pfc test

[m4fiaafg]

please can someone clarify something for me. when a prospective fault current test is performed at the supply side, is this to make sure that its lower than than, lets say 6ka of the breakers capacity or the supply fuse capacity. the reason i asked this question was i performed this test today on a single phase installation and was getting a reading of 19.9 ka should this be lower than 6ka of the breakers of lower than the supply fuse

cheers

 

[Sintra]

What was the result for your Ze? it seems the PFC reading is very high are you close to the supply transformer?

 

[Mark.W]

It's not the breaking capacity of the breakers that count. It's the breaking capacity of the main fuse, ie BS1361 Type I or II, BS88 etc.

 

[Des 56]

please can someone clarify something for me. when a prospective fault current test is performed at the supply side, is this to make sure that its lower than than, lets say 6ka of the breakers capacity or the supply fuse capacity. the reason i asked this question was i performed this test today on a single phase installation and was getting a reading of 19.9 ka should this be lower than 6ka of the breakers of lower than the supply fuse

cheers

Was this domestic ? What type suppliers fuse
19.9 KA is one monster reading for a single phase domestic
Are you absolutely sure of that reading

You are correct with why the test is done,however
Back up protection by the suppliers fuse (Bs 1361 typeII) covers a domestic installation to 100 amp, the fault protection is by the suppliers fuse on the load side,the consumer units are deemed to have a fault current rating of 16 KA regardless of the mcb ratings


This does not apply in commercial or industrial installations or houses with supplies greater than 100A.

 

[m4fiaafg]

my ze was 0.02 ohms

 

[m4fiaafg]

sorry mate i forgot to mention its a commercial property, howhever its a single phase supply 100a main fuse bs1361 ans ze is 0.02 ohms

 

[m4fiaafg]

so when i test at the origin it should be lower than the supply fuse, lets say 16ka and if im checking at a final circuit it should be lower than 6ka assuming its a bs 60898 type b, am i corect i seem to have forgotten

 

[ezzzekiel]

thats correct you are ensuring that the device you are testing can handle the full fault current without exploding