thread238-374459
I have a similar case with a Dyn11 33/0.415 KV transformer connected reverse fed to a LV Switchboard which totalizes 4 LV Gens onto the same bus.
What is the best and safest earthing scheme that has to be adopted?
Yes Waross you are correct the inrush current will be reduced as the gen ramps up voltage.
But since I have 3 transformers to energize I am thinking of time delayed magnetization..
Hello waross
Thanks for the tips.
Unequal Voltages and Phase Angles are unlikely because all transformers will be fed from the same bus and at the same time they have identical parameters.
Anyway, I do appreciate your comments.
Good morning waross,
Thanks for your comments.
So generally speaking the design is acceptable and no need to introduce any changes.
I am a bit worried about the reverse feeding of the step down transformers (to step voltage up).
As a matter of fact all the suppliers here in Nigeria are against...
Thanks maghawe,
Yes, my transformers are identical 33/0.415 KV Dyn11 Step down (connected in reverse feed mode).
I intend to keep the transformer feeder breakers closed. These will provide upstream protection for each feeder.
The controlled breakers are the 4 incoming breakers on the LV...
Thanks Iceworm,
The comments I meant to receive are related to the choice of step up transformer and if it would work fine.
The generators will be solidly grounded.
The step up transformers will be off the shelf Dyn11 (originally designed as step down)connected in reverse feed mode (star on LV...
Hello guys,
Sorry for posting a late reply to this thread.
I have a similar project like Maghawe's.
In my design there is NO paralleling with Mains.
I have 4 generators synchronized at LV (400 Volts)then Voltage will be stepped up to 33 KV.
The SLD is similar to what Maghawe had posted but our...
As explained the Synchronization of 4 generators will be on the LV side.
Then we need to step up the voltage to 33 KV.
In the absence of an step up transformer, we are planning to use a step down transformer and connect backwards to step up the voltage.
However, we are trying to study the...
Good morning,
I have a Synchronization Panel connecting 4 generators together (415 Volts) onto the same bus.
After the bus we are going to step the voltage up to 33 KV.
Is it advisable to use a step down transformer and reverse connect (for step up)?
What kind of Neutral grounding has to be adopted?