Yaskawa YASNAC PC NC Connecting Manual - Manual (Page 73)

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YASNAC PCNC Connecting Manual Chapter 6: Connection with the Servopack
6.2.4 Selection of the Converter
It is necessary to select the converter based on satisfying the following three conditions:
CONDITION 1:
•
The rated output of the selected converter must be larger than the following value:
(Rated spindle output x 1.1) + (Total rated servomotor’s outputs x 0.6)
CONDITION 2:
• The one second rating of the selected converter (2 times the continuous rating) must be greater
than the value shown below.
CONDITION 3:
• The one minute rating of the selected converter (1.2 times the continuous rating) must be
larger than the momentary max. output value of spindle motor.
An example of converter selection procedure is show below:
Motors used: X-axis: SGMG-20 (Max. 2000 r/min)
Y-axis: SGMG-20 (Max. 2000 r/min)
Z-axis: SGMG-30 (Max. 1500 r/min)
Spindle: UAASWD-22CX1:
7.5kW (10HP)(cont. rating)
11 kW (15HP)(30 min. rating)
26 kW (34.8HP)(1 min. rating)
• Continuous rating:
7.5kW x 1.1 + (1.08kW x 2 + 1.74kW) = 12.12kW( Selected 15 kw Converter)
• Maximum momentary servo output:
5.99kW x 2 + 7.12 kW = 19.1kW ( Selected 11 kW converter )
• Spindle acceleration/deceleration
Momentary max. output value of spindle motor: 26kW : ( 22 kW * 1.2 )
(converter with 22kW ratings)
From the calculation indicated above, the converter with 22kW rating that satisfies all
conditions that should be selected.