GE GFK-0787B Noise Reduction Machine User Manual


 
5
5-23GFK-0787B Chapter 5 Diagnostics
Manual Output Controls and Diagnostics
Safety systems are often provided with controls for manual trip and manual override.
A manual trip causes the output to assume the alarm condition. For example, a
normally-energized output would be de-energized.
A manual override causes the output to remain in the normal condition. For
example, a normally-energized output is held energized.
These manual controls can be implemented either in hardware, as represented below, or in
software. If the software method is used, the GMR autotest and fault processing operations
are unaffected.
Hardware control usually consists of switch contacts applied to the output circuit, as shown
below for a normally-energized output.
Source
Genius
Block
Source
Genius
Block
Sink
Genius
Block
Sink
Genius
Block
Manual
Override
+24V
System Input
Manual Trip
System Input
Manual
Override
LOAD
+0 VDC
In this circuit, operation of either the trip or override switch can cause no-load faults, state
faults, and autotest faults to be generated. If these manual inputs are wired in the GMR
system, fault reporting is modified to suppress no-load faults and Failed Switch faults. Use of
manual controls does not affect fault reporting for Short Circuit, Overtemperature, Overload,
or Discrepancy faults.