©
National Instruments Corp.
9
FP-RLY-422
NO and NC. The indicators show which terminal is connected
to I.Com.
Isolation and Safety Guidelines
Caution
Read the following information before
attempting to connect ANY circuits that may contain
hazardous voltages to the FP-RLY-422.
This section describes the isolation of the FP-RLY-422 and its
compliance with international safety standards. The outputs are
isolated from the backplane of the terminal base with an isolation
barrier designed and tested to protect against fault voltages of up to
3000 Vrms. In addition, the FP-RLY-422 provides double
insulation (compliant to UL and IEC safety standards) for
working common-mode voltages of 250 Vrms. Safety standards
(such as those published by UL and IEC) require the use of double
insulation between hazardous voltages and any human-accessible
parts or circuits. You should never attempt to use any isolation
product between human-accessible parts (such as DIN rails or
monitoring stations) and circuits that may be at hazardous
potentials under normal conditions, unless the product is
specifically designed (as the FP-RLY-422 is) for such an
application.
Even when a product like the FP-RLY-422 is used in applications
with hazardous potentials, follow these guidelines to ensure a safe
total system:
•
The safety isolation of the FP-RLY-422 is from input to output,
not between channels on the same module. If any of the
channels on a module are wired at a hazardous potential,
ensure that all other devices or circuits connected to that
module are properly insulated from human contact.
•
Do not share the external supply voltages (V and C on the
terminal base) with other devices (including other FieldPoint
devices) unless those devices are also isolated from human
contact.