User Guide

Table Of Contents
Single Zone Gas Monitor
P/N: 3015-4256 Rev 10 13
CAUTION: Drilling holes in the SZ enclosure may damage the unit and will void the
warranty. Please use knockouts provided for electrical connections.
2.7. Connecting External Alarms
2.7.1. Overview
The SZ 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
NOTE: Alarm points of relays #1, #2, and #3 are set using the monitor’s LEAKLVL,
SPILLLVL, and EVACLVL function screens (page 21).
2.7.2. Connection
Use any of the service knockouts to gain cable access to the interior of the monitor. Locate the External
Alarm Relay Connector (page 10). Secure the leads from the external alarm device and its power source
to the connector as shown in the diagram below.
Figure 2-7. External Alarm 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 V DC
power source or the monitor’s AC input terminals.
In Figure 2-8, power to this device is being tapped off the monitor’s AC input. In Figure 2-9, power is
supplied from an external power source