303 exam tomorrow

[btwo5]

hi i have my 303 fault finding exam, tomorrow and i sort of no what faults im going to find.

i just need help to write up what i would need to do to remedial the fault.

ie : high r1 + r2 reading, low installation resistance reading, and no earth in 1 of the sockets

 

[Zeespark]

What tutoring have you been given on fault finding/rectification BT?

AndyGuinness

 

[btwo5]

What tutoring have you been given on fault finding/rectification BT?AndyGuinness

about 2 workshops looking visual, wrong polarity, no sleeving, low ir meaning, and the coding for faults, (code 1 2 3 4 )

i no how to do all the testing and i know about the what the readings mean and what to look for when doing visual

, im not to sure on the write up on how to rectify, only one i know is if i get a low ir on ring, and that would be half the ring test the 1 half switch of the socket 1 by 1 etc,

 

[Zeespark]

I would read through your paperwork again, do you have any reference books on electrical installation? alot of the info that you need would be found in those.

AndyGuinness

 

[btwo5]

I would read through your paperwork again, do you have any reference books on electrical installation? alot of the info that you need would be found in those.AndyGuinness

i got my sylabus booklets, osg and regs,

 

[Zeespark]

That should be enough to get you through the exam.

AndyGuinness

 

[btwo5]

That should be enough to get you through the exam.AndyGuinness

i done my exam, pretty simple only problem i had is about the rectification method to fix a 26.6 ohm reading on r2 to a cooker switch,

any chance you could tell me how id go about fixing that and the PIR code for it ? eg 1 for immediate requirement (ie wrong polarity)

 

[Zeespark]

So you have a high resistance joint, how do you think it should be dealt with? the EICR code should be looked as a list of codes and which one best fits the situation.

AndyGuinness

 

[btwo5]

is that all i should be writing for the rectification process

remove the cover off the cooker switch visually check to see if any connections are loose, if there not loose tighted the connections up and place the switch cover back on and retest the cooker r2 ?

would that work for the rectification method and maybe the PIR code as a 2 ?

 

[Technician]

Just to expand on what Zee has said, The tracing of the

faults can be done if you carry out the tests in the right

manner and carry them out in the right order.

Fault finding can be carried out using the half-split method.

As long as you know what the circuit type is, you know the

test procedures and have some idea of when a read is not

correct, you are in with more than a chance.

You may get a read of R1/R2 on a circuit and find that this

is unacceptable. Splitting R1 from R2 you may discover

that R1 has a higher read than R2 which, in a radial circuit,

is suspect because the CPC is smaller than the line conductor

if singles are not used.

This is just an example but pay close attention to the conductor

sizes and the information within BS7671 on allowable values

of Zs.

 

[btwo5]

Just to expand on what Zee has said, The tracing of the faults can be done if you carry out the tests in the right

manner and carry them out in the right order.

Fault finding can be carried out using the half-split method.

As long as you know what the circuit type is, you know the

test procedures and have some idea of when a read is not

correct, you are in with more than a chance.

You may get a read of R1/R2 on a circuit and find that this

is unacceptable. Splitting R1 from R2 you may discover

that R1 has a higher read than R2 which, in a radial circuit,

is suspect because the CPC is smaller than the line conductor

if singles are not used.

This is just an example but pay close attention to the conductor

sizes and the information within BS7671 on allowable values

of Zs.

ive found the fault, it was a high cpc reading, earth at board to all earth points, the cooker had 26.6 ohms

i just need to write up the method to rectify it, would this work

take of the cooker switch cover check to see if the cpc is loose if not re-tighten the connection re-fit the cover and retest to see if the ohm reading goes to a suitable reading.

i'd give that a 1 maybe 2 PIR code

 

[Zeespark]

That's the correct way, but always retest after screw tightening as it may not always be one loose connection. I could have told you this at the start, but you wouldn't have learnt nearly as much as you have, sometimes its better just to give students a nudge in the right direction.

AndyGuinness

 

[btwo5]

That's the correct way, but always retest after screw tightening as it may not always be one loose connection. I could have told you this at the start, but you wouldn't have learnt nearly as much as you have, sometimes its better just to give students a nudge in the right direction.AndyGuinness

thanks very much, only fault i wasnt to sure on, got the write up and the 16questions this monday

how many years/months should a storage unit turned into a workshop be tested ?

 

[NozSpark]

ive found the fault, it was a high cpc reading, earth at board to all earth points, the cooker had 26.6 ohmsi just need to write up the method to rectify it, would this work

take of the cooker switch cover check to see if the cpc is loose if not re-tighten the connection re-fit the cover and retest to see if the ohm reading goes to a suitable reading.

i'd give that a 1 maybe 2 PIR code

The thing to remember when coding a PIR is that a C1 is only for a fault that is of "IMMEDIATE DANGER", i.e. exposed live parts

 

[btwo5]

The thing to remember when coding a PIR is that a C1 is only for a fault that is of "IMMEDIATE DANGER", i.e. exposed live parts

i had to faults with wrong polarity so i made them a 1, should a high r2 reading be a 2 then ?

 

[NozSpark]

Here's a link to the ESC best practice guides, your after guide 4 issue 3

Best practice guides : Electrical Safety Council

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i had to faults with wrong polarity so i made them a 1, should a high r2 reading be a 2 then ?

I would say that incorrect polarity and a high R2 would be a C2

Any C1's should be rectified or isolated immediately