The busbars are air cooled but not forced ac, just a natural air circulation. The phase current is 16818 A at 78.01 V, there are 13 taps (78.01 V to 164.18 V)
Yes, the idea is very expensive and impractical if not unfeasible/imposible at all !
Once more I appreciate your comments, as usual...
Thank you guys for the replays;
warros:
The basbars are 10"x7/16" HCC, 8 per phase
Do not have the impedance or VD of the busbars.
We have not recorded any problem with circulating currents .
I agree the voltage drop would be an issue and that will create problem with the furnace...
Could someone help me with the following:
We have two 6 MVA 11kV/78.01V AC/AC Dd0 furnace transformers, feeding two sets of the furnace electrodes.
Our operations want to move the transformer away from the furnac for safety reason (fire etc).
The furnace electrodes are in delta configurations...
Unless you corrected the schematic you have posted on the web quoted above , it is wrong.
You have excellent advice here from people :
1 One neutral only
2 Design Earthing/Ground system separately
3 Design neutral system
4 Position of CT and type of protection is important if you do not want...
I know you've said you do not want any more emails, so please do not feel under obligation to replay.
I was on holidays and missed the whole discussion :-)
Apologies to jbartos, electricpete,dougmsoe, gsimson if I repeate what you have already said; you guys provided v.good replays...
There are two issues which may cause/contribute to the problem you've described;
1) system grounding - the medium voltage systems (2.4 to 15 kV) should not be solidly grounded because high e/fault currents may damage the rotating machinery; Also, It should not be ungrounded because it would be...
The system is correctly grounded. Just draw a zero sequence diagram and you will see the flow of earth fault = 3xzero sequence current in the system.
There are of course other schemes but they would be more expensive and complicated in operation.
Solid grounding is used for low and transmission...
The zig-zag is for grounding purposes and to allow earth fault detection.
The generators are high resistance grounded to limit third harmonic currents which are same as zero sequence current.
Even if the generators are identical there is possibility of 3rd harmonic circulating current being...
Stevenal wrote : - I fail to see where he (artym) suggested this "The start current of a motor is dependant of a motor driven load."
I agree, my apologies artym, I've jumped to conclusions :-)
Let remind ourselves the basics, since we went a bit off track and some suggestions are not correct: :-)
(By the way fully agree with scottyUK and rbulsara)
The commonly held misconception about motor starting is that:
The start current of a motor is dependant of a motor driven load. (artym)...
Thanks for comments bulsara , re. point 2 fully agree :-))
re. point 1 I have not heard of inserting resisitors in the rotor winding after a motor has been made and is in service, if that's what you mean ???.
On our sites we have both, star and delta connected rotors, all in the range of 2.5...
rbulsara
skippywest question has nothing to do with the star/delta starting, the Q is " the pros and cons of STAR OR DELTA CONNECTED ROTORS FOR THE REPLACEMENT MOTORS "
I now that:
Majority of rotors of SR motors are connected in star
Delat connection is probably cheeper
Has to...
