Emerson MRLDS-250 - Resetting the Mrlds-250 to Default Values; Other Symptoms; S Ettings

Resetting the MRLDS-250 to Default Values Troubleshooting • 29
8.3. Resetting the MRLDS-
250 to Default Values
The gas detector may be reset to its default state, if
needed, to aid in troubleshooting. All settings,
including alarm setpoint, gas adjustments, selected
gas curve, calibration data, Modbus address, etc.
revert to specific default values after a reset. The
broadband sensor option (P/N 809-0030) resets to gas
group 1. Gas specific products (P/Ns 809-0031 to 
809-0044) are reset to the R134a gas curve.
NOTE: Calibrations on either gas-specific or
broadband models are lost after a reset. This returns
the gas detector to an uncalibrated condition. See
parameter P.-17 for information on how to recalibrate
the gas detector.
NOTE: Before performing this
operation, it is advisable to write
down
all the parameter settings so
they can be re-programmed.
Table 8-3 - Resetting MRLDS-250 to Default Values
Step Description
1 Access diagnostics menu P. - 1 8 .
2
Press and hold both the UP and
DOWN buttons for 5 seconds. Th is
will cause the following to occur:
• All the LED segments will then
light for 3 seconds.
• The gas detector resets to the
default settings.
• The gas detector beeper sounds
for 3 seconds.
3
After 3 seconds, the user is
returned to the parameter list at
parameter P. - 1 8 .
4
The gas detector may now be 
re-programmed for further
troubleshooting if needed.
8.4. Other Symptoms
Other common wiring problems can also cause the gas
detector to malfunction. Check below for additional
conditions that will cause gas detector issues.
Displays the elapsed time (in
days) from the last gas
adjustment or test. This value
is automatically reset to 0000
after completing a gas
adjustment via Test Mode 
P. - 1 7 . (Note that the new
adjustment is stored using
the Enter button.) The value
may be reset to 0000 by
pressing the ENTER button.
Reserved
:
Displays the sensor
temperature in °C.
Displays the sensor’s
approximate rate of
temperature change per half
minute interval (°C change
over 30 seconds).
Reserved:
Attribute Description
Table 8-2 - Diagnostics Attributes
Symptom Possible Cause(s)
Green
power
LED off
Check power supply. Check
Wiring.
Table 8-4 - Other Symptoms and Possible Causes