Emerson M21 Carbon Monoxide Alarm User Manual


 
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MAN-0076 Rev 05 Millennium II
December 07, 2012
Net Safety Monitoring Inc
2.1.6 Remote Reset
If the alarm relays are configured for latching operation it may be desirable to reset latched alarms from a remote
location. In this case a normally open, momentary push-button switch may be connected across terminals RST and
COM.
Figure 10: Remote Reset wiring
2.1.7 Sensor Separation/ Remote mounting of sensor
When necessary to mount sensor remotely (separated from transmitter) by way of junction box and conduit, it is
important that the installer follow the necessary requirements and guidelines relating to sensor separation and cable
selection. See Figure 11 for typical remote mounting of sensor. Also refer Section ‘2.1.2 Cable choice and guidelines’
for cable selection and wiring guidelines.
When sensors are being mounted remotely, consult the multi-purpose junction box manual (MAN-0081) for wiring
instructions. Always ensure that the transmitter is supplying 10.5 - 32Vdc across the sensor power terminals (Vdc +
and Com (-) ) of Net Safety junction box (JB-MPD-A/S).
The maximum distance between the sensor and transmitter is limited by the resistance of the connecting wiring, which
is a function of the gauge of the wire being used. For effective communication, Net Safety limits the separation
distance between sensor and transmitter to 2000ft using 16 AWG wire. See Appendix B for information on wire gauge
and resistance.
Figure 11: Sensor separation/remote mounting of sensor