Fagor DCM21 System Manual page 20

Adjustment of IM components for governing Non-Fagor motors
RTV1 calculation:
Vmaxtac = Nmax · 1.3 · Ktac
RTV1 = Vmaxtac - 22 (KΩ)
This RTV1 must be of 1/4 Watts
This calculation is independent of whether the maximum speed is later limited with Max.Speed
or not.
This calculation is OK for velocity commands of ±10V.
If, for example, the command is ±8V for a maximum speed of ±1200 rpm, the previous
calculation will result in 1200·10/8 = 1500 rpm.
Graph for calculating the RTV1 resistor when
using a 20 V/Krpm tacho.
(the one carried by the Fagor motors mentioned
in this manual)
RAJFV calculation:
RAJFV (KΩ) =
This RAJFV must be of 1/4 Watt
This calculation is independent of whether the maximum speed is later limited with Max.Speed
or not.
This calculation is OK for velocity commands of ±10V.
If for example, the command is ±8V for a maximum speed of ±1200 rpm, the previous
calculation will result in a maximum speed of 1200·10/8 = 1500 rpm.
RIT calculation:
RIT (KΩ) =
In · K
This RIT must be of 1/4 Watt
"In" is the rated current of the motor according to the characteristics table or the current used in
a duty cycle considered nominal.
Codes of the sales reference for the identity cards:
DC - 20/32
68,4 · 10 6
(Pulses/turn) · Nmax · 1.15
where:
150
K = 0.39 (DCS-8)
- 10
K = 0.22 (DCS-14)
IDENTITY MODULE
IDENTITY MODULE
MOTOR TYPE
DRIVE TYPE
Example of calculation:
Maximum Speed: 1200 rpm
Tacho Constant: 20 V/Krpm
1200 · 1.3 · 0.02 = 31.2
RTV1 = 31.2 - 22 = 9.2 KΩ / 0.25 W
Nmax (rpm)
RTV1
(for Ktac = 20 V/Krpm)
4000
3000
2000
1000
10 20 30 40 50 60 70
Example of calculation:
Maximum Speed: 1200 rpm
Encoder pulses per turn: 2500
68,4 · 10
RAJFV (KΩ) =
2500 · 1200 · 1.15
Example of calculation:
DCS-08 drive
DCM41.20 motor : In = 4.72 Amp
150
RIT (KΩ) =
4.72 · 0.39
Example: IM - 4120A - 14
DC Servo Drive System Manual Ver: 0009
RTV1
(k Ω )
80
6
= 19.8 KΩ
- 10 = 71.5 KΩ