Hello. I wonder if single phase and three phase valve actuators have any advantages relative to each other? I guess three phase motors are the preferred type so I just wonder if the two types are interchangeable in a project.
Thank you in advance
According to “precisioin digital”, the term 'loop-powered' is synonymous with the term '2-wire' (meaning that only 2 connections/wires are involved in any of the connections between the transmitter, the power source and the output device).
However, PRtrans and M-System (attached file)...
In searching for conversion of 4-20mA to millivolt signal, I encountered a statement in an Emerson document as attached. It says "Conversion of a 4-20 mA source to a measurable millivolt signal constitutes a second power source in the terminal block of the Rosemount 644". I wonder why this is...
Most of the Standards like IEEE 535 and IEEE 666 talk about Lead-Acid batteries for nuclear power plants. Also, as far as I know, several modern nuclear power plants currently under construction also plan to use Lead-acid batteries. However, as we all know, recently Ni-Cd batteries have gained...
We have a thermal power plant with a multi-megawatt generator of 15 kV voltage. It is connected to the grid through a 15/400 kV transformer. Definitely, the generator has its own AVR system. But I wonder if it is also necessary to have an AVR panel for the 15/400 kV transformer?
In...
When we perform a DC power flow, all bus angles are obtained. Then we can calculate line power flows. Then I would also like to calculate the real power injected by the reference (Slack) bus to the grid since we have not specified any power to this bus to begin with.
However, the power obtained...
I wonder if we can generally say that a T3B motor is better than T2B because of higher surface temperature?
or in the contrary, can a higher surface temperature (like T3B) for a motor possibly have higher risk of causing explosion in the area than a lower surface temp. motor (T2B)? Please let...
I heard from a friend of mine that DC breakers have higher current interruption capability than AC ones. I wonder if we can use AC breakers, maybe with some derating, for DC application? or vice versa? I have seen many MCBs and MCCBs that are used for both DC and AC application. Even their...
I wonder if MV CBs have, just like LV CBs, current limiting capability? The current limiting capability makes us able to lower the size of downstream breakers, cables and other equipment.
Thanks in advance
Suppose we are going to design a plant power distribution network with some MV and LV loads and buses. If we design our LV network as TNC-S, where is the best point in our LV network to separate neutral conductor from PE conductor? Is it in the main LV switchgear or in the downstream MCCs or...
Suppose we have to supply power from an LV switchgear to a large MCC with a rating of 2500A. We will be forced to use multiple runs of cable for each phase.
I wonder if the number of neutral and PE conductors shall also be the same as the phase runs?
Thanks in advance
3ph motors usually have their metallic body grounded either to the PE conductor of their power supply or to the earthing system terminal locally established in the building.
I wonder which of the above two methods is the most appropriate?
Thanks in advance
