National Instruments FP-Al-110 用户手册

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页码 20
FP-AI-110 and cFP-AI-110
10
ni.com
working voltages of 250 V
rms
1
. 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.
Never try to use any isolation product between human-accessible 
parts (such as DIN rails or monitoring stations) and circuits that 
can be at hazardous potentials under normal conditions, unless the 
product is specifically designed for such an application, as is the 
[c]FP-AI-110.
Even though the [c]FP-AI-110 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-AI-110. 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-AI-110 as the only isolating barrier 
between human contact and working voltages higher than 
250 V
rms
.
1  
Working voltage is defined as the signal voltage plus the common-mode voltage. 
Common-mode voltage is the voltage of the module with respect to ground.