Heeeellpp!!!!

[tuckerkop81]

Gents, in need of your experience/knowledge.

Im working in maintenance at a student accommodation. ( over 900 rooms, over 60 boards )

The buildings need their periodic inspection and testing.

Im trying to be as less disruptive as possible so am just turning the circuits off under test. However, im finding this really uncomfortable, what with the arching and cpcs squeezed behing the line cables. I have asked permission to turn the board off, but this isnt really an option as the rooms all have fridges in and the students are forever studying. My question, can i obtain R1 + R2 by taking my highest Zs reading, calling the Elec board up and getting a true reading of Ze, and making a calculation. I just cant see how this would be good enough to put on a cert as the board will only give me a Ze from the intake room for starters. Plus the fact Zs will have parallel paths. Before i get abused, yes i have my 2395, although my experience in testing is limited. ( Thrown in at the deepend )

Thanks guys.

Tom

 

[DPG]

It shouldn't do any harm to the fridges to knock the power off for a couple of hours per board. Food stays cold for hours. Daz

 

[Darkwood]

The students have been warned, you have permission just switch off and do the necessary, as above also if the fridge is shut its a good 4hrs before temp' rise is a worry ..... think you're trying to be too accomodating here ..not a bad trait but with that number of flats you need to establish a good routine and repeat without all this trying to avoid disruption ...I see you lose multiple flats if you switch off a board - in this case section the boards and do them in quarters and have a helper so you can race through the testing together.

Do we have 15 flats per Sub main then?

 

[tuckerkop81]

So in each board i have 13 power and 13 lighting circuits. Each circuit feeds 2 rooms. So 26 rooms per sub board. Yeah ill have to just gain permissio to turn the board off, i was hoping theyd be an easier way by calculating but thats being lazy. thanks guys for confirming.

 

[davesparks]

The only way you will get an accurate Ze is by measurement, which means isolating the whole installation and isolating the earth. However to backwards calculate you would need Zdb which is the Zs of the submain feeding the board.
What is acceptable for radials is to use a wander lead to test R2 for each circuit, although this wouldn't prove polarity unlike the R1+R2 test

 

[stevey1983]

Just turn it off, tell them the more they moan the longer it will be off. Power of being a sparky. Fridge is fine for 24hrs so long as you dont open them and most people use laptops nowadays. Always put your own saftey first, if your not happy working on a live board, dont. You only have 1 life but you can always get another job

 

[jimjimjim]

I've seen the outcome of someone being pressured into working on a live board. Outcome being a hole burnt through his hand.

It's fine to use Zs as your R1+R2 reading as per GN3.

Jim

 

[Deleted member 9648]

For an EICR it is not generally necessary to test R1+R2,that test is really intended for initial verification on a circuit prior to energising.What an EICR is really concerned with is adequacy of earthing and disconnection times. In order to minimise disruption carry out Zs tests on each circuit,as long as they are good and as expected then it is reasonable to assume satisfactory R1+R2. It helps if the original EIC is available as then Zs test results can be compared and if they are ballpark close then again,it is reasonable to assume satisfactory R1+R2. You will still have to isolate the entire DB in order to carry out IR tests. This is best done once all circuits have been inspected and Zs tested,and then a global test can be carried out in a very short time with minimum disruption.
There will be those who will throw their toys out of the pram at a practical approach to EICR's. But in my experience they are keyboard warriors who have never actually carried out an EICR in a real world situation where major disruption is not viable and cost and time IS a consideration.

 

[Corbs]

you still have to think about the computers tho (hope no wannabe law students there)

 

[telectrix]

the silly buggers willl have to stop playing internet games for a short while when the wi-fi goes down.

 

[tuckerkop81]

Thanks so much feveryone's input.

 

[shanky887614]

the silly buggers willl have to stop playing internet games for a short while when the wi-fi goes down.

the smart ones will use there phones anyway.the rest well can read a book lol

 

[telectrix]

yeah, coz daddy's a lawyer/accountant/doctor and has provided them with a contract smartphone, tax deductible.

 

[Corbs]

yeah, coz daddy's a lawyer/accountant/doctor and has provided them with a contract smartphone, tax deductible.

but doesn't stop them compiling to daddy and getting daddy to write a formal letter to ask why the wifi/power went off

 

[telectrix]

sod 'em anyway. students are animals.