EMERSON Refrigerant Gas Detector (MRLDS-450) User Guide

EMERSON Refrigerant Gas Detector (MRLDS-450) User Guide

Refrigerant Gas Detector (MRLDS-450) for Machinery Rooms, Cold Rooms and

Freezers

The MRLDS-450 refrigerant gas detector is designed for use in refrigeration applications and may be used as a stand-alone device, or connected to a facility’s building management system (BMS). It enables compliance with refrigerant safety codes (ASHRAE 15 and EN378) and features audible and visual alarms to alert personnel in the event of a refrigerant leak.

Figure 1

1. Safety Instructions

DANGER: The MRLDS-450 is NOT certified or approved for operation in oxygen-enriched atmospheres. Failure to comply may result in severe injury or
death.
WARNING: Use this product ONLY for the purposes and under the conditions listed in the user manual. Failure to comply may result in injury and/or damage
to the product. The MRLDS-450 has not been designed to be intrinsically safe for use in areas classified as being hazardous locations. For your safety, DO NOT use in
hazardous locations. Consult a qualified professional before connecting the MRLDS-450 to devices not mentioned in this manual. Failure to comply may result in injury and/or damage to the product.

WARNING: The gas diffusion path can become occluded (moisture, dust, debris, frozen condensation) over time, resulting in reduced or complete lack of gas detection and alarming function. Routine visual inspection of the gas detector and bump testing are recommended to ensure proper gas detection and alarm function. For information on calibrating the sensor, refer to the Care and Maintenance section of the MRLDS-450 User Manual P/N 026-1316.

CAUTION: Except for the maintenance detailed in this manual, this product should ONLY be opened and/or serviced by authorized personnel. Failure to comply may void the warranty.

CODE COMPLIANCE: Comply with all local and national laws, rules and regulations associated with this equipment. Operators should be aware of the regulations and standards in their industry/locality for the operation of the MRLDS-450.

TECHNICIAN USE ONLY: The MRLDS-450 must be installed by a suitably qualified technician who will install this unit in accordance with these instructions and the standards in their particular industry/locality. This document is only intended as a guide and the manufacturer bears no responsibility for the installation or operation of this unit. Failure to install and operate the unit in accordance with these instructions and with industry guidelines may cause serious injury or death and the manufacturer
will not be held responsible in this regard.

2. Component Overview

Figure 2

                  #

|

  Component Description

---|---
                  1|   M16 Cable Glands (x6)
                  2|   Rubber Gasket
                  3|   Internal Alarm Buzzer
                  4|   Power Connections (x2)
                  5|   Digital Connection (Modbus)
                  6|   Analog Connection
                  7|   Tactile Switch #1
                  8|   Ribbon Cable Connection (To Sensor)
                  9|   Tactile Switch #2
                 10|   Relay 3 Connection (FAULT)
                 11|   Relay 2 Connection (HIGH)
                 12|   Relay 1 Connection (LOW)
                 13|   Magnetic (Mag) Switch #1
                  14|   Magnetic (Mag) Switch #2
                 15|   M20 Cable Glands (x2)

3. Product Specifications

cm)
  Alarm Delay|   Configurable (0 to 15 minutes)
  Inputs|   Tactile Switches (x2), Magnetic Switches (x2)
  Outputs|   Analog Output: 4 to 20mA (default), 0 to 5V, 0 to 10V, 1 to 5V or 2 to 10V
  Bluetooth®|   Bluetooth® Low Energy, BLE 4.2
  Modbus|    Connection: RS-485 terminal block
Baud Rate: 9,600 or 19,200 (default)
Data Bits: 8
Parity: None, Odd, or Even (default)
Stop Bits: 1 (default) or 2
Retry Time: 500 ms (minimum)
  Power Supply|   19.5 to 28.5 VDC or 24 VAC ±20%; 4W
  Wiring (Power)|   2-core cable, 16 to 28 AWG
  Wiring (Relays)|   2-core cable, 16 to 28 AWG
  Wiring (Modbus)|   Recommended: Belden 3106A (or equivalent) 3-core, 2 twisted pair +
ground, shielded cable with 120 Ω characteristic impedance,
16 to 28 AWG
  Enclosure|   Material: ABS
Protection: IP66
  Temperature|   Semiconductor: -40°F to 122°F (-40°C to 50°C)
Electrochemical: Ranges vary by gas type and / or concentration,
see the MRLDS-450 user manual (P/N 026-1316) for a full list of
temperature ranges.
Infrared: -40°F to 122°F (-40°C to 50°C)
Catalytic Bead: -40 to 122°F (-40°C to 50°C)
  Humidity|   5 to 90% RH, non-condensing
  Pressure|   23.6 to 32.5”Hg (800 to 1,100 mbar)
|   0 to 6,560’ (3,000 m) altitude

Table 2 – Product Specifications

4. Installation

IMPORTANT: The manufacturer of this product requires that a bump test or calibration be performed following installation to verify installation to verify instrument functionality

STEP 1: Mount Gas Detector & Remove Lid

1. Mount the MRLDS-450 according to the product dimensions, maximum wiring lengths, and following considerations:
   • Environment: the full range of environmental conditions when selecting a location.
   • Application: the specifics of the application (possible leaks, air movement/draft, etc.) when selecting a location.
   • .Accessibility: the degree of accessibility required for maintenance purposes when selecting a location.
   • Target Gas: the specific gravity of the target gas when selecting the height of the instrument.

2. Using a 5/32” (4mm) hex key/allen wrench (not included), remove the lid and disconnect the ribbon cable from the base.

3. Set the lid and rubber gasket aside to be reinstalled later.

STEP 2: Wire Connections

WARNING: Ensure that all wiring connections are made BEFORE applying power.

WARNING: Relays are rated for 0 to 30V. DO NOT apply main power onto these relays.

IMPORTANT: Cable glands are meant to accommodate one cable. DO NOT use cable glands for more than one cable.

*IMPORTANT: The MRLDS-450 has a jumper on the analog output. This jumper MUST be removed to use the analog 4-20mA
output signal. If the jumper is removed AND the 4-20mA output signal is not used, the unit will go into fault (refer to the
026-4421 Technical Bulletin for more information).

1. Locate connections (Power, Analog, Modbus, Relays) and remove terminal blocks from the PCBA.
   

2.  Remove plugs from the corresponding M16 cable glands and pass the cable through the opening.

3. Secure wires in each terminal block and, pressing firmly, reinstall the terminal block in the PCBA.

4. Remove all excess cable from the housing before firmly securing the cable glands.

STEP 3: Reinstall Sensor and Connect Lid

CAUTION: DO NOT leave excess cable inside of the gas detector housing. Failure to comply may result in damage to the product.

IMPORTANT: To achieve proper seal in the IP66 enclosure, the lid screws should be torqued to 15 to 20 lbf in (1.5 to 2.0 Nm).

1. Reinstall the rubber gasket. Ensure that it is correctly seated by placing the side with two grooves face down and the edge with two bumps on the top.
   
   Figure 4

2. Reconnect the ribbon cable from the sensor to the PCBA as shown:
   

3. Ensure no cables are interfering with the sensor module and close the lid.

4. Using a 5/32” (4 mm) hex key/allen wrench, tighten the lid screws in an X tightening pattern:
   
   Figure 6

5. MRLDS-450 Network Setup for Site Supervisor and E2

For Modbus end-of-line termination, use 150Ω ohm resistor or termination block P/N 537-2711. Do not use MRLDS 120Ω ohm
on-board termination with Site Supervisor or E2.

MPORTANT:

• For 24 VAC installations sharing a transformer in a daisy-chain configuration, the neutral polarity must be maintained for all instruments.
• 24 VAC power polarity must not be reversed.
• For a more robust system, a dedicated transformer for each MRLDS is recommended to prevent damage caused by wiring errors.
• Fasten terminal screws.

5a. Site Supervisor Device and COMM Setup

Figure 7

5b. E2 Device and COMM Setup

                                        Figure 8

6. Connect MRLDS-450 to MRLDS-400 Series App (User Discretion)

The MRLDS-450 uses a smartphone application to allow users to interface with the gas detector.

IMPORTANT: Default alias, passkey, and unlock code can be changed via the MRLDS-400 Series App’s configuration menu.

1. Enable Bluetooth® discovery by tapping MAG#1 for 1 second. (After 10 seconds, the device will indicate that it is discoverable with audible heartbeat until it has been paired, discovery has timed-out or has been canceled.)
2. Launch the MRLDS-400 App and click the Bluetooth® icon at the bottom of the screen to initiate a scan.
3. Select the instrument (default is 18TMAE) from the list of available gas detectors.
4. When prompted, enter the passkey (default is 123456).
5. Go to Configure tab to set up the device. When prompted, enter unlock code to access device configuration (default is 1234).
   

|

    APP DESCRIPTION

---|---

1

|   Main Menu (App Settings)

2

|   Status (Gas Concentration)

3

|

  Calibrate (Calibration/Bump Test)

4

|   Details (Instrument Information)

5

|   Disconnect Bluetooth®

6

|   Restart Connected Device

7

|   Test Mode (LED/Buzzer/Relays/Analog Output)

8

|   Device Configuration

9

|   Logs

6. Operation Overview

7. Part Number and Ordering Information

MRLDS-450 Accessories

Scan the QR code to download the full user manual P/N 026-1316.
*Refer to the 026-4421 Technical Bulletin for more information.
For Technical Support call 770-425-2724 or email
ColdChain.TechnicalServices@Emerson.com

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