hi briand, most xlpe failures are down to poor termination of the semi conductive layer.
the semicon layer needs to be removed with special care and use of correct tooling .
whats the history of the cable ?
had motor guy in on thursday,the two rotor windings checked
ok as did stator.
motor has been starting ok since I increased start up timer
but still only reaches 690 rpm before pulling in so iam now going to really look closer at lrs as I assume if rotor
ok lrs limit final speed befor synch...
is protodur a trade name?
i not heard of protodur,is it a
plastic,rubber or paper insulation and what type of screening does it use?
when you contact a contractor it would be usefull to
have a sample so that a suitable joint can be found
hi vanskat ,procedure for jointing/splicing of hv cables will depend on the type of cable how/ it is installed
lets have some details , eg,paper/lead/xlpe/epr
above or below ground,why it failed etc
many thanks to all for your input,i now have a list of
things to check when the specialist motor guy comes on thursday.
still waiting for original lrs spec however an operatve says aguy from the starter makers drained refilled the lrs
need to speak with him soon.
increased timers but found that motor speed would not go above 700rpm until changing to dc
when the rotor is being tested i should be able to compare
the resistors to makers spec
by the way when the drive was new would the lrs have allowed the motor to get that close to synchronous speed?
the motor in question is as dopler shows lrs then two rings shorted with dc to pull in,on load start
rotor and exciter being tested on thursday as i have had tacho on shaft at start up and it only got to 600 rpm befor dc applied.
changed timers and got to 700rpm,big improvement but still fails...
many thanks eddison.
I measured run up times of the outher drive [witch is fine]
and this made it to 690 rpm [60rpm short of 750 rated]
before it changed to dc control;this machine seems to stay in it's accelleration stage for longer than the problem drive,i cannot turn it off for four days as...
new boy here,hope someone could help with a problem thats got our team stumped!
motor runs a ball mill,motor runs up fine thru first and second stage resistances but nine times out of ten hunts badly with large current swings after shorting of rotor resistances and changing to exciter control...
