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  1. kashew

    Motor Flicker

    Hmmm ... you're right. I hadn't thought about it that way. But, why would the results be different using the two different methods? The voltage divider method gives a smaller flicker result.
  2. kashew

    Motor Flicker

    In three phase systems there are three mathematical vectors that are used to analyze the system. The 3 positive sequence vectors rotate as A-B-C 120 degrees apart, the 3 negative vectors rotate as A-C-B 120 degrees apart and the 3 zero sequence vectors are 0 degrees apart...kinda like have three...
  3. kashew

    Motor Flicker

    Yeah, I know what you mean. That was my first thought. I've been doing some more research and found an EBASCO manual that has a similar method. They include the motor impedance in the formula. The motor impedance is calculated with the following formula %Z= 10,000/KVAstart on a 100 KVA base...
  4. kashew

    Motor Flicker

    I've been calculating motor starting flicker using the basic formula: LRA x (R cos0 + X sin0) where cos0 = starting pf and R & X values are in ohms I've run across a different method of calculation that I'm not familiar with and was wondering if anyone could provide some insight. Is this...
  5. kashew

    Power Factors for Heat Pumps

    Where can I find a table with typical power factors for heat pumps and A/Cs?
  6. kashew

    Transformer specifications

    This is exactly what I have been searching. I was looking through the rest of the document and have a question. Table 17 lists cable resistance and reactance in magnetic and non-magnetic conduit. Are cable resistance and reactance for direct buried cable the same as the non-magnetic conduit...
  7. kashew

    Transformer specifications

    Can someone tell me if there is a reference that provides typical distribution transformer impedances? I'm looking for %Z and either X/R ratios or %X and %R values. The X/R table in IEEE red book is not adequate.
  8. kashew

    Transformer Impedances

    Can someone tell me if there is a reference that provides typical distribution transformer impedances? I'm looking for %Z and either X/R ratios or %X and %R values. The X/R table in IEEE Red Book is not adequate.
  9. kashew

    Parallel cable impedance

    In the IEEE Buff Book (ANSI/IEEE std 242-1986) more specifically page 94, figure 21 shows the basic formula for calculating parallel impedance. Z= (R1+jX1)*(R2+jX2)/(R1+jX1)+(R2+jX2) If you substitute some simple whole numbers for the values such as R=2 and X=2 (for ease of calculation) the...
  10. kashew

    Parallel Conductor Impedances

    In the IEEE Buff Book (ANSI/IEEE std 242-1986) more specifically page 94, figure 21 shows the basic formula for calculating parallel impedance. Z= (R1+jX1)*(R2+jX2)/(R1+jX1)+(R2+jX2) If you substitute some simple whole numbers for the values such as r=2 and x=2 (for ease of calculation) the...

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