Hi ,
I am sure some of you gurus work in utilities at a managerial or supervisor level. I will be interviewed for an Engineering Specialist position for a local distribution company. I come from a consulting engineering background.
I was wondering, if you guys could explain me this role in a...
Hi My thread consists of two questions:
Q#1 : What value of fault current is considered for CT saturation calculations: IEEE std is not very clear on this.
A) ASymmetrical RMS 3 Phase fault Current(RMS)- 1/2 Cycle
B) Symmetrical RMS 3 Phase fault Current(RMS)- 5 Cycle
Q#2 In the past, I...
Hi,
IEEE C62.92.2 part 2 for neutral grounding talks about using a disttribution transformer in the neutral for high resistance grounding of generator.
Recently, I saw an application of a 3 MVA 4.16 kV Generator where there was a NGR directly connected to the generator neutral rated at 15 A...
Hi...
You have been all of great help me in the past while answering my questions.
I am working on a grounding grid study and some how I found this document that talks about client requirements. I am just having a hard time understanding this. I would appreciate, if you could elaborate...
Hi,
I was wondering, if during a ground fault on the primary of a 44 kV transformer in a substation, if the system feeding the fault is a 3 Ph 4 wire system and the fourth wire could be either Neutral or ground and this wire is connected to the grounding grid being designed.
Major part of the...
Hi,
I am trying to create a flyer or a pamplet to market my company's arc flash study expertise in US and Canada. I am originally from Canada but not familiar with US requirements. I am sure they are quite the same but would certainly would be interested in knowing NEC termnilogy.
Could you...
Hi All,
I am seeking a logical explanation for a new transformer grounding. It is Pig/Hog processing facility and the owner is planning an expansion. I am new to this world of industrial installations and I am sure you guys have seen and done it all.
They plan to install one big 66 kV/13.8kV...
Hi,
I am an industrial consulting engineer and don't work in a utility but we have a client who has a substation at 69 kV that needs some buried cable work at 69 kV. It is in Alberta and client does not this cable to be armoured.
Is it possible to be a unarmoured cable to be direct buried. I...
Hi,
A client intends to use an existing 350 HP VFD for a new 200 HP fan Load on 600 V. These are for variable torque loads(vent fan application).
I was wondering, if I should be concerned about any issues while using a higher size VFD for a smaller load.
Q#2, What is the criteria for sizing...
I am working on a oil & gas project in west coast of Canada. It is a 69 kV cable being fed from a GIS substation and powering a 12 MVA transformer with bushings at the bottom in a cable box. So no exposed bushings and no lihgtning arresters.
Due to Client request, my back is against the wall...
Hi,
I am going through an arc flash remediation issue. The primary of the transformer is fed from a non fusible disconnect switch.
It is a 600 V primary system for a 225 kVA transformer.
They want to make sure that during secondary breaker operation on 208 V, arc flash hazard is limited...
Hi..
I am trying to study transformer differential protection and I guess I have gone through IEEE std and some noted book but I did not get a single document that could give me an example of a traditional approach. Everywhere it is more conceptual.
Could you advise me a book or an IEEE...
Hi All,
I read quite a bit of posts on this topic but would apprecaite, if you could advise if I got it right.
Please advise, if I am missing any thing here.
1. HV/MV Breaker: Modern microprocessor relays only measure symmetrical rms value of current becasue they filter out the DC Component...
Hi All,
I am sure there are people on the forum working in utilities. I was wondering, if any one of you could kindly put a word for the job responsibilities for a planning engineer.
I am trying to find out if I am a fit for this kind of position.
Thanks
Hi All,
I have read this at many places that T/F has max efficiency if operated near the saturation curve but I could not find a decent explanation.
Q#1 How this improves efficiency
Q#2 How we can make a transformer operate near saturation.
I would appreciate a word.
Thanks
Hi,
I would appreciate some insight in to some conceptual issue in regards to an equivalent circuit of Current transformer and Voltage tansformer and a regular tranformer. I am not sure, why I ended up having this confusion but after searching books like Blackburn on issue of CT/PT, I could...
Hi All,
I am sure that there might have been discussions about inrush current but I did not find any information relevant to my question.
I am trying to justify an information received from a manufacturer about inrush current calculation on a 1 MVA 13.8 kv transformer Dry type transformer. It...
Hi All,
This is my first post on Motor section and I have already browsed earlier posts to find out if there is an answer available.
I have to protect a 400 HP motor at 600 V with a VFD. The motor has an RTD and Bentley nevada vibration monitor.
This is what i intend to do and seeking an...
Hi,
Before I joined consulting engineering, I had no clue that I might have to excel in to MS office packages and SQL stuff. My company does a lot of feasibility studies with basic fees up to millions of dollars. I am at a Jr position and the besign design starts from my threshold.
I was...
Hi All,
I was simulating a network on ETAP and
Just out of curosity, analyzed results in seq. components form.
When representing a network in to Positive, -Ve and Zero seq. network, Postive seq. network has a voltage source in sries with it on the other hand a -ve seq. network has just the...
