It has been a very long time since I graduated and now work in a component dedication lab where I have been asked to verify the characteristics of an op amp. Most of this I can do without too much stress, but I have been unable to find a solution that makes sense to me for measuring open-loop...
Ok. First, I am new to the field of electromagnetic compatibility. I am an EE who was voluntold to take over the EMI/RFI lab where I work. No experience.
I have the basic knowledge after reading a lot of the IEC and MIL-STD documents on EMC, but I am at a loss on some of this and I need some...
I am doing conductor voltage drop calculations for a new subdivision. The secondary from my pad mount transformer is -probably- going to wind up at 350kcmil, but I need justification. I have 2 pedestals downstream from my xfmr. Each is feeding 2 single family dwellings with an estimated 10kW...
I am looking for service entrance clearance requirements.
I have found the minimum vertical requirements above grade, stuctures etc. for the service conductors. (225.18, 225.19, 230.24 & 230.26)
I have also located MOST of the working space requirements for the meter socket (110.26)
What I...
Ok, no dramatic way to ask, so I'll just jump right in.
I have in front of me as I write copies of IEEE C37.20.3 and C37.20.2
Outside of some minor differences in ratings and the rather lengthy definition atributed to MC gear, I can not find a significant difference between the 2. So, is there...
I don't understand the differences between types of transformers. Specifically, what are the differences between isolation transformers, regulating transformers, and power transformers.
I was under the impression that ANY transformer, with the exception of autotransformers, were isolating and...
I have no idea what this is and I was hoping one of you folks could explain what pulverizer fogging is with respect to a coal fired power plant. Can anyone give me an idea of what this is exactly?
I would ask around my office, but frankly I would rather appear ignorant in front of people I...
I have been reviewing a bunch of specifications for a power plant that my company is helping to engineer and I am getting confused reviewing the one on medium voltage cables.
I have 2 separate specifications (I am functioning as owner's engineer here). I have a spec from the actual engineering...
I am a relatively recent grad and am still trying to learn what I assume are basics of the power protection systems in fossil power plants.
I am working to gain an understanding of the operation of LV and MV switchgear/breakers etc. I have manual from Schneider that I downloaded from their web...
Ok, here is another newbie question.
I understand the physics behind the induction motor and the electromechanics, but what I don't get is the slip.
I know the math behind it, but I don't understand how it the rotor can be running slower than the rotating field.
Here's what I mean: I have a...
OK. This question will probably show just how unprepared I am to do my job, but I'm still going to ask.
I am a recent grad with my BSEE, I won't say from where to protect the name of the institution.
I am working as a consultant for the time being.
I want to know more about MV switchgear. In...
It has been a really long time since I took chemistry. I was asked to review some documents for a project I am wokring on. Some of the docs apply to the UPS and battery systems.
Can someone post or point me to the chemical reactions that are taking place and why this happens?
I have beat this horse before, but this time it comes from a different source. I hav attached a page from a manual produced by the Army Corp of Engineers for their training. I have a real problem understanding where they are getting the 18.271A for the fault at LC BUS. Nothing I do gets that...
I am in the process of updating/replacing some relays for a hydro plant and am running into problems using ETAP. I have looked in the no-help files and found nothing. There is no one in the office here that understands ETAP even as well as I do (sadly). Here is a brief overview of the problem I...
I am programming a microcontroller to function as my PID control for a DC motor. The current is delivered via jfet stimulated by the microcontroller using PWM. I understand enough about PWM and dc motor control to make me a little dangerous. I know I need to set the period and duty cycle, but...
I am currently working on a calculation of short-circuit current forces for a 3-phase horizontal bus system.
I have exhausted my didactic sources and a few online sources looking for the method used to calculate these forces. Is there anyone who can deliver a formula or 2 to help me out?
I...
I understand from IEEE that the high side of a 3p transformer whether delta or wye always leads the low side by 30 electrical deg. (IEEE standard apparently)
I have been told that it is possible to achieve a different angle from a transformer.
I assume this is done by hooking up the phases in...
Ok. New grad here working in power generation industry.
I have been given the task of calculating the short circuit fault current in a bus system given the following information:
4-Hydro generators rated at 38.5MVA, 13.8kV : grounded wye conneced (I am given no further info about the...
