Is 3.16KA a very low reading for PFC.
Is there likely to be a problem or am I reading it wrong?
Is there likely to be a problem or am I reading it wrong?
PFC Reading
- Thread starter Nijinski001
- Start date
Quite high actually.
This value will alter hugely with many factors.
Cable length
Cable cross section
Circuit loading
Cable temperature
Sub Station size
Where are you measuring? At the origin of the installation it will always be higher than at a circuit end.
Closer to the substation will always be higher than the furthest supplied property.
Small subs on poles in the country have a relativly high internal impedance.
A cable carrying loads of load will have a slightly higher impedance, and hence a lower PSC. (not a good example, the difference is not huge!).
This value will alter hugely with many factors.
Cable length
Cable cross section
Circuit loading
Cable temperature
Sub Station size
Where are you measuring? At the origin of the installation it will always be higher than at a circuit end.
Closer to the substation will always be higher than the furthest supplied property.
Small subs on poles in the country have a relativly high internal impedance.
A cable carrying loads of load will have a slightly higher impedance, and hence a lower PSC. (not a good example, the difference is not huge!).
The measurement was taken at the point of entry to the property.
I'm not sure how far away the substation is.
This property is not in the country, in fact it's only 2 miles from the city centre.
I did a reading for another property recently that was just short of the maximum 16KA. I assume the property was near the substation.
Is it normal to get readings so low? At what point should I start to become concerned?
I'm not sure how far away the substation is.
This property is not in the country, in fact it's only 2 miles from the city centre.
I did a reading for another property recently that was just short of the maximum 16KA. I assume the property was near the substation.
Is it normal to get readings so low? At what point should I start to become concerned?
you want to be concerned about a high ELI, not so much with PFC. PFC is mostly needed to make sure protection can blow/trip with that kinda current. no point in gettin a 1KA MCB with a PFC of 16KA. MCB will probably weld together is there was a dead short... altho there is the main service fuse as backup
City centres often have large PFC readings due to huge subs.
K
kai
On a TNCS or PME system, a 3kA PFC is very good, as it's well within the range of modern 6kA MCB Breakers, and will operate the fuses or breakers very quickly indeed, in the event of an earth fault occuring.
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