Hi everyone,

I am new member here. I am also a new engineer, fresh out of college, tasked to do arc flash studies for a hydro-plant. I have the all the information I require but I need some help in modeling my system. I am unsure what to model and what to ignore using PTW 6.5 to do my short circuit study and arc flash analysis. Hopefully some one here have can help me out and give me some tips and advice to guide me along. Here are some of my questions:

1. Do I model surge arrestors/capacitors in my model?
2. In the one-line I see "slug transformer fuse," do I just model those the same way I model fuses?
3. In modeling a generator, where do I account for Xd"?
4. I have a three-way transfer switch, with one position being the emergency generator for the system, how do I model this in PTW?
5. I have the tutorial for PTW but was wondering if they have an in-depth user manual?


Those are my questions. Thank you for your help.

Vong

PTW Training

1. Do I model surge arrestors/capacitors in my model?
No. Not important for arc flash analysis.

2. In the one-line I see "slug transformer fuse," do I just model those the same way I model fuses?
"Slug transformer fuse" must be a local jargon. The word "slug" doesn't appear in the PTW Help file. A Google search only showed your entry on this website.

3. In modeling a generator, where do I account for Xd"?
Under Synchronous Generator, Component Editor, ANSI Contribution subview, X" per unit values for Pos, Neg and Zero sequences can be entered.

4. I have a three-way transfer switch, with one position being the emergency generator for the system, how do I model this in PTW?
Each position of the transfer switch should be modeled as a separate Scenario.

5. I have the tutorial for PTW but was wondering if they have an in-depth user manual?
I have not seen a manual. But the training manual from SKM is valuable, so is their built-in help file. For any window select F1 to get Help. If your software is properly licensed you can also get factory help. The "Help" menu has their phone number and your serial number that you'll need for assistance.

You should attend a PTW training class. Otherwise you will spend a lot of time asking novice questions. College is over. Now the real learning begins.

Thank you for your reply. It was helpful. I am currently trying out the software with their trial version and so their is no "F1" help menu and not sure about the phone support. My company is still deciding to on whether to purchase it or not.

A "slug" sometimes refers to the use of a solid conductor or an oversized fuse in a fuse block instead of a properly sized fuse. Is other protection provided for the transformer.[url="http://www.electriciansupplies.com/index.cfm/S/235/CLID/1750/Dummy_Fuses.htm"]http://www.electriciansupplies.com/index.cfm/S/235/CLID/1750/Dummy_Fuses.htm[/url]

Thanks stevenal. Yes, there are fuses upstream to protect the transformer.

SKM training

I attended the SKM 1 week training class in October 2010 at Torrance CA. It was a very solid week of training. Since then I have used the SKM product weekly, sometimes daily.

After several months I do not feel expert, just marginally competent. SKM has a lot to learn and has a lot of capabilities and several quirks. Summary, training highly recommended.

About me, I am an EE, power systems are a newer area for me, more of a controls background. And yes I am a P.E., I passed the exam first attempt years ago. Not sure I could repeat that accomplishment today.