ELECSA Certification Scheme RE: IR, COntinuity and Elecsa assessment

[j_wheatley]

Hi guys, new here and just starting out. Have got my Elecsa assessment coming up Wednesday and just wanted to run a few things by you all as it seems a great forum to help. I have changed a CU as my job and whilst I believe all to be ok I just wanted to query a couple of things. Namely the cooker continuity reading on a 32A type B MCB is 0.95 ohms which when added to R1+R2 for calculated Zs comes in just under the tabulated maximum in table B6 in OSG. is this figure acceptable or should I measure Zs and enter this reading on test results as this would be the actual resistance of the fault path? secondly I carried out a Line connected to Neutral and earth insulation resistance test at the consumer unit as couldn't be sure I could disconnect all neons and sensitive equipment. my meter came back with 17.85 mega ohms. now it is greater than the 2 mega ohms required but just really wanted to check that this figure is within normal readings. it is in a 2 bed flat with 2 lighting circuits (new) two ring final circuits, an immersion heater, cooker and electric shower. I will be totally honest that I have done very little actual testing to date but want to change this by getting Part P registered and doing about four years worth of domestic installs before going on to take my 2394 testing C & G. any help would really be appreciated and if anyone has any tips on making sure I don't balls up my assessment I would be grateful as really nervous! many thanks in advance guys.

jay

 

[shanky887614]

how old is the house? you should get a lot higher if its a newish house.

has the house got problems with damp and what's the cable type?

 

[telectrix]

i'd be inclined to test each circuit separately L/N - E. you'll probably find that it's just 1 circuit is a bit low. conversely, the average IR per circuit is 17.85 x 7 = 125 Meg.

 

[j_wheatley]

believe the flat is newish although old colours throughout. cable is T & E red and black. also just to add I reread my message and I put cooker plus R1+R2 which is wrong I meant cooker R1+R2 is 0.95 and this is added to measured Ze which is 0.14

many thanks

jay

 

[shanky887614]

believe the flat is newish although old colours throughout. cable is T & E red and black. also just to add I reread my message and I put cooker plus R1+R2 which is wrong I meant cooker R1+R2 is 0.95 and this is added to measured Ze which is 0.14

many thanks

jay

sounds like a loose connection or a very long run.

what size cable is the cooker circuit in?

have you done long lead method if tightening the connections doesnt help?


(drum of singles, connector strip and null your leads)

 

[telectrix]

your measured Zs may well be lower due to parallel paths. but your R1+R2 does seem a bit high for a short 6mm circuit.check all terminations. 1 or 2 may be a tad slack.

 

[j_wheatley]

pretty sure the circuit is 4mm T&E and is approx. 6m from cooker to CU. will also do individual IR for each circuit and also the cooker switch has a socket so will measure Zs from there too. thanks guys

 

[shanky887614]

pretty sure the circuit is 4mm T&E and is approx. 6m from cooker to CU. will also do individual IR for each circuit and also the cooker switch has a socket so will measure Zs from there too. thanks guys

there is no way an r1+r2 should be 0.97 over 6m with a ze of 0.12

 

[telectrix]

there is no way an r1+r2 should be 0.97 over 6m with a ze of 0.12

agreed. even though you drive into ditches.

 

[shanky887614]

agreed. even though you drive into ditches.

reversed at high speed actually

 

[j_wheatley]

im going to check all connections and recheck them, then carry out the test again. perhaps I just need to do a bit more as I have very little testing experience so far. but will fully check everything possible and see what comes back, will also do a zs test on the socket. thanks

 

[shanky887614]

im going to check all connections and recheck them, then carry out the test again. perhaps I just need to do a bit more as I have very little testing experience so far. but will fully check everything possible and see what comes back, will also do a zs test on the socket. thanks

do a long lead method from the ccu and to the cable in the cooker point, it might be a jb inbetween but testing will be the only way to find out.
l

 

[j_wheatley]

ah right ok. well its a top floor flat and all wiring runs through the loft so there may be something up there. thanks shanky

 

[davesparks]

I'm a bit concerned by you asking whether or not you should carry out an EFLI test.
It is an essential part of the testing process, not carrying it out suggests a lack of knowledge on your part.

 

[telectrix]

blame colleges for trying to eliminate live testing.

 

[j_wheatley]

I will admit to not having a full range of knowledge yet, I was of the understanding that you could either measure Zs or calculate it using (R1+R2)+ Ze which I already measured. is this not correct? not being smart, really just want to pick up everything I can. thanks

 

[Richard Burns]

It is not actually required to do a live Zs test as the calculation from Ze and R1+R2 is the worst case, however it is always a good idea because it is at least a final check that all is OK.

 

[davesparks]

It is not actually required to do a live Zs test as the calculation from Ze and R1+R2 is the worst case, however it is always a good idea because it is at least a final check that all is OK.

Oh well that's ok then, shall we use the value of Ze obtained by enquiry instead of measuring that too?

Let's just not bother doing any testing and calculate the whole lot shall we?

After all the magical RCDs will save the day!

 

[Guest77]

I will admit to not having a full range of knowledge yet, I was of the understanding that you could either measure Zs or calculate it using (R1+R2)+ Ze which I already measured. is this not correct? not being smart, really just want to pick up everything I can. thanks

Gasp lol, well at least you have the DB in your house for the buffoons at elecsa to look at, quite frankly I am appalled at the lack of standards now in the trade, embarassed actually, providing you have 5 weeks under your belt, electricity in your house and 400 sobs in a brown envelope these days you are in pmsl.

 

[Leesparkykent]

[QUOTE ] I will admit to not having a full range of knowledge yet, I was of the understanding that you could either measure Zs or calculate it using (R1+R2)+ Ze which I already measured. is this not correct? not being smart, really just want to pick up everything I can. thanks [/QUOTE]

Reg 313.1

 

[Guest77]

Oh well that's ok then, shall we use the value of Ze obtained by enquiry instead of measuring that too?

Let's just not bother doing any testing and calculate the whole lot shall we?

After all the magical RCDs will save the day!

:rofl: lol that made me laugh, in Richards defence he is only stating the rules, although they stink regarding calculations of ZS lol

 

[j_wheatley]

thanks lee, so calculation is acceptable. I just need to retest the cooker R1+R2 as this reading is way off. mdj, as for only having to have 5 weeks under my belt and a cash payment, not entirely right for me anyway, did start this whole process a while ago but with having to hold down a full time job, and not even being able to get any experience by offering to work for free, just studying the books cannot give me all the knowledge I need. doesn't mean im going to get a self certifying scheme under my belt and go around doing things out of my league but I have to make a start somewhere. at least it means I can get going and build practical knowledge to go with the theory that way I can make a career myself, not cut corners and establish a good name and working practice if I could have afforded to be an apprentice that's what I would have done, but it didnt work out that way so this is how I have to do it. as long as I work safely and check, double check and triple check my work I don't think im doing wrong. thanks for your replies

 

[Guest77]

well how much experience on site have you obtained?

 

[Leesparkykent]

thanks lee, so calculation is acceptable. I just need to retest the cooker R1+R2 as this reading is way off. mdj, as for only having to have 5 weeks under my belt and a cash payment, not entirely right for me anyway, did start this whole process a while ago but with having to hold down a full time job, and not even being able to get any experience by offering to work for free, just studying the books cannot give me all the knowledge I need. doesn't mean im going to get a self certifying scheme under my belt and go around doing things out of my league but I have to make a start somewhere. at least it means I can get going and build practical knowledge to go with the theory that way I can make a career myself, not cut corners and establish a good name and working practice if I could have afforded to be an apprentice that's what I would have done, but it didnt work out that way so this is how I have to do it. as long as I work safely and check, double check and triple check my work I don't think im doing wrong. thanks for your replies

Yes calculation is an allowable method to determine Zs. As Richard pointed out in #2 Ze+(R1+R2) will give you the worst case value.

 

[Simonslimline]

Calculating Zs will not highlight any high resistances that may be present through MCB's etc.

Always best to directly measure it.

 

[Guest77]

Thats my boy, the Trainees know more than a lot of the sparks here chuckle

 

[Leesparkykent]

Thats my boy, the Trainees know more than a lot of the sparks here chuckle

Yawn..

 

[j_wheatley]

testing hardly anything which is where I want to gain more experience, I've worked installing external lighting and its maintenance for 10 years, where I could get it ive got experience on house rewires, new circuit installs, boiler installation, downlight installs. these are few and far between though.

 

[Guest77]

Yawn..

Hey Lee you love the banter really

 

[Leesparkykent]

Hey Lee you love the banter really

Yeah i do really lol :icon12:

 

[Guest77]

testing hardly anything which is where I want to gain more experience, I've worked installing external lighting and its maintenance for 10 years, where I could get it ive got experience on house rewires, new circuit installs, boiler installation, downlight installs. these are few and far between though.

my advice to you is to attempt to obtain work as an Electricians mate for 2-3 years on site before actually going into someones home and installing wiring because you do not know how to test it and assess if it is safe to leave, you have no testing experience and no installation experience except installing outside lights, you are not qualified and pose a risk to householders at the moment.

 

[j_wheatley]

ok cheers. thanks for the advice.

 

[Guest77]

ok cheers. thanks for the advice.

your very welcome, good luck.