Search:

Type: Posts; User: dickricker

Search: Search took 0.22 seconds.

  1. Replies
    12$$
    Views
    1,383

    I understand the 30 Amp breaker (MOC); but please...

    I understand the 30 Amp breaker (MOC); but please explain 19.7 Amps through 14 AWG wire. Thank You!
  2. Replies
    18$$
    Views
    4,266

    Good Point! Thank You!

    Good Point! Thank You!
  3. Replies
    18$$
    Views
    4,266

    Thank You, Augie47! Just to be 100% clear: ...

    Thank You, Augie47!

    Just to be 100% clear:

    Do you mean that I could use a 1200 Amp branch and a 1600 Amp feeder OCP device with feeder conductor ampacity following 430.24?

    Do you interpret...
  4. Replies
    18$$
    Views
    4,266

    Yes. Thank You. The 430.24 rule can be quite a...

    Yes. Thank You. The 430.24 rule can be quite a money and work saver.
  5. Replies
    18$$
    Views
    4,266

    Yes. Yes. I agree 100% However, the 430.62...

    Yes. Yes. I agree 100%

    However, the 430.62 question remains. Using 430.24 feeder conductor ampacity, following 430.62, using a 1600 Amp (or 1200 Amp) motor branch circuit breaker to calculate...
  6. Replies
    18$$
    Views
    4,266

    Good Point. Thank You! However, we do want to...

    Good Point. Thank You!

    However, we do want to base our feeder conductor ampacity on 430.24 --- that would be 862 Amps. Feeder conductor size to match the feeder breaker would require 1600 Amp...
  7. Replies
    18$$
    Views
    4,266

    NEC 2011 430.62 (A) says: Specific Load. A...

    NEC 2011 430.62 (A) says:
    Specific Load. A feeder supplying a specific fixed motor load(s) and consisting of conductor sizes based on 430.24 shall be provided with a protective device having a...
  8. Replies
    18$$
    Views
    4,266

    Thank you all for your input. In answer: ...

    Thank you all for your input.

    In answer:

    Why 2 sets of breakers on a single circuit?

    We have a feeder running out to the panel which contains the motor branch circuit breakers near...
  9. Replies
    18$$
    Views
    4,266

    Motor Feeder Breaker Size

    Hi,

    Following NEC 2011, I have a question concerning motor feeder circuit breaker size.

    Motor 1: 100 HP, 460 VAC, soft-starter controlled, NEC FLC = 124 A (Table 430.250)
    Motor 2: 500 HP, 460...
  10. Replies
    2$$
    Views
    494

    Page 33 lists the nameplate FLA of large 460 VAC...

    Page 33 lists the nameplate FLA of large 460 VAC motors --- Thank You!

    However, NEC Article 430.6 says that Tables 430.247 - 430.250 must be used to determine the ampacity of the motor conductors,...
  11. Replies
    2$$
    Views
    494

    Large Motor FLC

    NEC 2011, Table 430.250 only goes to 500 HP.
    I have heard that for larger 460 VAC motors, use 1.2 FLC per HP, or exterpolate. But I cannot find a reference.
    Please, what is the official NEC rule...
  12. Good Question. My understanding is that...

    Good Question.



    My understanding is that with a VFD, we use VFD nameplate current; but with a soft starter, since it connects across-the-line after starting, we use the motor HP and associated...
  13. Thank You, iceworm! What I mean is a...

    Thank You, iceworm!



    What I mean is a breaker which is designed for motor service and has adjustable instantaneous trip which also adjusts the trip curve (like the Siemens ND63B12). We know...
  14. Large Transformer Secondary Breaker NEC Requirement

    Hello,
    New to this forum. New to specifying large transformers.

    Starting with the load and working backwards.

    Two 600 HP, 480 VAC, 60 Hz, three phase motors. NEC FLC = 720 A. Nameplate FLA...
Results 1 to 14 of 14