Rockwell Automation 1902 Syncpro II - Manual (Page 33)

Rockwell Automation Publication 1902-IN001B-EN-E - April 2013 35
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