View single post by slychiu
 Posted: Sunday Jul 8th, 2018 09:09 am
 PM  Quote  Reply  Full Topic 

Joined: Saturday Apr 29th, 2006
Location: Singapore
Posts: 4226

  back to top

Water Leakage can be detected by connecting the Water Leakage Detection cable WA01-0043 (purchased separately by meters). The WD1 and WD2 Inputs on MSM01 allow 2 water leakage cables to be connected, eg to the ceiling and floor water collection trays. Map the Water Leakage Input 1 or 2 to a Sensor Register.

WA01-0043 Water Leak Detection cable

In the above screenshot Water Leak Input 1 is mapped to Sensor 3 in CM9001-EMS and Water Leak Input 2 is mapped to Sensor 4 in CM9001-EMS
The cable in dry state has a high resistance. When the cable is wet the resistance drops corresponding to the degree of immersion. The cable resistance is inversely proportional to the Sensor value (0 to 255). For open circuit (Infinite resistance), the sensor value is 0 (or close to 0). when the resistance decreases, the Sensor value increases. A threshold can be set in the Sensors screen of CM9001 so that when the sensor value exceeds the threshold, the assigned Virtual Input is activated, thus triggering the associated alarm.
For example, if the sensor value is 40 units when the cable is wet, the sensor setpoint can be set to 20. The setpoint for water leak input 1 is in Counter 3. This setpoint can be changed in KP04A

Detection of Water Leakage Cable Break
It is possible to trigger a Zone Trouble alarm if the water leak detection cable is broken or not connected. This is achieved by connecting the  100 Kohms (supplied with the cable) at the far end of the cable. Make sure that the resistor with the cable does not get wet. The principle of operation is similar to the End-of-line resistor in CM9001 Inputs/Zones, where CM9001 is able to trigger a Zone Trouble alarm if the end of line resistors are installed and there is a cable break. For water leak cable break detection, only 1 EOL resistor (100K) is required (without the series resistor). This is a different value from that used in the double EOL resistors in CM9001.
If the 100K End-of-line resistor is connected at the end of the dry cable, the sensor value should be around 60 counts. If the cable is wet the sensor reading should be 100 or more. Hence the Setpoint for water detection should be around 80 counts. The threshold for cable break should be around 30 counts (midway between 0 and 60). To set this, go to Comfort Registers > Sensors and select the Sensor assigned to the water leakage detector ie Sensor 3 and 3 (for WD Input 1 and 2 respectively). In Scaling Type, select “Residual Offset”, and enter the value of 30 in the Scaling factor. See screenshot below. This has already been set up in the defmsm.cctx template. Write to MSM01, and test that when the cable is disconnected, a Zone Trouble alarm is triggered.  The Zone Trouble alarm can be programmed to dial to any combination of the 16 phone numbers.

Last edited on Sunday Jul 8th, 2018 09:12 am by slychiu

 Close Window