Filling in test resullts for 3 Phase/which Zs?

[Piratepete]

Hi Guys

I've just completed my first 3 phase installation. A 3 phase CU (Proteus) in a church extension. There are 12 x 230V circuits feeding sockets , lights, heaters, etc.

1. Do you record all circuit test results on the same page or use one page for each phase?

2. Do you record Zs at DB and Ipf at DB for each phase or just the worst values?

3. Is any extra signage required e.g. to identify which phase used on accessories? I have put a 415V warning sticker on the CU

Cheers!
Pete

 

[ChrisElectrical88]

Take the sticker off and stick a 400v one on ;-)

 

[telectrix]

1. record all on 1 sotr. but note which phase each is on.

2.measure Ze for each phase and record highest (if any,they should all be equal). PSCC measured phase-N and x 1.732.

3. if there's 415V there, then leave the 415V sticker on. sod theoretical, non-existent values. and while i'm here, SOD THE EU.

 

[davethsparky]

Down with the eu!

 

[guest119]

I never liked sprouts.
Like them even less now.

Boydy

 

[Risteard]

Take the sticker off and stick a 400v one on ;-)

And then take that sticker off too because Uo does not exceed 230V!

 

[telectrix]

cobblers. if there's a PD of 415V between any 2 points, then that's the value that should be on the sticker.

 

[shagbite]

the nominal value of voltage between phase and earth (Uo) is 230v - whether it's single or 3 phase.

415v would be the nominal voltage (U) between 2 phases.

 

[trev]

Question 3, I like to see identifiers on accessories to show which phase and breaker they are fed from. Makes it easier to figure out what is on which circuit, knock that one off, safe iso and away you go.

 

[johnboy6083]

I agree that stickers showing 400V are often not needed. the requirement is for a warning label for anything with a Uo of greater than 230, which for 90% of us electricians is no. Only once have I come across a 690V system, and I wasn't working on it! HV systems don't come under BS7671.

 

[telectrix]

514.10.1. ".........warning of maximum voltage present is clearly visible". that max. voltage within a 3 phase enclosure is the voltage between 2 phases. i.e 415V.

 

[netblindpaul]

Tel,

The "full" reg is as follows:

514.10.1
"Every item of equipment or enclosure within which a nominal voltage exceeding 230 volts to earth exists and where the presence of such a voltage would not normally be expected, shall be so arranged that before access is gained to a live part, a warning of the maximum voltage present is clearly visible."

This is a direct copy & paste from the latest official IET electronic regs, I have not highlighted anything, but, from this reg it can be seen that there is in fact no requirement for a 400V warning sticker as in a 3ph board, whilst there is 400V between phases, there is still only 230 to earth.

Do I fit "Warning 400V" stickers, yes I do!

On control panels I often put 400, 230 & 110 labels to warn of the fact there are mixed voltages in them.

 

[telectrix]

agreed, paul. i misread it. obviously, according to 514.10.1, if the nominal voltage to earth is not > 230V, there's no need for a warning label. however, how many times might you find 2 phases in a switch box in an industrial site? not to fit a warning is, IMO, crazy. i contend that this is one area where BS7671 and common sense diverge.

 

[Flanders]

You often get a 400 volt warning label with the grid plates but this can be put this on the yoke instead on the front plate so it don't look a mess on a chrome front plate. I have always thought it was a requirement if there was 400 volts between phases so will look at the bgb tomorrow


Yes that's an interesting Reg might show Mr NIC inspector on his next visit as he is always pulling me up on no voltage warning labels missing

 

[Amp David]

Take the sticker off and stick a 400v one on ;-)

And then take that one cos you don't need it.

And its a DB not a CU