Wiring And Configuration; Overview; Wiring Supply Power (24Vac Or 24Vdc) - Emerson MRLDS-250 Installation And Operation Manual

3 Wiring and
Configuration

3.1. Overview

Prior to wiring and configuring the MRLDS-250,
ensure the following conditions have been met:
• MRLDS-250 backplate is mounted in an appropriate
location.
• The cover panel is removed.
If the cover panel was reattached after mounting,
open the gas detector enclosure by pressing the top
latch with a suitable screwdriver or other flat blade.
With the top latch depressed pull the housing apart by
grasping the sides and pulling straight out. Align and
press together to close.
Figure 3-1 Terminal Blocks and Cable Glands
NOTE: The pre-installed cable gland (left) and
the optional cable on the gland (right) have a
1/4 cable capacity (each).
NOTE: Install the optional cable gland in the
right side of the base unit if needed. Otherwise,
install the blanking plug that is included in the
mounting kit.
Overview
3.2. Wiring Supply Power
(24VAC or 24VDC)
CAUTION: Incorrect wiring may permanently
damage the gas detector and void the warranty.
Double check all terminations before applying
power.
Either 24VAC or 24VDC may be used to power
the MRLDS-250. Connect wiring to the appropriate
terminal locations (see ). Use two wires, between 14
and 22 AWG. Refer to Figure 3-2 for (AC wiring left)
or DC wiring (right).
Figure 3-2 Supply Power Wiring Options
Power Pin Label
Option
24 VAC
1 L
2 N
24 VDC 3 +
4 GND
Table 3-1 Power Options and Terminal Block Connections
Wiring Termination
24V AC line
24V AC neutral
24V DC positive
24V DC ground
Wiring and Configuration • 7