I have been an Industrial Controls Technician since 1998. Jim you are an excellent instructor. Your approach to explaining RLL instructions and scan cycles for PLC's, is awesome.
Thanks for another great video. The graphs of current versus time are very helpful to remember exactly whats going on. Also very useful you gave example of resistor values used as i would have assumed they would have a much higher value. Thanks again
What is power rating of resistors? If there is 3A (total inrush 9A) inrush passing through each resistor (10 ohm), then using power equation P=I*I*R, power dissipated will be 90W. Can we use 90W resistors or we need to use "bigger" ones?
Customarily most electrical equipment includes a significant overrating factor to ensure longevity and safety. Example: a certain manufacturer may specify 1.25, 2X, or even 4X the calculated value
Jim, pls give us a real example. Lets say a 100 HP- 460V motor. If a wye-delta starter is used the initial voltage is 58%, what size resistor should be used to produce a similar effect in Primary resistors reduced voltage starters? 460 x 0.58 = 267 Volts, voltage drop is 460-267= 193. What size resistor will produce a 193 Voltage drop. Don't know how to apply ohms law!
Good question! Never thought about trying to make one type of reduced voltage starter "perform" like another one. I've got a bunch of 3 phase AC lectures I'll be publishing early this fall detailing 3 phase AC circuit analysis and power calculations, however, to calculate the resistance necessary to produce a desired voltage drop divide the desired voltage drop by the anticipated current.
Presuming you're referring to the resistors used on the rotor (ie: the secondary) of wound rotor induction motors for start up and primitive speed control? If so, yes, I'll be discussing wound rotor induction motors in the future. These rotor resistor configurations are slowly being replaced by motor drives, a slightly more sophisticated means of speed control. Until then check out the motor drives lectures at: ruclips.net/p/PLdnqjKaksr8qruLl85Uq3em62PjXlSNUF
I have been an Industrial Controls Technician since 1998. Jim you are an excellent instructor. Your approach to explaining RLL instructions and scan cycles for PLC's, is awesome.
Thanks for another great video. The graphs of current versus time are very helpful to remember exactly whats going on. Also very useful you gave example of resistor values used as i would have assumed they would have a much higher value. Thanks again
thanks Jim..you are incredible😍😍
What is power rating of resistors? If there is 3A (total inrush 9A) inrush passing through each resistor (10 ohm), then using power equation P=I*I*R, power dissipated will be 90W. Can we use 90W resistors or we need to use "bigger" ones?
Customarily most electrical equipment includes a significant overrating factor to ensure longevity and safety. Example: a certain manufacturer may specify 1.25, 2X, or even 4X the calculated value
Brilliant!
Could an on-delay timer be used instead of a speed switch?
Check it out: m.ruclips.net/video/aCDD_IHUnro/видео.html
where should i connect the 2 leads (X1 and X2) of the control circuit in the power circuit?
X1 and X2 are pilot level control voltage. Either 24vdc or 120vac. Check out the “basic ladder logic” lecture.
Thank you 🙏
Ohms law perhaps you've heard of it
Jim, pls give us a real example. Lets say a 100 HP- 460V motor. If a wye-delta starter is used the initial voltage is 58%, what size resistor should be used to produce a similar effect in Primary resistors reduced voltage starters? 460 x 0.58 = 267 Volts, voltage drop is 460-267= 193. What size resistor will produce a 193 Voltage drop. Don't know how to apply ohms law!
Good question! Never thought about trying to make one type of reduced voltage starter "perform" like another one. I've got a bunch of 3 phase AC lectures I'll be publishing early this fall detailing 3 phase AC circuit analysis and power calculations, however, to calculate the resistance necessary to produce a desired voltage drop divide the desired voltage drop by the anticipated current.
Can you do a video on secondary motor resistors, great work as always!
Presuming you're referring to the resistors used on the rotor (ie: the secondary) of wound rotor induction motors for start up and primitive speed control? If so, yes, I'll be discussing wound rotor induction motors in the future. These rotor resistor configurations are slowly being replaced by motor drives, a slightly more sophisticated means of speed control. Until then check out the motor drives lectures at: ruclips.net/p/PLdnqjKaksr8qruLl85Uq3em62PjXlSNUF
Jim Pytel yes and awesome,thanks.