IAI MSCON, Instruction Manual

Page: 35 / 360

Chapter 1 Specifications Check
27
1.3.3 Selection of Leak Current Breaker
• It may be mandatory by law to install a leakage breaker.
• A ground fault circuit interrupter needs to be selected carefully considering the purposes of
prevention of fire and protection of human (Determined by law).
• Leak current varies depending on the capacity of connected motor, cable length and the
surrounding environment. Measure the leak current at the point where a ground fault circuit
interrupter is to be installed when leakage protection is conducted.
• Use the harmonic type (for inverter) for the ground fault circuit interrupter.
1.3.4 Control Power (24V DC) Capacity
Follow the description below for the calculation of 24V DC power capacity.
(1) Control Power Current Consumption :
Select from control power supply current in the table below ········································· 1)
Number of Controlled
Axes
(Note1)
1 axis 2 axis 3 axis 4 axis 5 axis 6 axis
Control Power Unit
Heating Value [W]
25.5 31.5 38.2 44.2 50.9 56.9
Control Power
Capacity [A]
1.1 1.3 1.6 1.8 2.1 2.4
Note 1: See the line of max. number of controlled axes connectable to corresponding
MSCON.
It can be defined on the manufacturing name plate.
MSCON-C-*-• • • •: “*” is the maximum number of connectable axes.
(2) Current Consumption of Brake Power Supply:
1A or 0.5A
(Note 2)
×
number of brake-equipped actuators ·············································· 2)
Note 2: The maximum current of 1A per actuator runs for approximately 100ms when a brake
is released. The current consumption after the release is 0.5A per unit.
Calculate the capacity with 0.5A per unit when a 24V DC power supply corresponding
to transient load change such as peak load appliance is used and capable for the
maximum current described above. For other cases, calculate with 1A per unit.
(3) Add the Control Power In Rush Current: 7A ····························································· 3)
[Selection of Power Supply]
Usually, the rated current is to be approximately 1.3 times higher than the total of Control
Power 1) and Motor Power 2) above considering approximately 30% of margin to the load
current. However, considering the inrush currents [excitation (3)], even though it is a short
time, select a power supply with sufficient “peak load capacity”. If a power supply with
insufficient peak capacity is utilized, a transient voltage drop or cutoff may occur. This may
present issues with power supplies providing remote sensing functionality.
(Remark) 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.
If having 24V DC turned ON/OFF, keep the 0V connected and have the +24V ON/OFF
(cut one side only).
Be careful to the in-rush current of the 24V DC power supply unit when making a
selection. (Check it in the operation characteristics curve graph in a catalog provided by
the supplier.)
Consider the current that enables to cutoff the current even when a short circuit current is
flown for the rated cutoff current.
y
Rated Interrupting Current > Short Circuit Current = Circuit Breaker Primary Power
Capacity / Power Voltage
y
(Remark) In-rush Current of IAI Power Supply Unit PS241 = 50 to 60A, 3msec
ME0306-2A