18
Industrial Computers for Hazardous Locations
Rockwell Automation Publication 6181X-IN001C-EN-P - April 2011
Application Information
The circuit parameters of associated field-wired apparatus for use in hazardous locations shall be
coordinated with the host product such that their combination remains nonincendive. The
6181X computers and the USB peripheral devices shall be treated in this manner.
The circuit parameters of the 6181X computers’ USB ports are indicated in the previous table.
The 6181X computers provides four separately powered USB ports.
The USB peripheral devices and their associated cabling shall have circuit parameters with the
limits given in the
Control Drawing - Class I Division 2 and Zone 2 Required Circuit
Parameters for USB Peripheral Devices
section table for them to remain nonincendive when
used with the 6181X computers’ USB ports.
For the comparison of
C
a(USB)
, use the capacitance of each individual connected USB peripheral
device,
C
i(peripheral)
, and its associated cable,
C
cable
.
If cable capacitance and inductance are not known, the following values may be used:
C
cable
= 197
µ
F/m (60 pF/ft)
L
cable
= 0.7
µ
H/m (0.20
µ
H/ft)
Apply Power
Both the display and non-display computers have a DC input terminal block for connecting to a
18…32V DC power source.
The DC power option supports operation from safety extra-low voltage (SELV) power source.
The power supply is internally protected against reverse polarity.
A functional ground connection is required for EMC compliance.
ATTENTION:
The computer circuit should have its own disconnect. Use an
uninterruptible power source (UPS) to protect against unexpected power failure
or power surges.
Always shut down the operating system before removing power to minimize
performance degradation and operating system failures.
ATTENTION:
Use an SELV isolated and ungrounded power supply as input
power to the computer. This power source provides protection so that under
normal and single fault conditions, the voltage between the conductors and
Functional Earth/Protective Earth does not exceed a safe value.
