National Instruments CFP-RLY-421 Manuale Utente
cFP-RLY-421
10
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•
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.
terminals) with other devices (including other FieldPoint
devices), unless those devices are isolated from human contact.
•
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:
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.
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 backplanes in an area,
position, or cabinet that prevents accidental or unauthorized
access to wiring that carries hazardous voltages.
wiring and connections meet applicable electrical codes and
commonsense practices. Mount backplanes in an area,
position, or cabinet that prevents accidental or unauthorized
access to wiring that carries hazardous voltages.
•
The isolation of the cFP-RLY-421 is certified as
double-insulated for working voltages of 250 V
double-insulated for working voltages of 250 V
rms
. Do not use
the cFP-RLY-421 as the only isolating barrier between human
contact and working voltages of more than 250 V
contact and working voltages of more than 250 V
rms
.
•
Operate the cFP-RLY-421 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.
Pollution Degree 2 means that only nonconductive pollution
occurs in most cases. Occasionally, however, a temporary
conductivity caused by condensation must be expected.
•
Do not operate FieldPoint products in an explosive atmosphere
or where there may be flammable gases or fumes. If you need
to operate FieldPoint products in such an environment, the
FieldPoint products must be in a suitably rated enclosure.
or where there may be flammable gases or fumes. If you need
to operate FieldPoint products in such an environment, the
FieldPoint products must be in a suitably rated enclosure.
•
Operate the cFP-RLY-421 at or below Installation Category II.
Installation 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.
Installation 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.