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 Table 3-1. 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
Option
1
24 VAC
2
3
24 VDC
4
Table 3-1 - Power Options and Terminal Block
Connections
Wiring
Label
Termination
L 24V AC line
24V AC
N
neutral
24V DC
+
positive
24V DC
GND
ground
Wiring and Configuration • 9