Owner's Manual

Multi-Zone Gas Monitors
P/N: 3015-5074 Rev 11 23
Figure 2-12. Optional Dual 4-20 mA DC Output Board and Connector
2.10. Connecting External Alarms
2.10.1. Overview
The MZ monitor includes four SPDT relays whose contacts are rated 2 A at 250 VAC (inductive) and 5 A at
250 VAC (resistive). These relays are used for the connection of external alarm devices that are activated
when the relay is energized. The relays are factory assigned to energize under the following conditions:
Relay #1 Leak Alarm Point 100 ppm
Relay #2 Spill Alarm Point 300 ppm
Relay #3 Evacuate Alarm Point 500 ppm
Relay #4 Fault System Fault Event
2.10.2. Connection
Use the conduit or any of the remaining service knockouts to gain cable access to the interior of the monitor.
Locate the relay connector (see Figure 2-3 on page 13) and remove it from the circuit board. Secure the
leads to the connector orienting them as shown in the diagram below. When you are through securing the
connections, carefully plug the connector back onto the circuit board.
Figure 2-13. MZ Monitor Relay Connector
Each relay may be connected as normally open (NO), or normally closed (NC). The relay contacts are
rated 2 A at 250 VAC (inductive) and 5 A at 250 VAC (resistive).
Power for the alarm devices connected to the relay contacts may be supplied by an external 24 VDC
power source or the monitor’s AC input terminals. In the first wiring diagram, power to this device is being
tapped off the monitor’s AC input. In the second wiring diagram, power is supplied from an external
power source.