2391 practical question

[dean7828]

hi chaps, i have my 2391 practical exam tonight and have a few things playing on my mind,

I'm sure i will have to test a 3phase db with a final ring circuit and a supply for a domestic type single phase db, my question is this....do i have to record the results for each db on separate schedule of test results forms or can i put them on the same form, also and most importantly do i have to record and do full tests on the supply to the single phase distribution board and record the results as any normal circuit within the 3 phase db.

any help and advice would be greatly appreciated.

 

[Sparky Ninja]

Your assessor should give you the relevant paperwork, so they will make the decisions for you. I give 1 x schedule of inspections and 2 x schedule of test results.

The supply to the single phase db will be recorded as a normal circuit on the schedule of test results for the three phase board. Record it as a distribution circuit.
You will then, at the single phase db, measure Zdb & pfc at that location. Record the pfc on the schedule of test results for the single phase db, but make sure you record the Ze measured from the origin on both schedule of test result (3 phase and single phase). The Zdb you have measured on the single phase board should also be recorded somewhere for reference. Some forms have a place for it, others don't it will depend on the forms you're given.

 

[dean7828]

ok cool so if i write distribustion circuit on scedual of test results for the 3phase board sheet no other information will be recorded? i supose i could fill in the distribution circuit conducter size and protective device details, and IR results up to the singlephase db.

 

[Sparky Ninja]

Check if the single phase db has been given a designation (db 2, or Garage DB etc) and record it as distribution circuit - 'designation'

You test it as a normal circuit. Think of it maybe as a normal final circuit (shower or cooker etc) and carry out the same tests as normal.
You will fill in all the necessary according to your schedule of test results (type, rating, conductor CSA's, continuity, insulation resistance, polarity etc)