3 Phase Delta-Wye DYn1 transformer has primary terminal H1 connected to cable A, H2 to cable B, and H3 to cable C. The secondary terminal X1 is connected to cable a, X2 to b, X3 to c and X0 to cable n. The phase rotation is ABC on secondary.
What external connection changes, on either...
We have 3 phase 26.4kV Delta - 490 volt Delta and 490 volt Wye, 3 winding transformer which feed 12 pulse rectifier on 490 volt side, generating about 3 MW for Traction service. This oil filled transformer has nameplate but no markings at 26.4kV bushings for H1, H2 and H3. Similarly on secondary...
Question : Rotation Direction of Harmonics. Why some CW and some CCW in 3 phase induction motor?
Assuming with A-B-C phasor sequence, a 3 phase induction motor field rotates clockwise. Assuming the motor has 4 poles, speed will be just under 1800 rpm clockwise for 60hz supply. If we decrease...
We are using Eaton's Microprocessor programmable feeder protection relay EDR-5000 as attached. The swgr factory had switched relay coil B connections as shown in the attached.
We are using the relay as simple phase and ground overcurrent relay. No voltage input and no directional settings.
The...
We have 13kV-480 volt, 3300kVA customer Transformer. I have a question regarding Magnetizing Inrush current of the transformer. I am confused with DC offset current during switch on.
1. Is DC offset a real DC current which is diminishing in magnitude immediately after switch on ? 2. What is the...
thread238-332968
1. I have received positive, negative and zero sequence impedance from the utility for 33 KV feeder, which will supply about 12 MVA to our substation. The measured ground grid resistance is 1 ohm. If I assume a ground fault where 40% of fault current returns thru ground and 60%...
