Procedure for selection of resistors, Rf1 & rf2 resistor, Rf” resistor tap settings – Rockwell Automation 1902 Syncpro II User Manual
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Rockwell Automation Publication 1902-IN001B-EN-E - April 2013
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Setup and Commissioning
Chapter 4
Procedure for Selection of
Resistors
RF1 & RF2 Resistor
“RF” Resistor tap settings
Figure 11 - Discharge Resistor Setup
RD = Discharge resistance
__________
Ω
RSD = Sample resistance
__________
Ω
Vpp0 = 0% speed peak to peak voltage
__________ V (Vpeak@0)
Vpp95 = 95% speed peak to peak voltage
__________ V (Vpeak@95)
Vrms 0 = Induced voltage (0% speed)
__________ V (Vrms@0) Vp0/2.828
Vrms 95 = Induced voltage (95% speed)
__________ V (Vrms@95) Vp95/2.828
Io = Induced current (0% speed)
__________ A (Arms@0)Vrms0/Rs
I95 = Induced current (95% speed)
__________ A (Arms@95)Vrms95/Rs
V0 = Induced voltage (0% speed)
__________ V I0 x Rd
V95 = Induced voltage (95% speed)
__________ V I95 x Rd
0 speed induced voltage across the entire discharge resistor
50
Ω * 20 A= 1000V
95% speed induced voltage across the entire discharge resistor
50
Ω * 12 A = 600V
R
F
1/R
F
2 Resistance Required
__________
Ω