Advice for minor works

[ianb89]

Hi to all!

Some advice please....

I am newly qualified sparky and i have just set up my own business and already been offered to do a loft conversion and an extention, which i haven't quoted for yet.

Before i set up i was a house basher so not much experience doing this kinda work

So this loft conversion requires extending the ring and lighting circuit. Would it be best to do a quick loop test on these 2 circuits?...to make sure that i'm not extending a circuit which could have a broken earth which would make testing at the end of the job a nightmare?

This of an obv question really but i want to know what other electricians do as i don't have experience doing minor works.

Thanks in advance.

 

[Paul.M]

Ian it sounds like your biting off more than you can chew for your first project. Loft conversion in my book = put a small 2 or 3 way dis board in the loft to keep it separate from the other house circuits and for safe isolation in the future. Work out the max demand for the loft (using diversity calcs) and feed it from its own supply, don't tap into the ring to feed it.

If your unsure about doing this job pass it on to someone that has more experience and ask to work with them to learn. BTW its not a minor works cert if you install new circuits.

 

[Paul.M]

Another thing, check with your local building control officer regarding smoke/heat detectors for this extension.

 

[jase]

if you are going to alter or extend an existing circuit then it is indeed a minor works, nothing wrong with extending the circuits, i would even go so far as to say you could spur off the existing to a FCU and run a radial round the loft with another FCU fused down to 3A for the lights, really does depend on supply characteristics and the intended load, RCD protection would be required to any new wiring depending on the wiring method used, and you would need to check the adequacy of the earthing.

 

[GLENNSPARK]

Hi to all!

Some advice please....

I am newly qualified sparky and i have just set up my own business and already been offered to do a loft conversion and an extention, which i haven't quoted for yet.

Before i set up i was a house basher so not much experience doing this kinda work

So this loft conversion requires extending the ring and lighting circuit. Would it be best to do a quick loop test on these 2 circuits?...to make sure that i'm not extending a circuit which could have a broken earth which would make testing at the end of the job a nightmare?

This of an obv question really but i want to know what other electricians do as i don't have experience doing minor works.

Thanks in advance.

perhaps you should take a look at a minor works cert and you will see part 3 which deals with ESSENTIAL TESTS.....and whats the first on there eh?......earth continuity...and the second deals with IR....thats before you get to loop....so if you were to break into a ring then you cant "just do a quick loop test" as you suggest....and as paul....separate cu for this and if you dont know how to apply diversity to connected loads and CUs...then look in the on site guide....its all in there.......

 

[gottahugenoggin]

Hi and welcome
Im still in college,but id like to think when im out there id do all the tests required on the minor works cert.
Maybe this seems OTT and impractical but at least you'll find out exactly what your dealing with and quote accordingly.
I mean you could carry out the work,only to find it not up to par on any one of the tests,which will have to be rectified to sign it off.....it may take longer in the first place but could save you an awful lot of head ache in the end.
Thats only my opinion and i may get told otherwise.
regards.....Dave

 

[jase]

Loft conversion circuits

 

[jase]

perhaps you should take a look at a minor works cert and you will see part 3 which deals with ESSENTIAL TESTS.....and whats the first on there eh?......earth continuity...and the second deals with IR....thats before you get to loop....so if you were to break into a ring then you cant "just do a quick loop test" as you suggest.

I think the OP meant before he broke into the ring to check that the ring is ok to do so

 

[Paul.M]

Nothing wrong with what you've said jase but separation of circuits (im different floors) springs to mind. 1st floor mcb trips out the bedroom floor and the loft, then you have to go down 2 flights of stairs in the dark to reset the mcb?

 

[Bigboy247]

I have done loads of these, check with building control as they all make it up as they go along. Go up through the box room above the board downstairs (just an example) throw in a 1.5 T& E for loft lighting, 2.5 T&E x2 for the RFC for loft sockets. A cable for interlinked smoke alarms. Depends on the existing board add,replace or split tails and a small rcd protected unit. If you're Part P registered you know the next step, if not contact building control at least two weeks before and tell them then inform when complete pay your fee and they will send someone out to test and sign it off.

 

[jase]

upstairs power side trips you only got to go down one flight of stairs to get to the upstairs landing, where the upstairs lights will be on cos they should be on a different side of the board to the upstairs power, you probably wont have any lights downstairs but thats ok cos you should have sockets downstairs for table lamps as the downstairs sockets would be on the other side to the upstairs sockets, upstairs lighting side trips thats fine loft would have light due to being wired on upstairs power althought you wont have any light upstairs you will have light downstairs to get from upstairs to downstairs

 

[Paul.M]

Post deleted and a pm sent to Jase apologizing for posting up a sarcastic remark. He didn't deserve it. Funny but didn't deserve it.

 

[GLENNSPARK]

upstairs power side trips you only got to go down one flight of stairs to get to the upstairs landing, where the upstairs lights will be on cos they should be on a different side of the board to the upstairs power, you probably wont have any lights downstairs but thats ok cos you should have sockets downstairs for table lamps as the downstairs sockets would be on the other side to the upstairs sockets, upstairs lighting side trips thats fine loft would have light due to being wired on upstairs power althought you wont have any light upstairs you will have light downstairs to get from upstairs to downstairs

all very well but as the upstairs landing light (2 way) will be fed from the downstairs lighting circuit...this would mean that you have to go down 2 flights of stairs....in the dark and given the fact that loft ladders/stairs can be steep n all.......

 

[jase]

hallway on downstairs, landing on upstairs, 2g 2w switch on each floor

 

[jase]

that is why on a 2 storey house you put one on one side and one on the other so that there is always light on or around stairs if either side trips

 

[Paul.M]

Back to the ops question, would you tap into the existing ring and lighting circuit or install a db2?

 

[GLENNSPARK]

that is why on a 2 storey house you put one on one side and one on the other so that there is always light on or around stairs if either side trips

ok Jase but i still think that pauls way of using a sub board is better as you have the diversity and you will need to ensure that you have 10% spare ways on the main c/u...so what if its fully loaded up then?.....and before you start about RCBOs then that would mean a high integrity board for the mainc/u and as you probably would find its a split load at best you would have to change it.....and thus would be inspecting and testing the whole install again....which may throw up other problems/issues that you can do without.....

 

[jase]

well that would be up to him, as for testing the existing ring to ee if it would be worth tapping into then by rights yes, would be worth doing IR R1+R2 and loop test before hand to see if it is suitable, you would also need to check the adequacy of the earthing and to make sure that any new wiring is covered by an RCD if required

 

[Paul.M]

We could do it either way, after all its only going to be a few sockets and two lights unless the customer puts in a bathroom with a shower.

Think the op needs to give us more info on what the customer wants to have installed.

On a personal note, i dont like tapping into existing circuits for loft conversions. Put it on its own db and everyone is happy. Well I am anyways .

 

[GLENNSPARK]

well that would be up to him, as for testing the existing ring to ee if it would be worth tapping into then by rights yes, would be worth doing IR R1+R2 and loop test before hand to see if it is suitable, you would also need to check the adequacy of the earthing and to make sure that any new wiring is covered by an RCD if required

well i know i would feel better if i had performed these tests and had some values i could note.....covering yourself and you should prove by both inspection and test that circuit/s that you either add to and/or alter are good for continued service and that anything you have done to those circuit/s is not going to have a detremental effect......