Precaution In Supplying Power To Slave Units - Omron CJ Series Operation Manual

4-4-5 Precaution in Supplying Power to Slave Units

When supplying communications power and I/O power, the allowable currents of cables and connec-
tions, the voltage drop, and the capacity and location of power supplies must be considered.
Allowable Current Restrictions
Do not allow the total current consumption of all Slave Units to exceed the allowable current of the com-
munications cables and connectors. If the allowable current is exceeded, heating or burning may occur.
Branch Line Pressure-welded
Connector (5 A max.)
Master
Unit
Power
supply,
24 VDC
Allowable Currents for Cables
Select the communications cable so that the total current consumption of all Slave Units does not
exceed the allowable current of the cable.
Cable allowable current ≥ I
(For the allowable cable current for "a" in the above diagram)
Allowable Currents for Connectors
There are limits to the allowable current for the communications power supply connectors on the
Master Unit and Repeater Units, Flat Connector Sockets, and Flat Connector Plugs. Do not allow
the current flow where these connectors are used to exceed the allowable current.
Communications power supply
connectors on CJ-Master Units
Communications power supply
connector on Repeater Unit
Flat Connector Socket
Flat Connector Plug
Multi-wiring Connector
Flat Multi-wiring Connector Plug
CJ-series CompoNet Master Unit Operation Manual for NJ-series CPU Unit (Cat. No. W493)
Trunk Line
Pressure-welded
Connector (5 A max.)
Cable
(a)
Slave Unit
Slave Unit
current current
consumption I consumption I
1
+ I + I + · · · · I
1 2 3
Name
CJ1W-CRM21
CRS1-RPT01
DCN4-TR4
DCN5-TR4
DCN4-BR4
DCN5-BR4
DCN4-MD4
DCN4-MR4
Slave Unit
Slave Unit
current
current
consumption I
consumption I
2
3
n
Allowable cur-
Model
rent
5 A (UL rating:
4A)
4 Installation and Wiring
Terminating
Resistor
n
Remarks
Round Cable I, Round
Cable II, Flat Cable I, or
Flat Cable II
Flat Cable I
4
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