Testing - Following an Addition

[steve100]

Addition to an existing circuit, if I was to instal an outside light and did so by taking a spur off the ring through a FCU, how would I test the the circuit to complete the minor works cert? I presume that I would carry out a continuity test on the ring as normal, but when it come to the spur is it okay to test at the lighting point and leave the fuse in place or should you bypass the fuse? Also when carrying out an IR test is it okay to leave the fuse in place?

Thx

 

[Marvo]

I can't help you with the minor works certificate as I've never seen one. This reply should bump your question so hopefully someone with more knowledge of this will chip in with some info.

 

[trev]

Test the RFC as you would normally and treat the addition as you would a spur. Fill in the mwc and job's a goodun

Finally I beat Paul to a question

Edit, yes you'd leave the fuse in otherwise you'll not get the circuit fully tested.

Edit Edit, don't forget to leave the lamp out and disconnect anything voltage sensitive, they don't like it up em you know.

 

[Paul.M]

"Finally I beat Paul to a question

"

Well done Trev, and its about time that you jumped in on this section because its been putting my gray matter to the test lol.

 

[trev]

I've been trying mate but you always beat me to the right answers, maybe I need to spend more time on here

Oops Julia just saw that and pointed to the front door

 

[Paul.M]

Theres only Marvo, me and you looking in on this section so you have a good chance mate. Think Ill post up some level 2 and 3 questions for the trainees to have a go at.

 

[steve100]

Edit, yes you'd leave the fuse in otherwise you'll not get the circuit fully tested.

Thanks Trev, So leaving the fuse in place wouldn't cause any false readings or damage the fuse then carrying out either the RFC continuity or IR tests?

I'm guessing thought that the IR wouldn't damage the fuse because the test current is in milli amps?

 

[trev]

No because you'll need it in there for your R1+R2 and polarity tests (which are done at the same time). You won't damage the fuse.
Are you ok with RFC testing or do you need guiding through the sequence?

 

[steve100]

I'm guessing thought that the IR wouldn't damage the fuse because the test current is in milli amps?

Thanks again Trev, I'm good with the RFC test sequence ta, so is my thinking also right in relation to the quote above?

Sorry also have something else to run by you in relation to the results of Zs, if the spur is run of the RFC then it is protect by a 32A MCB, then the FCU would have a 3A fuse and the cable running from the FCU to the light would be 1.5 T&E, so my question is when comparing your Zs test results against BS 7671 Impedance Tables, I prosume you would be looking for an impedance of < 1.16 ohms in OSG (for a 32A MCB) is this correct?

 

[trev]

Thanks again Trev, I'm good with the RFC test sequence ta, so is my thinking also right in relation to the quote above?

Sorry also have something else to run by you in relation to the results of Zs, if the spur is run of the RFC then it is protect by a 32A MCB, then the FCU would have a 3A fuse and the cable running from the FCU to the light would be 1.5 T&E, so my question is when comparing your Zs test results against BS 7671 Impedance Tables, I prosume you would be looking for an impedance of < 1.16 ohms in OSG (for a 32A MCB) is this correct?

Correct mate. I usually take the table in 7671 x 0.8. To be honest, if your RFC already complies I'd be surprised if a couple of metres in 1.5 T&E and a 3A fuse will make it non compliant

 

[Baker1988]

Theres only Marvo, me and you looking in on this section so you have a good chance mate. Think Ill post up some level 2 and 3 questions for the trainees to have a go at.

i think you should put a few questions up as i like to see questions and stuff where we have to use the knowledge we are learning at college to answer them