First ever commercial periodic - help!

[sparky05084]

Hey all.

Not been on here for a while and I have been doing a bit of browsing in this section to see if anyone is in a similar situation but not really.

Anyways, so I’m going to be performing my first full periodic inspection report and of course testing at the weekend and I could do with some advise just to give me peace of mind and help give me a lil confidence boost (I believe I’m a good spark but sometimes need reassuring lol).

The environment is a small commercial/light industrial unit, like a machine fitting shop if you like. 3 phase supply, TNC-S system feeding a 3 phase board with final circuits (60898 and 61009s) and a 63A sub feed to office block which in turn has its own consumer unit (RCD protected 30mA with 100A main switch and again final circuits - protected by 60898's).

Hope the above isn't confusing - please ask me if it doesn't make sense. Now, I actually did some installation work there (supplied power and fitted a 3 phase/neutral and CPC socket) and now he wants me to test the whole site as the periodic has expired (5 years I believe for commercial/industrial).

Noticed that the main gas hasn't been bonded so prior to doing that I will bond it as I’m sure you would agree why do a PIR only to fail it as no bond to gas is a no no and would defo be a code 1 in my mind.

Structural steel work and water bonded so no worries there. Asked the customer if it was ok to view previous PIR paper work to which he happily obliged. On viewing it I saw that there were no major issues other than workshop sockets have no RCD protection (this was down as a recommendation but I have no idea why gas wasn't bonded how the hell did it pass?!)

I have gotten around this by putting in RCBO's so essentially the shop floor has RCD protection now. Now, here is where I am a bit stuck. I want to impress this guy as he will be present whilst I am testing and he has promised me future work. I am pretty comfortable with the testing procedure but one thing is bugging me. In the paperwork it mentioned (can't remember where like but something along the lines of "lighting circuits IR tested with all switches left in the off position").

The lights are basically twin fluorescent fittings (big buggers they are I think 8ft). Now, I am quite happy to take the time to remove all the lamps as I know that doing an IR test with lamps still intact is not healthy and will give bum reading and can damage vulnerable equipment.

My question is this - if I removed all the lamps from the fittings and IR at the board with the switch on will I risk buggering the fittings up? Will it damage the ballasts and stuff?

I don't want to have to tell the customer that I’ve blown his 12 light fittings

He is quite on the ball and told me that if the last IR test was indeed performed with the switches in the off position incl two way setup then the switch wires to the lights (conduit wiring setup) have been omitted form the test and thus have not been tested at all and he wants me to be thorough.

What advise would you give me and would it be safe to test the fittings? What have you done when in this situation?

Many thanks for reading sorry for the waffle J

Sparky05084

 

[Deleted member 9648]

Personally I rarely IR test L-N on a periodic as even if you take the lamps out you will put 500v across any H/F ballasts etc.
Just leave the lamps in, and test L/N- earth only with all switches closed.....easy,perfectly acceptable and you cant fry anything......note on the cert that L-N IR tests not carried out due to risk of damage to connected equipment.

 

[Spudnik]

No reason why you cant leave the switch off, however, you could always just do L/N to earth IR and note on the cert.

Typing toooooo slow again.

WP beat me to it

 

[Deleted member 9648]

And lil old me a one fingered typer as well!!!
I once fried a franking machine doing a L-N IR test on a periodic mistakenly thinking I had everything disconnected, a vast quantity of bull droppings was needed to get out of that one. Now I'd only ever do it on a new circuit where I am certain exactly what is connected,...just not worth the risk.

 

[Spudnik]

And lil old me a one fingered typer as well!!!

Yeah but i was eating a packet of crisps

 

[sparky05084]

Cheers guys for the quick response. What flavour crisps? lol.

So, basically this may sound daft and forgive me if its a school boy question but do you simply mean test at the CU on the lighting circuit between L/N on one lead and then CPC on the other with switch in "off" position?

Am I missing something or do I leave lamps intact, put switch in "on" position and test between L/N and CPC at source?? Where do I put it on cert if indeed thats the test procedure I take? Arrrggghhh Im confused now

 

[Des 56]

You either disconnect this that and the other and test where application of test voltage wont affect electronic equipment or you can test lines and neutral to protective earth ( so in order not to damage the installation,unless you are absolutely confident all is dis connected, test to earth only, with links on )

You have to ensure that there are warnings on the dist boards stating insulation tests can damage blah blah


At the final circuit distribution board,between lines and neutral connected together and earth
Then at main and sub main distribution boards with the final circuit distribution boards isolated

At the final circuit dist board,with the lines and neutral connected and testing to earth,it doesn't matter whether the switches are on or off,as the test to earth would be applied because the line and neutral are connected together and the position of the switch makes no difference.(only need to switch the two ways)

In the limitations box state the insulation tests carried out and why

The Gas bond would be code 2

 

[Baal]

Beg, borrow or steal IEE Guidance Note 3 and the ESC Best Practice Guide No 4-free download from http://www.esc.org.uk/pdfs/business-and-community/electrical-industry/BPG4_08.pdf

Also, maybe invest in some indemnity insurance if you intend to undertake regular periodic inspections-I assume you have C&G 2391.

Take your time, be thorough and you'll probably find 90% of your defects through inspection rather than the testing process.

Put the PIR into a hard file with the clients name printed on the front and a brief overview at the start, just describing the installation generally and expanding on any areas of concern.

Depending on what the job is worth, you can expand the file to include images of DB's, DB schedules, RCBO quarterly test sheets, fixed appliance tests, PAT, etc etc

 

[Risteard]

I once fried a franking machine doing a L-N IR test on a periodic mistakenly thinking I had everything disconnected, a vast quantity of bull droppings was needed to get out of that one.

Nice going! I once thought I'd blown a TV up in an old folks home when they said it wasn't working. Luckily I realised that I'd disconnected it earlier and they just hadn't plugged it back in. Quite a relief...

 

[SEC-Tom]

Great topic this, has really helped me out a lot too.

 

[buttonmoon]

I know this is a little late but couldn't you just test at 250v if the client wants you to be thorough but it isn't reasonably practicable to dismantle each fitting. Still min 1 Mohm though.

I think I read that somewhere NIC stuff perhaps.

 

[buttonmoon]

Found it! 612.3.2 below table 61 BRB