stef
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- Reaction score
- 66
Evening everyone,
this is an ongoing dilema now: I work in a factory, you walk from one end to the other and you are ready for the London marathon. Each end has a switch panel, fed by an outside transformer. Each panel consists
of several fused switch isolators, ratied from 100A to 400A. They are the old style GEC isolators fitted with BS88 fuses. You go near one of those panels and someone with a purple face shouts 'you don't switch off nothing' in other words, you can't silatemthe whole panel. So you can't measure Ze at any time. Not to mention the efford to disconnect the earthing arrangements to eliminate parallel paths. Next option is enquiry. You ring up SEC and ask for the Ze value of that particular area, it is eithe ' I don't know Ohms' or 'How wouls I know? It is not impostand anyway' so enquiry is a nono as well. I remember when I did the 2391 I asked about Ze and was told to measure it as enquiry is not reliable enough. So, do do a PIR or EUir how would you determine Ze? Is it OK to measure (R1+R2) and Zs and then calculate back to Ze? But then you still have the unknown actual value of Ze. What now, please? Any suggestions?
Thanks.sama:
this is an ongoing dilema now: I work in a factory, you walk from one end to the other and you are ready for the London marathon. Each end has a switch panel, fed by an outside transformer. Each panel consists
of several fused switch isolators, ratied from 100A to 400A. They are the old style GEC isolators fitted with BS88 fuses. You go near one of those panels and someone with a purple face shouts 'you don't switch off nothing' in other words, you can't silatemthe whole panel. So you can't measure Ze at any time. Not to mention the efford to disconnect the earthing arrangements to eliminate parallel paths. Next option is enquiry. You ring up SEC and ask for the Ze value of that particular area, it is eithe ' I don't know Ohms' or 'How wouls I know? It is not impostand anyway' so enquiry is a nono as well. I remember when I did the 2391 I asked about Ze and was told to measure it as enquiry is not reliable enough. So, do do a PIR or EUir how would you determine Ze? Is it OK to measure (R1+R2) and Zs and then calculate back to Ze? But then you still have the unknown actual value of Ze. What now, please? Any suggestions?
Thanks.sama: