Problem with PSSC on three phase supply

[sparksburnout]

I have a domestic premises (it was once a shop) that has a three phase supply, although only one is being used now. I am using a di-log 9083P tester, and when doing a Ze test am getting 23KA as the reading for PSC, with 0.01 ohms as the loop resistance. I am getting a Ze of 0.35 ohms and a PFC of 565A. The values for PSC and L-N loop impedance seem unbelievably low to me? I am not sure where the local transformer is but it is not next door, I think it is about 400yds away. System is TNS. I have looked at the thread in the I&T forum, and used the method of inserting an impedance in the earth lead of the tester, but I am still getting the same readings, which as far as I can see you would, as it is for low Ze not low PSC. I have used the tester on about 3 other installations, and it is giving expected results. Could it be possible that these values are correct? In which case the main switch and breakers are well underrated!!

 

[telectrix]

I used to get around a lot but haven't been able to for the past couple of years cos I've not been well.

I always wanted a good camera outfit and after about 30 years finally got it - all packed in a big fluck off rucksack that I can't carry .......

go on then. keeping us in suspenders, what camera?

 

[Geordie Spark]

go on then. keeping us in suspenders, what camera?

Canon 30D

Old(ish) but does the job - a bit like you Tel.

Bag full of assorted lenses -Canon & Sigma, Sigma flashgun, Manfroto tripod and a monopod (one legged tripod) bits & bobs and I can't lift the bloody thing.

 

[tidyboiler]

Canon 30D

Old(ish) but does the job - a bit like you Tel.

Bag full of assorted lenses -Canon & Sigma, Sigma flashgun, Manfroto tripod and a monopod (one legged tripod) bits & bobs and I can't lift the bloody thing.

A bit like my make-up bag.

 

[trev]

Meanwhile back at the OP.
Might sound silly but how are you off for charge in the battery pack? Many testers start to give really daft readings if they're low.
I also think you may need to check your reading as it does not work out to 23Ka

 

[Geordie Spark]

A bit like my make-up bag.

I don't understand why you drag all that clarty stuff around with ye - ye divvent need it - yer bonny enough withoot it!!

 

[trev]

Furthermore, a Ze of 0.1 ohms at the distance you quote from the transformer is unlikely in my experience. I once did a rewire less than 50 metres from one and the reading I got was 0.47, considering how streets are wired this isn't beyond the realms of possibility but I checked it with different testers both very recently calibrated and they agreed.
I'd definitely be checking those batteries mate.

 

[Engineer54]

or on an eng54 installed rod. lol. :75:

As good as any of my earth rods may be, i somehow doubt they would have any influence on L-L or L-N fault currents!! lol!!

 

[telectrix]

Canon 30D

Old(ish) but does the job - a bit like you Tel.

Bag full of assorted lenses -Canon & Sigma, Sigma flashgun, Manfroto tripod and a monopod (one legged tripod) bits & bobs and I can't lift the bloody thing.

nice. i have the 10D. even older.does everything i need, though. only gripe i have is the size of the LCD screen 1.8".