
7.DETERMINING THE ALLOWABLE DUTY CYCLE SPECIFICATIONS FOR THE αi SERIES B-65272EN/04
- 40 -
NOTE
1 Cutting output P
3
at motor speed N which is lower
than base speed Nb shall be calculated by the
following equation.
P
3
=P
C
× Nb/N [kW] (P
C
: Actual cutting output)
2 In case that P
3
is calculated by the load indicator
voltage, use the following equation.
P
3
=P
1
× L
3
/10 [kW]
(L
3
: Load indicator voltage in cutting [V])
Allowable duty cycle time Dt
From the equation for getting the value of Pav[kW].
1
Dt= × (P
1
2
t1+P
2
2
t2+P
3
2
t3+P
4
2
t4)
Pav
2
Substitute the continuous rated output of the used AC spindle motor
for Pav [kW] in the equation above.
Example)
To obtain the allowable duty cycle when model α3i accelerates
and decelerates repeatedly without load (P
2
=P
3
=0).
- Continuous rated output Pav=Pcont=3.7kW
- Acceleration/deceleration output P
1
=P
4
=5.5kW×1.2=6.6kW
- Acceleration time t1=3s, deceleration time t4=3s
1
Dt=
×(6.6
2
×3+6.6
2
×3)=19.1 seconds
3.7
2
As shown above, when model α3i accelerates and decelerates
repeatedly, the allowable duty cycle time is 19 seconds.