CONTREX M-Traverse - Manual (Page 139)

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In addition to the diagnostic and power up tests, M–Traverse has automatic indicators
that alert you when there is a power line failure or EMI noise.
Power Failure
If the AC power line voltage drops below the level that is specified for the M-Traverse,
then “- - - - - 1” will appear in the upper LED display. Check the power line for AC
voltage integrity. Use MV-59 to monitor line notching.
CPU Watchdog Failure
If a CPU watchdog failure occurs, then “- - - - - 2” will appear in the upper LED display.
This failure is generally the result of EMI or high frequency noise on the power or the
signal lines. To prevent these failures:
Ground the chassis and AC power properly.
Only one end of the shield wire in a shielded cable should be attached to
earth ground.
Install a power line filter on the AC line if you suspect there may be AC line
noise.
Isolate the internal signal common (J3 Pin 4) and chassis ground (J2 Pin 1).
Install ARC suppressors on any relay and contactors that are in close
proximity to the M-Traverse.
Keep all signal wires isolated from AC power wires.
Because “- - - - - 2” indicates that the CPU has malfunctioned, it is important to
restore the M-Traverse default memory locations. Run the Clear 7 Power Up
procedure and the M-Traverse will restore the factory default settings and it will also
perform the power up routine. To run the Clear 7 Power Up procedure:
Record the Control Parameters that are unique to your system.
Turn the power to the M-Traverse off.
Turn the power to the M–Traverse on, while simultaneously pressing “Clear”
and “7” on the keypad.
The M-Traverse restores the factory default settings and then performs the
power up routine.
Reenter the Control Parameters that are unique to your system.