i am working on the PFC is around 11.4KA this is a tt system, should by sorting out a new earth rod and the bonding bring this figure down any??

Ps Having a right Blonde day excuse the stupidity!

 

[Spark123]

The PFC will be phase to neutral won't it? An earth rod may affect a PEFC but not a PSCC. What size/type is the cutout fuse?

 

[WSDLTD]

well!! the 1361 is a 100a the main switch is a 100a the only problem i have is that i am using the type b 6k breakers which should a fault occur they will obviously POP! The 11.4KA is the PFC whilst testing the ZE which does incorperate the earth doesnt it. ??????

 

[RF Lighting]

A TT supply with a Ze of 0.02 ohms.

Are you quite sure about this?

 

[Spark123]

Does seem strange for a TT supply unless there are parallel paths through MEBs? The 100A BS1361 should provide backup protection, you'd need to verify this with manufacturers.

 

[WSDLTD]

you know what this is what i have been thinking, the figures that i have stated are all from a so called Approved contractor who has done a inspection and test and i am now carrying the rewire out as it has failed. the resistance he has stated is 2.42 ohms with a PFC of 11.4KA this doesnt work does it! if this is the case i think it is wired direct from the station

 

[ricicle]

Sure its not 1.14kA

 

[WSDLTD]

no definately 11.4 because he has failed the installation on it.

 

[Spark123]

What is the PEFC and what is the PSCC?

 

[Maxxy]

Did the tester know what they were doing? Where did they take the measurement from?

 

[ricicle]

Is the Tx pole in the garden

 

[RF Lighting]

 

[WSDLTD]

Doesnt state it on the sheet and as yet i have not tested the installation! you know what, im thinking its the first thing im going to be doing in the morning

 

[WSDLTD]

no its at the front of the house about 1m fron the consumer..............Nice picture , basic question - "what did you do"????

 

[ricicle]

Ah,Rf the old Metrel easi-test.I've got one of them.And I've also seen it >24kA many times on our overhead busbars.Good job they're all protected by BS88's