IDEC MicroSmart - Manual (Page 111)

3: I NSTALLATION AND W IRING
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Slim Type CPU Module (DC Power)
Power Supply Voltage
The allowable power voltage range for the slim type MicroSmart CPU module is 20.4 to 26.4V DC.
Power failure detection voltage depends on the quantity of used input and output points. Basically, power failure is
detected when the power voltage drops below 20.4V DC, stopping operation to prevent malfunction.
A momentary power interruption for 10 ms or less is not recognized as a power failure at the rated voltage of 24V DC.
Inrush Current at Power-up
When the slim type CPU module is powered up, an inrush current of a
maximum of 50A flows.
Power Supply Wiring
Use a stranded wire of UL1015 AWG22 or UL1007 AWG18 for power
supply wiring. Make the power supply wiring as short as possible.
Run the power supply wiring as far away as possible from motor lines.
Grounding
To prevent electrical shocks, connect the terminal to a proper ground
using a wire of UL1015 AWG22 or UL1007 AWG18. The grounding also
prevents malfunctioning due to noise.
Do not connect the grounding wire in common with the grounding wire of
motor equipment.
Caution
• Use a power supply of the rated value. Use of a wrong power supply may cause fire hazard.
• The allowable power voltage range for the slim type
MicroSmart CPU module is 20.4 to 26.4V
DC. Do not use the MicroSmart on any other voltage.
• If the power voltage turns on or off very slowly between 10 to 15V DC, the
MicroSmart may run
and stop repeatedly between these voltages. If failure or disorder of the control system, damage,
or accidents may be caused, provide a measure for prevention using a voltage monitoring circuit
outside the
MicroSmart.
• Use an IEC 60127-approved fuse on the power line outside the
MicroSmart . This is required
when equipment containing the MicroSmart is destined for Europe.
24V DC
+ –
+
–