IAI MCON-C, Instruction Manual

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1.3 Calculation for Power Capacity
For the calculation of 24V DC power capacity, figure out the numbers for (1) to (6) below, and then
follow Step (7).
(1) Control Power Current Consumption : 1.0A·································································1)
(2) Motor Power Current Consumption :
Add the total motor current consumption of all connected actuators.·································2)
(3) Current Consumption at Excitation Phase Detection :
Add the inrush current for all connected axes. ·····························································3)
(4) Add the Control Power Inrush Current : 5A ·································································4)
(5) Add the Motor Power Inrush Current : Number of slots × 10A each. ·································5)
(6) Current Consumption of Brake Release Power: Number of actuators with brake × 0.15A······6)
(7) Selection of Power Supply :
Usually, the rated current is to be approximately 1.3 times higher than the total of Control Power 1) + 2)
+ 6) above considering approximately 30% of margin to the load current. However, considering the
inrush currents [excitation 3), control 4) and motor power 5)], even though it is a short time, select a
power supply with “sufficient peak load capacity. Avoid current of 3) to 5) from occurring at the same
time by having the timing of emergency stop release (turning the motor power on) and timing to
turn the servo on shifted
(Note 1)
from each other and so on. Huge current flow of the same time
may cause a transient voltage drop. Be careful especially when selecting a power source
equipped with remote sensing.
Note1 The timing to turn the servo on can be shifted in Driver Shutdown Release Delay Time
[refer to 3.9.9 3) GW Parameter 3] in the gateway parameter setting tool.
(Note) Ensure motor and control power supplies reference the same potential when using
multiple power supplies.
(Reference) Selection of Power Supply Protection Circuit Breaker
It is recommended that the power supply protection is conducted on the primary
side (AC power side) of the 24V DC power supply unit.
When selecting the protection breaker, consider the rated cutoff current of the
circuit breaker so a cutoff is surely performed even in the case of inrush current of
24V DC power supply unit or a short-circuit of the power supply.
• Rated Breaking Current > Short-circuit Current = Primary Power Supply Capacity /
Power Voltage
• (Reference) In-rush Current of IAI Power Supply Unit PS241 = 50 to 60A, 3msec
Chapter 1 Specifications Check