Confused About Lost Phase

[wsoppitt]

Had to go and find out why a local garage had lost all power .

Tested between 3 phases at service meter and nothing on L1 , 415v on L2 and L3 ,230v between L2 / N and L3/N . so came to conclusion that phase lost on supply side.

What im confused by is that obviously some of the installation will be single phase ( office , reception , etc ) so why was power lost on 1 phase affected the whole installation , thought the single phase circuits would still be ok.

Not really had much 3 phase experience.

any help would be great as i told owner of building to contact supplier as phase lost , but now i think i may have missed something .

 

[SLIPSHOD & SLAPDASH]

Your correct, so I would guess no single phase circuits on the lost phase

Edit, miss read your post. I am going to guess a contactor fed from the lost phase, sometimes a last man out switch

 

[Dagrat]

as above.

would imagine the single phase circuits are all taken from L1  assuming only lighting and power circuits

 

[kerching]

Where actually did you test for voltage?

My money is on a bad design where ALL control circuits AND all single phase circuits are fed from L1, which is pprobably why the L1 fuse has lifted due to overload.

Why do people insist on all control circuits go,on Red along with most single phase circuits??

Just curious

 

[batty]

5WW because L1 is the live one

 

[wsoppitt]

5WW because L1 is the live one

who you refering to as 5ww ?

 

[SLIPSHOD & SLAPDASH]

who you refering to as 5ww ?

Ignore him, have you been back or found out more ?

 

[batty]

who you refering to as 5ww ?

It was a joke kerching asked why  people put control circuits and single phase circuits on L1  I said as a joke they are 5WW because they think L1 is the live one.