Chapter 2
Configuration and Installation
©
National Instruments Corporation
2-3
NI PCI-7342 Hardware User Manual
•
Pollution Degree 2—Normally only nonconductive pollution occurs.
Occasionally, nonconductive pollution becomes conductive because of
condensation.
•
Pollution Degree 3—Conductive pollution or dry, nonconductive
pollution occurs. Nonconductive pollution becomes conductive
because of condensation.
Clean the device and accessories by brushing off light dust with a soft,
nonmetallic brush. Remove other contaminants with a stiff, nonmetallic
brush. The unit
must
be completely dry and free from contaminants before
returning it to service.
You
must
insulate signal connections for the maximum voltage for which
the device is rated. Do
not
exceed the maximum ratings for the device.
Remove power from signal lines before connection to or disconnection
from the device.
Operate this device only at or below the installation category stated in the
specifications. Installation categories are listed below:
•
Installation CAT IV—for measurements performed at the source of the
low-voltage (<1000 V) installation. Examples include electricity
meters, measurements on primary overcurrent protection devices,
and ripple-control units.
•
Installation CAT III—for measurements performed in the building
installation. Examples include measurements on distribution boards,
circuit-breakers, wiring (including cables), bus bars, junction boxes,
switches, socket outlets in the fixed installation, equipment for
industrial use, and some other types of equipment, such as stationary
motors permanently connected to the fixed installation.
•
Installation CAT II—for measurements performed on circuits directly
connected to the low-voltage installation. Examples include
measurements on household appliances, portable tools, and other
similar equipment.
•
Installation CAT I—for measurements performed on circuits not
directly connected to mains
1
. Examples include measurements on
circuits not derived from mains, and specially-protected (internal)
mains-derived circuits.
1
Mains
is defined as the electricity supply system to which the equipment concerned is designed to be connected for either
powering the equipment or for measurement purposes.
