r1 + r2 calculations

ohthatshowyoudo · May 5, 2011

ANY HELP ON THIS LADS APPRECIATED!!
ok haveing tested a 230v 50hz circuit 100mtrs protected by (mcb 16a type c max ZS 1.44) (20a contactor) feeding (4 x 400w sodium floods)... the readings were as follows ..(cpc r1+r2 = 1.47ohms) Ir=>1999 (Ze = 0.01ohms) pfc 6.00 ka/ are my calculations correct in checking shock risk.... Zs = Ze+r1+r2=ohms so Zs= 0.01 + 1.47 = 1.48ohms over so fails..
i also wanted to check the design calculation for this circuit and my mind is frazzeld as to what table and page in regs i can find the r1 + r2 milohms/per mtr calcs for 6mm swa

any help plz

KEVINDOE · May 5, 2011

Thanks Morph

...and tq

morph · May 5, 2011

anyway where you been you hairy beast i missed you

morph · May 5, 2011

topquark said:
Must admit to doing the same with those that should know better ... I think the main thing there was they had there collective head around how to calculate what the PFC (PEFC) was. At least JemmaJones did.

bless them

ohthatshowyoudo · May 5, 2011

Hi widler
i hope i was....its a three phase d/b...... 3 lead live l1 neutal brown earth 230v loop test and will be doing another test. so hopefully will get right readings

Sparky Ninja · May 5, 2011

ohthatshowyoudo said:
Hi widler
i hope i was....its a three phase d/b...... 3 lead live l1 neutal brown earth 230v loop test and will be doing another test. so hopefully will get right readings

A bit confusing with the " live l1 neutral brown earth" bit there?

You need to isolate the installation, remove the earthing conductor and apply the test to each of the three lines (L1, L2 & L3), the earthing conductor and the neutral if it is a three lead test instrument.