Avoiding electrostatic damage, Determining power requirements – Rockwell Automation 1746-NO8V SLC 500 8-Point Analog Output Module/ User Manual User Manual
Page 11
Publication 1746-UM026A-EN-P - September 2003
Installation and Wiring 2-3
Avoiding Electrostatic
Damage
Electrostatic discharge can damage semiconductor devices inside this
module if you touch backplane connector pins. Guard against
electrostatic damage by observing the following precautions.
•
Wear an approved wrist strap grounding device when handling
the module.
•
Touch a grounded object to rid yourself of electrostatic charge
before handling the module.
•
Handle the module from the front, away from the backplane
connector. Do not touch backplane connector pins.
•
Keep the module in its static-shield bag when not in use, or
during shipment.
Determining Power
Requirements
The module receives its power through the SLC 500 chassis backplane
from the +5V dc/+24V dc chassis power supply. The +5V dc
backplane supply powers the SLC circuitry, and the +24V dc
backplane supply powers the module analog circuitry. The maximum
current drawn by the module is shown in the table below.
Add the values shown in the table above to the requirements of all
other modules in the SLC chassis to prevent overloading the chassis
power supply. Refer to your controller’s User Manual for power
supply loading calculations and worksheets.
ATTENTION
!
Electrostatic discharge can degrade performance or
cause permanent damage. Handle the module as
stated below.
Table 2.1 1746-NO8 Backplane Current Consumption
Specification
1746-NO8I
1746-NO8V
Backplane Current Consumption
(maximum)
120 mA at 5V dc
250 mA at 24V dc
120 mA at 5V dc
160 mA at 24V dc
Backplane Current Consumption
(maximum) when Using External
24V dc Power Supply
(1)
(1)
The 1746-NO8I and 1746-NO8V output modules can use an external 24V dc power supply to reduce backplane
loading. To use an external 24V dc power supply, you must set your module’s jumper J4 as indicated in the
following section. To comply with the U.L. regulation, the external power supply must be rated N.E.C. Class 2.
NOTE: The external 24V dc power supply terminal block ground connection (DC COM) is connected to the SLC
power supply ground.
120 mA at 5V dc
0 mA at 24V dc
120 mA at 5V dc
0 mA at 24V dc