Z
zak325
Apologies if this question sounds a bit basic but am a little confused at the mo and quite new to the game. Here goes -
I am trying to complete a NICEIC Highway Installation Certificate for a system where there is a 230 v TT supply coming into a roadside pillar into the main BS88 fused head. 6mm Meter tails then take this into a 30mA RCBO which protects the sole circuit to an accessory.
So on the certificate I have 2 circuits - 1. Supply (Distribution) and 2. Final circuit to accessory (Final)
I know there is some debate on using the 1667 ohm / 200 ohm as max Zs for the protected final circuit figure but what should I use for the max Zs of the actual supply / distribution circuit ?
If i was working on a TN system I could happily just look up the max Zs figures using Table 41.2 but am a bit stumped with this TT scenario.
Any help on this welcomed. Thanks
I am trying to complete a NICEIC Highway Installation Certificate for a system where there is a 230 v TT supply coming into a roadside pillar into the main BS88 fused head. 6mm Meter tails then take this into a 30mA RCBO which protects the sole circuit to an accessory.
So on the certificate I have 2 circuits - 1. Supply (Distribution) and 2. Final circuit to accessory (Final)
I know there is some debate on using the 1667 ohm / 200 ohm as max Zs for the protected final circuit figure but what should I use for the max Zs of the actual supply / distribution circuit ?
If i was working on a TN system I could happily just look up the max Zs figures using Table 41.2 but am a bit stumped with this TT scenario.
Any help on this welcomed. Thanks