System Considerations; Ground Network Considerations - Allen-Bradley 1395 Troubleshooting Manual

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System Considerations

Ground Network
Considerations
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The set-up parameters for the second and third trends will be identical to the
first to allow real time comparison between the data samples. The necessary
set-up parameter values for Trend File 2 and 3 are:
Parameter 904 "Trend Logic Val" = 00000000000100000 (bit sel)
Parameter 920 "Tr2 Opnd Param X" = 101 (test operand)
Parameter 921 "Tr2 Opnd Param Y" = 904 (constant operand)
Parameter 922 "Tr2 Operator" = .EQ. (operator for bit 5)
Parameter 923 "Tr2 Sample Rate" = 10 (sample rate in sec)
Parameter 924 "Tr2 Post Samples" = 0 (# samples after trig)
Parameter 925 "Tr2 Mult Trigger" = OFF (single shot)
Parameter 926 "Tr2 Enable" = ON (enable trend)
Parameter 904"Trend Logic Val" = 00000000000100000 (bit sel)
Parameter 930 "Tr3 Opnd Param X" = 101 (test operand)
Parameter 931 "Tr3 Opnd Param Y" = 904 (constant operand)
Parameter 932 "Tr3 Operator" = .EQ. (operator for bit 5)
Parameter 933 "Tr3 Sample Rate" = 10 (sample rate in sec)
Parameter 934 "Tr3 Post Samples" = 0 (# samples after trig)
Parameter 935 "Tr3 Mult Trigger" = OFF (single shot)
Parameter 936 "Tr3 Enable" = ON (enable trend)
When the fault occurs the sampled data will be output to the analog
channels. Analog Channel 1 will output the velocity feedback, analog
channel 2 will output armature current feedback, and analog channel 3 will
output field current feedback The data can also be examined with the
programming terminal.
When applying the 1395 Drive in system applications, certain precautions
and good design practices should be followed. Special ground
considerations must be taken to provide a low noise environment that
reduces Drive malfunctions and enhances the reliability of the system.
Likewise the Drive should be kept clean and free from foreign material
contamination. Air flow around the Drive and system cabinet should not be
restricted, but be allowed to circulate clean air from proper cooling. By
following these considerations system malfunctions can be minimized.
Several ground connections are provided on the 1395 controller and each
serves a specific function. Overall the grounding should be configured in a
Star type arrangement. All devices in the system should be directly tied to a
central low impedance point source. Avoid daisy chained ground
connections where ground connections are run from device to device before
it is connected to the low impedance source. For specific grounding
information for your drive, refer to the Hardware and Installation chapters
in the 1395 Installation Manual.
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