t01474
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- Reaction score
- 18
Evening all.
Am currently doing my first EICR on a farm and have come across the following.
Supply is TNC-S.
There are many stables on the farm and various outbuildings.
At some of the stables / outbuildings a 3-core SWA has been installed but the CPC is not connected. Instead a separate CPC has been installed via an earth rod.
An example of the Zs reading is as follows -
Zs - 26ohms
PFC - 9.0A
But Zs between Neutral and Phase -
Zs - 0.08
PSCC - 2.9kA.
RCD's are installed upstream,ie, at the 'supply' side of the circuit in question.
So,
Am I right in thinking that an acceptable value of Phase -Earth is 200ohms as there is an RCD to protect against Earth fault, and that as long as the Zs for a Neutral - Phase fault (short circuit) complies with BS7671 then the results are fine or have I completely misinterpreted the idea?
Also, how close to a stable block / livestock transit path should an Earth rod be installed?
Any help /advise will be greatly appreciated. Sometimes I wish I was a painter. If the hardest decision I had to make each day was how to open the tin i'd be a happier man!!
Am currently doing my first EICR on a farm and have come across the following.
Supply is TNC-S.
There are many stables on the farm and various outbuildings.
At some of the stables / outbuildings a 3-core SWA has been installed but the CPC is not connected. Instead a separate CPC has been installed via an earth rod.
An example of the Zs reading is as follows -
Zs - 26ohms
PFC - 9.0A
But Zs between Neutral and Phase -
Zs - 0.08
PSCC - 2.9kA.
RCD's are installed upstream,ie, at the 'supply' side of the circuit in question.
So,
Am I right in thinking that an acceptable value of Phase -Earth is 200ohms as there is an RCD to protect against Earth fault, and that as long as the Zs for a Neutral - Phase fault (short circuit) complies with BS7671 then the results are fine or have I completely misinterpreted the idea?
Also, how close to a stable block / livestock transit path should an Earth rod be installed?
Any help /advise will be greatly appreciated. Sometimes I wish I was a painter. If the hardest decision I had to make each day was how to open the tin i'd be a happier man!!