Quote:
Originally Posted by charlie  Have got my practical soon can anybody help.
Have been told there is a 3 phase starter + socket, is it o.k. to measure R2 for continuity of c.p.c. and when Zs is required to measure ( by using a plug and lead ) it at the socket ?? |
Hi Charlie
basically no - GN3 says that motor circuits (which this is) then the loop imepodence is ONLY measured at the supply side of isolated motor control gear.
Do R1+R2 checks on the three phase supply to the contactor, and again on the other side to the socket.
Then either calculate Zs = Ze + (R1+R2)+(R1+R2)
or add the additional socket side R1+R2 to the measured Zs.
And rememebr, you ONLY have to measure Zs at the socket outlets, C&G state for all other points, measure or calculate.