Omron NJ501-4500 Manual page 22

Precautions for Safe Use
Power Supply Design
• Do not exceed the rated supply capacity of the Power Supply Units used in the Controller system.
The rated supply capacities are given in the NJ-series CPU Unit Hardware User's Manual (Cat. No.
W500).
If the capacity is exceeded, operation may stop, malfunctions may occur, or data may not be backed
up normally for power interruptions.
Use only NJ-series Power Supply Units on NJ-series CPU Racks and Expansion Racks.
Operation is not possible if a CJ-series Power Supply Unit is used with an NJ-series CPU Unit or an
NJ-series Power Supply Unit is used with a CJ-series Units.
• Do not apply voltages or connect loads to the Output Units or slaves in excess of the maximum rat-
ings.
• Surge current occurs when the power supply is turned ON. When selecting fuses or breakers for
external circuits, consider the above precaution and allow sufficient margin in shut-off performance.
Refer to the NJ-series CPU Unit Hardware User's Manual (Cat. No. W500) for surge current specifi-
cations.
• If the full dielectric strength voltage is applied or turned OFF using the switch on the tester, the gener-
ated impulse voltage may damage the Power Supply Unit. Use the adjustment on the tester to grad-
ually increase and decrease the voltage.
• Apply the voltage between the Power Supply Unit's L1 or L2 terminal and the GR terminal when test-
ing insulation and dielectric strength.
• Do not supply AC power from an inverter or other device with a square-wave output. Internal tem-
perature rise may result in smoking or burning. Always input a sinusoidal wave with the frequency
that is given in the NJ-series CPU Unit Hardware User's Manual (Cat. No. W500).
• Install external breakers and take other safety measures against short-circuiting in external wiring.
When Power Is Turned ON
• It takes up to approximately 10 to 20 seconds to enter RUN mode after the power is turned ON.
During that time, outputs will be OFF or will be the values specified in the Unit or slave settings, and
external communications cannot be performed. Use the RUN output on the Power Supply Unit, for
example, to implement fail-safe circuits so that external devices do not operate incorrectly.
• Configure the external circuits so that the power supply to the control system turns ON only after the
power supply to the Controller has turned ON. If the power supply to the Controller is turned ON after
the control power supply, temporary errors may result in incorrect control system signals because the
output terminals on Output Units may momentarily turn ON when power supply is turned ON to the
Controller.
Actual Operation
Check the user program, data, and parameter settings for proper execution before you use them for
actual operation.
Turning OFF the Power Supply
• Do not turn OFF the power supply to the Controller while the BUSY indicator flashes. While the
BUSY indicator is flashing, the user program and settings in the CPU Unit are being backed up in the
built-in non-volatile memory. This data will not be backed up correctly if the power supply is turned
OFF. The next time that the Controller is started, a Controller error in the major fault level will occur
and operation will stop.
20
NJ-series NJ Robotics CPU Unit User's Manual (W539)