Emerson MRLDS-250 Operating instructions

MRLDS-250 Infrared Gas Detector
Installation and Operation Manual
026-1315 Rev 4

Emerson
1065 Big Shanty Road NW, Suite 100
Kennesaw, GA 30144 USA
Email Solutio[email protected]m
770-425-2724 • www.emerson.com

MRLDS-250 Infrared Gas Detector I&O Manual Table of Contents • v
Contents
1 INTRODUCTION.............................................................................................................................. 1
1.1. OVERVIEW ........................................................................................................................................ 1
1.2. DETECTION OPTIONS ........................................................................................................................ 1
1.2.1. Broadband vs. Gas Specific...................................................................................................... 1
1.2.2. Broadband Gas Detection ........................................................................................................ 1
1.2.3. Detecting Specific Gases .......................................................................................................... 2
1.3. REMOTE CONTROLLER OPTIONS....................................................................................................... 3
1.4. PARTS LIST ....................................................................................................................................... 3
1.5. SPECIFICATIONS ................................................................................................................................ 4
2 MOUNTING THE GAS DETECTOR............................................................................................. 5
2.1. WARNINGS AND PREREQUISITES ...................................................................................................... 5
2.2. MOUNTING LOCATIONS .................................................................................................................... 5
2.2.1. General Placement Guidelines................................................................................................. 5
2.2.2. Machinery Rooms..................................................................................................................... 5
2.2.3. Refrigerated Spaces.................................................................................................................. 6
2.2.4. Chillers ..................................................................................................................................... 6
2.3. MOUNTING PROCEDURE ................................................................................................................... 6
3 WIRING AND CONFIGURATION ................................................................................................ 8
3.1. OVERVIEW ........................................................................................................................................ 8
3.2. WIRING SUPPLY POWER (24VAC OR 24VDC) ................................................................................ 8
3.3. WIRING ALARM OUTPUT (ANALOG SIGNAL) ................................................................................... 9
3.4. WIRING THE DIGITAL ALARM OUTPUT RELAY ................................................................................ 9
3.5. MODBUS NETWORK CONFIGURATION ......................................................................................... 10
3.6. FINISH INSTALLATION..................................................................................................................... 11
4 OPERATION AND STABILIZATION ......................................................................................... 12
4.1. POWER UP AND WARMUP............................................................................................................... 12
4.2. STABILIZATION ............................................................................................................................... 12
4.3. PERFORM A MANUAL ZERO............................................................................................................ 12
4.4. ALARMS .......................................................................................................................................... 12
4.5. GAS DETECTOR FAULTS ................................................................................................................. 13
4.5.1. Overview................................................................................................................................. 13
4.5.2. Non-Critical Faults ................................................................................................................ 13
4.5.3. Critical Faults ........................................................................................................................ 13
5 CONFIGURE THE GAS DETECTOR ......................................................................................... 14
5.1. USER INTERFACE OVERVIEW.......................................................................................................... 14
5.2. SETTING PARAMETERS.................................................................................................................... 14
5.2.1. Overview................................................................................................................................. 14
5.2.2. Configuration Parameters...................................................................................................... 14

vi • Table of Contents 026-1315 Rev 4
5.3. COMPLETING SETUP ....................................................................................................................... 19
6 FUNCTIONAL TESTS AND ADJUSTMENTS........................................................................... 20
6.1. INTRODUCTION ............................................................................................................................... 20
6.2. BUMP TESTING VS. ADJUSTING DETECTOR RESPONSE .................................................................. 21
6.3. BUMP TESTING ............................................................................................................................... 21
6.4. ADJUSTMENT USING CALIBRATION GAS ....................................................................................... 22
7 MODBUS COMMUNICATIONS.................................................................................................. 24
7.1. INTRODUCTION ............................................................................................................................... 24
7.2. COMMUNICATIONS SETTINGS......................................................................................................... 24
7.3. ANALOG INPUT REGISTERS ............................................................................................................ 24
7.4. ANALOG OUTPUT REGISTERS......................................................................................................... 25
7.5. INPUT STATUS FLAGS..................................................................................................................... 26
7.6. OUTPUT STATUS FLAGS ................................................................................................................. 26
8 TROUBLESHOOTING .................................................................................................................. 27
8.1. FAULT CODES................................................................................................................................. 27
8.2. DIAGNOSTIC ATTRIBUTES (P.-18) .................................................................................................. 28
8.3. RESETTING THE MRLDS-250 TO DEFAULT VALUES..................................................................... 29
8.4. OTHER SYMPTOMS ......................................................................................................................... 29
9 REPLACEMENT PARTS AND ACCESSORIES ....................................................................... 30

Overview Introduction • 1
1 Introduction
1.1. Overview
The MRLDS-250 NDIR (non-dispersive infrared) is a
state-of-the-art fixed gas detector that can detect a
wide range of refrigerant gases. The MRLDS-250 can
be used on a stand-alone basis or integrated into
controls or a Building Management System (BMS).
The MRLDS-250 can be used in locations that require
continuous monitoring and to add gas detection
solutions to an existing system.
Figure 1-1 - MRLDS-250 Components
1.2. Detection Options
1.2.1. Broadband vs. Gas
Specific
The MRLDS-250 NDIR refrigerant gas detectors are
available in two versions: broadband and gas-specific.
1.2.2. Broadband Gas Detection
The broadband gas detector (P/N 809-0030) is used as
a general purpose gross leak detector and is factory
tested and certified. It is shipped from the factory with
accuracy as shown in Table 1-1 (gas dependent). If
more accurate detection is needed, gas specific
versions are available, which are factory certified and
calibrated to the target refrigerant.
The broadband gas detector combines refrigerants
into 4 groups shown in Figure 1-2. Measurement
performance is based on an average response profile
for all of the gases within the group.
Table 1-1 Broadband Gas Groups
Group#
Value
for
Param
111
Refrigerant
As
Shipped
Accuracy
1P.-11 = 1
R134a ±25%
R404a ±35%
R407a ±25%
R407c ±20%
R407f ±20%
R410a ±20%
R427a ±15%
R452B ±40%
R507 ±35%
HFO1233ZD ±35%
2P.1-11 = 2
R448A ±40%
R449A ±40%
R422a ±25%
R422d ±20%
HFO1234YF ±25%
HFO1234Ze ±25%
R452A ±25%
R513A ±35%
R514A ±20%²
3P.-11 = 3 R22 ±25%
4P.-11 = 4 R32 ±35%

NOTE: Greater accuracy may be
achieved through the use of
calibration gas and the adjustment
procedure detailed in Section 6,
Functional Tests and Adjustments.
2 • MRLDS-250 Infrared Gas Detector I&O Manual 026-1315 Rev 4
1See Section 5, Configure the Gas Detector for Information on Parameter 11 and other configuration
instructions.
Figure 1-2 - Broadband Gas Groups 1-4

Detection Options Introduction • 3
1.2.3. Detecting Specific Gases
Each gas-specific gas detector is shipped factory calibrated to its specific target refrigerant. Refer to Figure 1-3
and Table 1-2.
Table 1-2 Gas-specific Detector Measurement Performance
Part Number Refrigerant1Accuracy
809-0031 R22 ±5%
809-0034 R404a ±5%
809-0035 R407a ±3%
809-0040 R422d ±5%
809-0041 R448A ±5%
809-0042 R449A ±5%
809-0043 R513A ±5%
809-0044 R507 ±5%
1See Section 5, Configure the Gas Detector for Information on Parameter 11 and other configuration
instructions.
Figure 1-3 - Gas-Specific MRLDS-250 Gas Detectors
NOTE: Emerson recommends not 
re-calibrating gas-specific detectors in
the field to a new target gas; purchase a
new gas-specific detector instead. In the
event you prefer not to purchase a new
gas-specific detector, use optional
calibration instructions in Chapter 6 for increased
accuracy when detecting a new target that is different
from the “as shipped” target gas. Refer to the example
in Table 1-3.

Table 1-3 Changing Gas Types and Accuracy
As Shipped
Part number 809-0031 (R22)
is factory calibrated to R22.
Changed Gas
Type
(Reduced
Accuracy)
The gas detector may be
changed to respond to any of
the other listed refrigerants
(see parameter P.-11, in
Section 5.2., Setting
Parameters). If changed, the
gas detector will have a lower
accuracy for the target
refrigerant (without
calibration).
Optional
Recalibration
(For
Improved
Accuracy)
By applying calibration gas
containing the new target
refrigerant, and via the routine
described in Section 6.4., the
gas detector may then be
adjusted to respond with the
calibrated accuracy as shown
in Table 1-2 for the new target
refrigerant.
4 • MRLDS-250 Infrared Gas Detector I&O Manual 026-1315 Rev 4
1.3. Remote Controller
Options
The MRLDS-250 can connect to any controller
through the standard analog output (voltage and
current; see Table 1-4 for options), the standard alarm
relay, or the digital Modbus RTU communications
interface.
1.4. Parts List
Table 1-4 shows a list of components that are
available.
Table 1-4 Parts List
Part
Number Description
809-0030 MRLDS, Broadband
809-0031 MRLDS, Calibrated to R22
809-0034 MRLDS, Calibrated to R404A
809-0035 MRLDS, Calibrated to R407A
809-0040 MRLDS, Calibrated to R422D
809-0041 MRLDS, Calibrated to R448A
809-0042 MRLDS, Calibrated to R449A
809-0043 MRLDS, Calibrated to R513A
809-0044 MRLDS, Calibrated to R507
603-1100 Splash Guard
026-1315 Installation and Operation 
Manual