415v ~ in your house?

[theroadblock]

Heres one for you guys, not sure if you've ever given it a thought but an operator at my workplace today mentioned that he keeps having power dips / losses to every other house in his street, so obv i thought 'ok there is probably some issue with one of phases supplying your area'. anyway so he confirms this by telling me his nextdoor neighbor still has power when this occurs, andso, he went and did the dreaded and now has a.. wait for it... socket outlet in his house that is supplied from nextdoors supply (with their permission ofcourse...). now apart from the obvious things wrong with doing such a thing, surely there is the potential of 415v should a fault possibly occur between the two houses.. scary stuff... mg_smile:

 

[Darkwood]

Just remember 230v kills 400v kills......

Liken it to been run over by a bus whether it be single decker or double decker you are at serious risk of death or injury regardless of the size of the bus..... and at these voltages its a similar analogy.

 

[odawire]

caus theres only one way being used on it...trust me..i took the pic...
and no, it wasn`t a shared supply or anything like that....

Ah u mean the picture, beg your pardon, thought you meant the light switch scenario

 

[GLENNSPARK]

yep...theres this popular misconception that if its 3 phase..watch out but if its single phase...then somehow its not too bad.....complete cobblers...
last time i looked it was anything above 50V....with enough current that is...

 

[GLENNSPARK]

Ah u mean the picture, beg your pardon, thought you meant the light switch scenario

sorry about that one....like theres 2 different sub topics going on here...lol...

 

[R G]

yea, you need to have a "danger 415 volts" sticker on the out let which is way you would avoid it because it looks ugly, however if your using a separate front plate type plate you can put it under the plate, before the screw off plate.

edit: yes as darkwood says 400v now

I cant say I have used a light switch in this way....I would have to put a 400v label alongside the switch , but cant think of anybody wanting this in their house

 

[theroadblock]

when i said the neighbor is ok with it, they decided between them to do it so i was being serious lol. and no i havent physically seen the socket outlet, but i know for a fact that he said hes put it next to his own socket outlet for his tv, ( got his priorities right in the event of a powercut i see...).
as for the warning labels ect, we have those at my workplace in the production area as the lighting is alternated over the 3 phases to avoid stroboscopic effects, but i doubt very much this guy knows that haha!

 

[odawire]

I cant say I have used a light switch in this way....I would have to put a 400v label alongside the switch , but cant think of anybody wanting this in their house

Yea its not my preferred method, but ive seen it a few times, usually when theres been an electrical designer involved, and they haven't thought about about the balanced phases coming together in a two way switch, doesn't make any difference to the final outcome other than the label

 

[Darkwood]

In domestic you take this into account in circuit design and avoid the need to have 2phases within the same switch, its not such an issue in factories etc with metal clad switches and small discreet 400v warnings .... larger install tend not to have this issue as control circuits usually pull in lighting contactors which are housed elsewhere.

 

[ian.settle1]

This topic is often asked from domestic sparkies but 3ph IS common in commercial and industrial to be found as already posted in switches etc and been in close proximity in outlets like commercial kitchens etc and all the regs specify on this is appropriate warning labels are present if voltages exceeding 230v are found where not expected or between adjacent outlets that can be both reached similtaneously.

Can you quote the reg number which states this please?

 

[KAS1]

I have a three phase 100A supply to my house, nothing wrong with that at all, feeds three separate dis boards and all is well. lol mind you I do have a rather big house 9 bedrooms at the last count lol

 

[bertt]

Hi,

I don’t know how it looks the propriety.
I don’t think you got the voltages as 415V on AC (not DC) scales measurement and up to 600V. I saw the picture about supply you added it as well.
If it is lighting circuit …no way.

But, for lighting circuit any capacitor energized, could bring the voltage, without load, roughly from 230V to 325V. I mean capacitor for Power Factor Correction (cosφ) from inside the lamp. (u = Uef * 1.41*cosφ ; u = 230*1.41*1= 324.3V). About electric motors it is close.


Please tell me the value of voltage immediately after 100A FUSE. Thank you.

I look forward hearing from you.

bertt.

 

[KAS1]

what the ...... is this all about

 

[Guest55]

Its 400v now when discussing but apart from that minor point as long as 2 power points can't be reached similtaneously then no issue if they can then a clear warning label needs to be affixed regarding the 400v that exists between the 2 points.

i dont really go with that,
just because 2 sockets on different phases can be touched simultaniously doesnt constitute a hazard in itself , and the use of 400v stickers is inaccurate when the max voltage at each accessory is 230.
where would you put the 400 stickers ? on the wall halfway between ?

 

[Robson689]

i dont really go with that,
just because 2 sockets on different phases can be touched simultaniously doesnt constitute a hazard in itself , and the use of 400v stickers is inaccurate when the max voltage at each accessory is 230.
where would you put the 400 stickers ? on the wall halfway between ?

Yes with big arrows pointing to each socket either side of the sticker!

 

[Darkwood]

i dont really go with that,
just because 2 sockets on different phases can be touched simultaniously doesnt constitute a hazard in itself , and the use of 400v stickers is inaccurate when the max voltage at each accessory is 230.
where would you put the 400 stickers ? on the wall halfway between ?

Interesting reply because its a regulation not an opinion.... its rare in houses and you design to avoid the situe but i do more commercial and industrial i use a pro' label machine and can fit either caution 400v!....... or even caution 400v exists between adjacent power points on or next to each point when required.

commercial kitchens have this set-up alot to balance the heavy 1ph loads over the phases

514.10.1

Im only quoting regulations not a personal opinion... in my mind only a competent person should be accessing these points and if they follow testing procedures then they would be aware of what voltage existed but this dosn't happen . Its only for points enclosures etc that wouldn't normally be expected to have 400v so a 3ph socket wouldn't require such marking only say a switch bank where numerous supplies exist over phases.

If you dont want unsightly stickers dont design the install as such to require the need to comply to this reg.