Strange Electric meter

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tek9

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Australia
My girl went out to buy a new car for me,after totalling my brand new caddy,ran into a garbage truck at 60mph whilst texting her friend about Justin Beiber,they went to an old junk shop and bought this old electricity meter with a lot of german writing,all I saw was 3phase 410v 16 2/3 hz,where was that used?The garbagemen joked,we'll crush that pile of junk for you if you like.All I could say was,I wish Beiber would get eaten by a leopard or something.
 

tek9

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Location
Australia
Marky the sparky,from an old edition of the Australian Wiring Rules,''IN factorys wired with the American corner earthed delta,one phase C,shall be earthed before the current transformers,after the meter board,it shall be labelled as B phase,also if using this system with a motor converter,and one phase is earthed,it shall be grounded at the nearest water pipe by a cable no smaller than 000 AWG,also the ground phase shall be white,however it may be black,that guy must have drunk a lot of beer before writing that,b becomes c,why?
 

K8MHZ

Senior Member
Location
Michigan. It's a beautiful peninsula, I've looked
Occupation
Electrician
Marky the sparky,from an old edition of the Australian Wiring Rules,''IN factorys wired with the American corner earthed delta,one phase C,shall be earthed before the current transformers,after the meter board,it shall be labelled as B phase,also if using this system with a motor converter,and one phase is earthed,it shall be grounded at the nearest water pipe by a cable no smaller than 000 AWG,also the ground phase shall be white,however it may be black,that guy must have drunk a lot of beer before writing that,b becomes c,why?

Sounds like C becomes B.

But if A stays A, then B will have to become C anyway, and you would be correct.

But if C becomes B, and B becomes A and A becomes C, then not so.

The shall be white but may be black is weird.
 

hurk27

Senior Member
In all 5 jaw meters I have ever installed the grounded phase was always landed in the meter on the C lug which is the small fifth jaw in the middle of the other 4 jaws, the meter only needs the voltage from this jaw which is why it is smaller, but when we bring in these three conductors the C leg is landed on B phase in the panel or the neutral bar which is why it is required to be white as well as all grounding and bonding is connected to it, most grounded B panels will only be a two pole panel similar to a single phase panel, but since the voltage to ground is 240 volts you must use 240 volt rated breakers.

Also to maintain the correct rotation you will have to rotate A to C and the C to A if they grounded the C phase at the transformer, if B is grounded at the transformer and just remarked as C in the meter then you keep the same rotation at the panel, but I have found it both ways.

Grounded B services can confuse many who are not experienced with them, I have had many calls over the years from HVAC contractors who thought they had lost a phase because they would read 0 volts to ground on one of there compressor feeds, I just ask them if they have 240 volt to ground on the other two and if they say yes I tell them they have a grounded B service and they still have 3-phase.
 
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