Hi guys,
Can anyone explain to me the differences of FCC and RFCC?
What's the difference in feedstock and typical yields composite of various petroleum products (LPG, gasoline, naphtha, gasoil, etc)?
Thanks.
Hi guys,
How easy is it for power generators to switch between different feed? Example. Can a generator running on oil today be running on natural gas tomorrow? If yes, is it true that most large power plants have such generators that can switch fuel easily?
Thanks.
sorry,
As the event was deleted by someone, I couldn't get the ground fault values in time. This is a synchronous motor.
Now, we may assume it as a fault at the bushing and assume that the current in the secondary CTs are due to motor contribution.
However, what's the significance of the...
rbulsara
Red and yellow bushings porcelain craked. PT cables and fuses burnt.
51G picked up. 87T picked up.
The transformer is a captive transformer running only 1 14000HP motor.
Motor was running for many days before failure.
Transformer windings, CT and PTs were not damaged. Motor meggar...
stevenal,
there isn't any previous failures before.
However, I checked some sites saying that typically motor contribution is about 4 times the running current. My motor is running at >900A. Thus, I think the readings at the secondary CT might be only motor contribution and there could only...
I think the CT saturation is unlikely as the fault current is only 3 times the CT current (1500).
Could the current in the CT be due to motor contribution?
How do we calculate motor contribution?
Thanks.
The CTs readings are
IA = 1710 deg 0
IB = 2180 deg 142
IC = 1642 deg 241
Ia = 4267 deg 89
Ib = 3915 deg 215
Ic = 3586 deg 329
The transformer vector is Dy1 and when measured in GE 745's convention, there's a 180deg phase difference. Thus, it seems like the phase shift during flashover is...
We have a transformer fault on a 33kV/6kV secondary linkbox of a 15MVA transformer.
The event recorder at the differential protection (using GE multilin 745) shows that the secondary CTs shows about 4000A (not the same value for all 3 pahses but about 4000A while the primary CTs shows about...
Dear Sir,
In IEC, there's a Ex 'n' and Ex 'e' construction. However, in NEMA, what's the equivalent?
If we need to use a motor in class 1 division 2 area with possibility of hydrogen (Group B). How can we specify for a NEMA frame-size motor?
Thanks.
Regards
etgbccc