Having my finnaly apprentice exam at monday 11 - friday 15

[electricwoman]

I am taking my finnaly exam starting at monday-friday after 2,5 year as an apprentice offshore.
I will be taking the test at a test station onshore. Since its not longer possible to take it offshore.

It scars me and I am starting to get cold feet.
I have 5 days to do the test.

The test is split in two parts

One is the planning part
number two is the wiring and so on.

I cant start on the practicall part before wendesday.

I need to do a full test on the wiring system / full doc on the earth installation .
material list, tool list, calculate IK max/ IK min , making a plan for the working days ,
risiko analyse /hms plan, one line schematic for the inntake ( drawing of the installation with the main cercuite breaker, kwh measurerment) you know.
instrument list (witch instrument I will use)


I know for sure it going to be a typical house wiring on the first task
the other task will be a motor installation. maybe a star triangle faces or something.


Any tips?

I have a MFT 1552 tester

some question about the tester:
since the sensor will be starring when I do the test, maybe he wil ask some questions.

When I turn on the tester it says U3,5 after 5 sec it says 11,3V I figured out the last one has to be the battery power 1,5V*8=12V so I guess there is enough power for my exam and more.
But the U3,5 what is that?


The tester has a manual but its not very good decribed its only a few pages,
When I look at fluke they have a quite big one.

So if anyone have a guidline

What is the diffrent betwheen rcd autotest and manuell?
Can I use RCD auto as a rule for and ordanary wiring system house?


RCD autotest=


RCD manuell 1/2I= I 5I= <I =



LOOP Notrip= PFC= HI = PFC=


mA 10 30 100 300 500 1000 ? is that part of the manuell testing?


Does any one have some easy step to follow?
A pdf file to share , I wil write everything like documentation on my computer

 

[saveloy]

Megger MFT1502-2 Multifunction Tester. Buy online or call

If you click on the data sheets and downloads tab there is the full manual (pdf)for the Megger MFT tester.

The RCD autotest allows you to run the full range of RCD tests at once. All you have to do is reset the RCD each time it trips after the 1 x @ 0 and 180 degrees and the 5x @ 0 and 180 deg. RCD should not trip at 1/2 x rated trip current.

The manual test allows you to test the RCD at 1/2x 1x or 5x individually.

PFC is for measuremant of Prospective Fault Current ie between Line and Neutral Or between Live and Earth (KAmps)

The Loop test is for Earth Fault Loop Impedance Ie Ze or Zs. If there is an RCD on the circuit you are testing then use the No trip option.

 

[pushrod]

mA 10 30 100 300 500 1000 ? is that part of the manuell testing?

You set your tester to the mA value of the rcd you are testing whether it's on manual or auto. This will usually be 30mA especially for domestic. Using auto is easier than manual as you just have to reset the rcd when it trips.

edit: there are two clips on you tube about the 1552 [ame=http://www.youtube.com/watch?v=PniIhehMNf8]here[/ame] don't show the connections but useful for the settings on the tester, hope it helps.

 

[electricwoman]

Not sure what net system I will get on the test,
Have only testet the mft 1552 on a TT nett

But 30ma is probably what I will be testing, nomatther what system since you need to have 30ma fuses on every curcuite.


If I set my tester on auto test rcd an choose 10ma for a 30ma fuse then it wont brake?

If I set my tester on auto and use 30 ma fuse then it will brake?


So the only diffrents bethween automode and rcd manuell is that you get more values desplayed?
Its the complete same test as the manuell, only that you can take step by step?

Where is that function usefull?

since the autotest set on will it give a message if the fuse/ 30ma break before it shuld?


Not sure what the sensor exspect me to do but the auto function is very tempting to use

Is there any way to document by calculating ?

You set your tester to the mA value of the rcd you are testing whether it's on manual or auto. This will usually be 30mA especially for domestic. Using auto is easier than manual as you just have to reset the rcd when it trips.

edit: there are two clips on you tube about the 1552 here don't show the connections but useful for the settings on the tester, hope it helps.

great video thanks

Megger MFT1502-2 Multifunction Tester. Buy online or call

PFC is for measuremant of Prospective Fault Current ie between Line and Neutral Or between Live and Earth (KAmps)

The Loop test is for Earth Fault Loop Impedance Ie Ze or Zs. If there is an RCD on the circuit you are testing then use the No trip option.

SO PFC is only for IK 1pole, like in TN?



I cant test the IK 3 pole with this instrument i guess?

 

[pushrod]

If I set my tester on auto test rcd an choose 10ma for a 30ma fuse then it wont brake?

If I set my tester on auto and use 30 ma fuse then it will brake?


So the only diffrents bethween automode and rcd manuell is that you get more values desplayed?
Its the complete same test as the manuell, only that you can take step by step?

Where is that function usefull?

since the autotest set on will it give a message if the fuse/ 30ma break before it shuld?

you must set the tester to the the value of the rcd you are testing. It will trip the rcd at 1X and 5X the value and show the times which should be less than 300mS and 40 mS respectively - you record those values on your test sheet.

 

[electricwoman]

you must set the tester to the the value of the rcd you are testing. It will trip the rcd at 1X and 5X the value and show the times which should be less than 300mS and 40 mS respectively - you record those values on your test sheet.

the ramp is that the same function (auto)

 

[Sintra]

No.

Ramp is used to measure the amount of current in mA that it takes to trip your RCD.

Set the mA dial on the meter to that of the RCD to be tested attach test leads, start test and wait untill RCD trips.

 

[pushrod]

ramp test shows a value in mA that trips the rcd. the other rcd tests (auto and manual) give times in mS. Using auto saves you remembering to switch phase by 180 degree for each test.

 

[electricwoman]

Using auto saves you remembering to switch phase by 180 degree for each test.

It sends a fault mA first in L1 than it switch 180 deg and send a fault mA too L2 did I get it right?

 

[pushrod]

It sends a fault mA first in L1 than it switch 180 deg and send a fault mA too L2 did I get it right?

yes - if its in auto (for a 30 mA) RCD it will send 15mA for 200mS (if i remember correctly) it does not trip. then it sends 30mA - it trips and displays the time. You reset the rcd and it sends 30mA again but 180deg out and it trips again - you reset the rcd and then it sends 150 mA (5X) which trips it in less time - you reset and it sends 150mA again but again 180deg out. You retrieve the results (all the times) by pressing the red button by the yellow test button.

 

[electricwoman]

I found the other part of the video


[ame=http://www.youtube.com/watch?v=p_Blib9qUO0]YouTube - MFT1552 & MFT1553 Demo Part 2[/ame]


along with your discribtion and the others I am back on track for now,
at least I can sleep well intill tomorrow

I liked the autofunction, possibility of tracking back the results the man on the video tested that function.