National Instruments cFP-PWM-520 User Manual
Page 10
FP-PWM-520 and cFP-PWM-520
10
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Even though the [c]FP-PWM-520 is designed to handle
applications with hazardous potentials, follow these guidelines to
ensure a safe total system:
•
There is no isolation between channels on the
[c]FP-PWM-520. If a hazardous voltage is present on any
channel, all channels are considered hazardous. Make sure that
all other devices and circuits connected to the module are
properly insulated from human contact.
•
Do not share the external supply voltages (the V and C
terminals) with other devices (including other FieldPoint
devices), unless those devices are isolated from human contact.
•
For Compact FieldPoint, you must connect the protective earth
(PE) ground terminal on the cFP-BP-x backplane to the system
safety ground. The backplane PE ground terminal has the
following symbol stamped beside it:
. Connect the
backplane PE ground terminal to the system safety ground
using 14 AWG (1.6 mm) wire with a ring lug. Use the 5/16 in.
panhead screw shipped with the backplane to secure the ring
lug to the backplane PE ground terminal.
•
As with any hazardous voltage wiring, make sure that all
wiring and connections meet applicable electrical codes and
commonsense practices. Mount terminal bases and backplanes
in an area, position, or cabinet that prevents accidental or
unauthorized access to wiring that carries hazardous voltages.
•
Do not use the [c]FP-PWM-520 as the only isolating barrier
between human contact and working voltages higher than
250 V
rms
.
•
Operate the [c]FP-PWM-520 only at or below Pollution
Degree 2. Pollution Degree 2 means that only nonconductive
pollution occurs in most cases. Occasionally, however, a
temporary conductivity caused by condensation must be
expected.
•
Operate the [c]FP-PWM-520 at or below Measurement
Category II. Measurement Category II is for measurements
performed on circuits directly connected to the low-voltage
installation. This category refers to local-level distribution,
such as that provided by a standard wall outlet.