1. Create Your User Profile and Status Updates

    Arc Flash Forum members are invited to create a user profile. Let others know who you are, what you do and even add a picture or avatar of yourself. What are you up to? Let people in the arc flash and electrical safety community know with "status updates"!
  2. Welcome to the All New Arc Flash Forum

    Arc Flash Forum is a community where we help each other learn about arc flash and electrical safety. There is still much to be learned about arc flash, standards, PPE, studies and more and We need your HELP!

    If you have good information about Arc Flash - Post It! If you have a question about Arc Flash - Post It! If you can provide answers to Arc Flash questions - Post it!

    Sign up as a today member! Feel free to link to this site www.arcflashforum.com. Tell your friends. We want to help everyone be safe in the workplace!
  3. Bigger and Better!

    As you have no doubt noticed, the forum has been through quite an upgraded and looks and feels very nice! There are loads of new features and ways in which this site can now be even more useful to the community in learning about Arc Flash and Electrical Safety.

    Create your detailed user profile
    Add a profile photo of yourself
    Like the forum on Facebook
    "Like" users' posts
    Publish your articles in the library
    ...and much, much more!

    Learn More About the New Features Here
Create Your User Profile and Status Updates Welcome Message Arc Flash Forum has been Upgraded!

PTW32 Single Phase Equipment

Discussion in 'Software for Arc Flash Studies' started by zrjohnso, Jul 16, 2008.

  1. zrjohnso New Member

    PTW32 isn't allowing me to calculate arc flash for single phase equipment. I noticed that the calculations assume a three phase fault, but I figure that I should worry about single phase transformers too, right? Or am I just doing something wrong? Sorry if this is a dumb question.
    zrjohnso, Jul 16, 2008
    #1

  2. Zog Well-Known Member

    You need to purchase the single phase module from SKM.
    Zog, Jul 16, 2008
    #2

  3. Noah Member

    I am using PTW32 too, can anyone explain why I have to use comprehensive SC for Arc fault calculation? What's the big difference if I want to use A_Fault? Thanks!
    Noah, Jul 17, 2008
    #3

  4. zrjohnso New Member

    I just emailed SKM support and they said that the existing standards don't address single phase systems. I haven't read that anywhere, but is this correct?
    zrjohnso, Jul 18, 2008
    #4

  5. zrjohnso New Member

    Noah,

    If you haven't already, I would suggest emailing support@skm.com. I don't know enough about SKM yet to be helpful.
    zrjohnso, Jul 18, 2008
    #5

  6. brainfiller Administrator

    Right now the IEEE 1584 models are all three phase. The 1584 standard lists this in Section 5.1 but it is not obvious unless you go looking for it. The reasoning for the three phase model is that although the majority of short circuits (bolted and arcing) on grounded systems might originate as a line-ground event, a line-ground arc flash can quickly escalate into a three phase event almost instantaneously due to the conducting nature of the plasma (a.k.a. fire ball).

    For now, three phase models are all that exist within 1584.

    A few companies like Kinectrics (Ontario-Hydro) have developed their own single phase models for overhead transmission and distribution lines but for equipment at lower voltages we only have three phase models.
    brainfiller, Jul 18, 2008
    #6

  7. amohammed New Member

    Noah,

    I do not know if someone has answered your question or not but I believe the difference is in the fault current magnitude. The fault current magnitude obtained using comprehensive method (which is strictly theoretical) is the same as the ANSI fault during the first half of cycle with small variation in X/R ratio. After that the ANSI multipliers for sources and motor contributions kick in...which eventually reduces the magnitude.

    The arc-flash result should remain the same since PTW uses initial symmetrical RMS current (at 1/2 cycle) for its calculations.

    Aleen
    Burns & McDonnell
    amohammed, Jun 14, 2009
    #7

Share This Page