Specifications

Multi-Zone Gas Monitors
22 P/N: 3015-5074 Rev 10
2.9.2. 4-20 mA DC Connections
External devices are connected to the MZ monitor using a shielded dual twisted pair cable. Use any of the
remaining service knockouts to gain access to the interior of the monitor. Locate the dual 4–20 mA DC
output connector (see below) and remove it from the circuit board. Secure the wire leads to the connector
orienting them as shown in the diagram below. Check to make sure the polarity matches the wiring at the
external device. When you are through securing the connections, carefully plug the connector back onto the
circuit board.
NOTE: The ground connections of the 4-20 mA DC output connector are common.
NOTE: The 4-20 mA DC output connector are SIGNAL OUT ONLY. DO NOT APPLY
POWER.
NOTE: It is highly recommended that a current loop isolator is used when connecting to
the 4-20 outputs. Bacharach recommends the “Dataforth DSCL 21 Loop powered isolator
DIN mount.” More detailed information can be found at www.dataforth.com.
NOTE: When one or both current loop outputs are not used, install a jumper wire between
the ground and the unused loop terminal(s) to prevent the system from generating a
current loop fault.
Figure 2-11. Optional Dual 4-20 mA DC Output Board for the MultiZone
CAUTION: The loop outputs have isolated grounds. Therefore the cable shield should be
terminated at the receiver and not the MZ monitor. The signal for both current loops must
be returned to the MZ monitor.