Emerson MRLDS User Manual

“MV” should be entered for sensor inputs that read fault 
status.

Since the output terminals emit one volt for every 250 

ppm of refrigerant detected, the gain for the refrigerant leak 
sensors must be set to 250 and the Offset to 0. 

The sensors configured to detect faults must be given a 

gain of 1000; this way, the REFLECS can be set up to 
alarm whenever it detects a 5000 mV signal.

Locate the screen in the BEC or RMCC where sensor 

alarm set points are specified. This is usually a menu option 
in the Sensors Menu, which may be reached from the Main 
Menu.

The REFLECS should now be capable of interpreting 

the 0-4.8V output voltage as a refrigerant concentration of 
0-1200 ppm and the 5V output voltage as a fault. The de-
sired alarm set points must now be specified. When set up 
correctly, alarms will appear in the REFLECS Alarm log as 
“Hi Sensor” alarms (refer to the REFLECS manual for 
alarm descriptions).

In this field, specify a high alarm setpoint for refriger-

ant leak alarms between 0 and 1200 ppm. For fault status 
alarms, enter a setpoint of 4960 mV (slightly below 5V, as 
a precautionary measure).

The value entered in the Alarms Dly field is the number 

of minutes the sensor reading must be above the 
Alarms:High set point before the REFLECS may generate 
a leak alarm

 When choosing an alarm delay, keep in mind the 

amount of time it takes an IRLDS to complete a sampling 
cycle. For example, a 16-valve IRLDS with 30 second sam-
pling times for each zone takes a total of eight minutes to 
sample all zones. Choosing an alarm delay smaller than the 
IRLDS’s cycle time will cause an alarm to be generated af-
ter only one high reading is taken.

The MRLDS has three LEDs for quick status indica-

tion.

For analog output models, a fault is signaled by setting 

the voltage to 0.5V, which indicates the MRLDS should be 
be replaced. Call the CPC Service Department (770-425-
2724) to verify if the MRLDS unit should be replaced.

If any one or all of the MRLDS sensors encounters a 

problem, the IRLDS application will alarm and all cell 
outputs will show NONE. For details on which individual 
unit is in alarm, go to the MRLDS Gateway and check the 
Status screen on the HHT.

If an MRLDS has lost communication, the input will 

go to 1250 PPM, which should force an alarm if enabled. 
If all MRLDS sensors lose communication, the 16AI will 
go offline. Check the Status screen on the HHT for details.

Green

Lights during normal operation

Red

Flashes at 0.5 Hz during start-up
Turns ON solid if concentration 
reading exceeds 50 ppm

Yellow

Flashes at 0.5 Hz if power sup-
plied is outside set limits
Turns ON solid during other fault 
conditions