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When measuring Ze on a TT that's RCD protected which is more accurate? Getting 27.1 on high current but 563 on no trip.
Discuss TT Ze reading- loop high or loop no trip? in the Electrical Wiring, Theories and Regulations area at ElectriciansForums.net
The TT is an offshoot of a PME system. The 6mm T+E supply is on 32A RCBO at the main CU and earthed to the MET.
I've installed a mini DB also Rcd protected but earthed it to rods. Obviously when I test high current (at the mini DB) it takes out the RCBO but gives the value 27.1. On loop no trip I get the very high value of 563.
Hi current testing should always be used for EFLI tests, except where this is made unfeasable by the presence of an RCD when a no-trip test might be used as an alternative.
Hi current testing should be your default method,
Is this 6mm T&E within the 50mm of wall surface to the mini DB.The TT is an offshoot of a PME system. The 6mm T+E supply is on 32A RCBO at the main CU and earthed to the MET.
I've installed a mini DB also Rcd protected but earthed it to rods. Obviously when I test high current (at the mini DB) it takes out the RCBO but gives the value 27.1. On loop no trip I get the very high value of 563.
The TT is an offshoot of a PME system. The 6mm T+E supply is on 32A RCBO at the main CU and earthed to the MET.
I've installed a mini DB also Rcd protected but earthed it to rods. Obviously when I test high current (at the mini DB) it takes out the RCBO but gives the value 27.1. On loop no trip I get the very high value of 563.
The introduction of the mini DB was to deal with the issue outlined in this thread
Exterior socket on PME system - http://www.electriciansforums.co.uk/threads/exterior-socket-on-pme-system.121435/
Under normal conditions there will be no discrimination that is correct but I was dealing with the issue of exporting PME.
So in the event of loss of PEN, the mini DB is earthed via rods TT. In that case during a fault I'd expect the mini DB to trip but not necessarily the RCBO at the main board.
Reply to TT Ze reading- loop high or loop no trip? in the Electrical Wiring, Theories and Regulations area at ElectriciansForums.net
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