Emerson MRLDS-250 Installation And Operation Manual

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

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  Summary of Contents for Emerson MRLDS-250

  • Page 1 MRLDS-250 Infrared Gas Detector Installation and Operation Manual 026-1315 Rev 4...
  • Page 4 Emerson 1065 Big Shanty Road NW, Suite 100 Kennesaw, GA 30144 USA Email SolutionsTechSup@Emerson.com 770-425-2724 • www.emerson.com...
  • Page 5: Table Of Contents

    4.5.3. Critical Faults ........................13 5 CONFIGURE THE GAS DETECTOR ..................14 5.1. U ......................14 NTERFACE VERVIEW 5.2. S ........................14 ETTING ARAMETERS 5.2.1. Overview..........................14 5.2.2. Configuration Parameters...................... 14 MRLDS-250 Infrared Gas Detector I&O Manual Table of Contents • v...
  • Page 6 8 TROUBLESHOOTING ........................27 8.1. F ..........................27 AULT ODES 8.2. D (P.-18) ....................28 IAGNOSTIC TTRIBUTES 8.3. R MRLDS-250 ..............29 ESETTING THE EFAULT ALUES 8.4. O ......................... 29 THER YMPTOMS 9 REPLACEMENT PARTS AND ACCESSORIES ............... 30 vi • Table of Contents...
  • Page 7: Introduction

    Accuracy controls or a Building Management System (BMS). R134a ±25% The MRLDS-250 can be used in locations that require continuous monitoring and to add gas detection R404a ±35% solutions to an existing system.
  • Page 8 Section 6, Functional Tests and Adjustments. See Section 5, Configure the Gas Detector for Information on Parameter 11 and other configuration instructions. Figure 1-2 - Broadband Gas Groups 1-4 2 • MRLDS-250 Infrared Gas Detector I&O Manual 026-1315 Rev 4...
  • Page 9: Detecting Specific Gases

    ±5% Table 1-2 Gas-specific Detector Measurement Performance See 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.
  • Page 10: 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. 4 • MRLDS-250 Infrared Gas Detector I&O Manual 026-1315 Rev 4...
  • Page 11: Specifications

    Specification Description 1.5. Specifications Response T90 < 5 minutes Time, T90 For default values, refer to Section 5.2., Setting -22°F to 104°F  Temperature Parameters. Rating (-30°C to 40°C) 5-90% relative humidity,  Humidity and non-condensing, 0-10,000ft. Specification Description Elevation altitude 24 VDC @ 0.15 A min;...
  • Page 12: Mounting The Gas Detector

    Therefore, it is extremely important to select the gas detector location carefully. Also consider ease of access for maintenance. 6 • MRLDS-250 Infrared Gas Detector I&O Manual 026-1315 Rev 4...
  • Page 13: Refrigerated Spaces

    2.2.4. Chillers The size and nature of the site can help in deciding which method is the most appropriate to use. Locations requiring the most protection in a In the case of small water- or air-cooled enclosed machinery or plant room would be in close proximity chiller units, mount the gas detector to monitor airflow to compressors, pressurized storage vessels, to the extract fans.
  • Page 14 (see Section 3, Wiring and Configuration), carefully snap the cover onto the base unit. Table 2-1 Mounting Procedures Figure 2-2 - Front and Back Views of MRLDS-250 Base 8 • MRLDS-250 Infrared Gas Detector I&O Manual 026-1315 Rev 4...
  • Page 15: Wiring And Configuration

    3.1. Overview detector and void the warranty. Double check all terminations Prior to wiring and configuring the MRLDS-250, before applying power. ensure the following conditions have been met: •MRLDS-250 backplate is mounted in an appropriate location.
  • Page 16: Wiring Alarm Output (Analog Signal )

    An alarm setpoint may be programmed from the front that is proportional to the level of gas detected. panel of the MRLDS-250. When the level of the detected gas exceeds the alarm setpoint, the MRLDS- 250 enters the alarm state. An on-board relay is tied to...
  • Page 17: Modbus Network Configuration

    3.5. MODBUS Network Configuration If your application includes a MODBUS network, make network connections (RS-485 A and RS-485 B) using 18 to 24 AWG shielded twisted pair wires (with 120 ohm characteristic impedance) to terminal block positions 7 and 8 Figure 3-6 noting inverted B (-) and non-inverted A (+) signal connectors per Table 3-4.
  • Page 18: Finish Installation

    The gas detector will snap into position, completing all electrical connections. Ensure the top If the MRLDS-250 is at the end of the RS-485 and bottom snap locks are engaged. network, be sure to set the RS-485 terminator on the printed circuit board (PCB) to IN.
  • Page 19: Operation And Stabilization

    Warmup atmosphere around the gas detector is free of all background On powering up, the MRLDS-250 will sense for the concentrations of refrigerant. presence of gas after an initial warm-up period of two Clean air or nitrogen applied to the to five minutes.
  • Page 20: Gas Detector Faults

    Modbus Modbus registers indicate the fault gas detector: Registers 1. Non-critical 2. Critical Table 4-3 - MRLDS-250 Behavior During a Critical Fault 4.5.2. Non-Critical Faults Non-critical faults typically recover by allowing the gas detector surroundings to stabilize, for example, after a defrost cycle. The gas detector continues to monitor its surroundings during non-critical faults, but may report inaccurate readings.
  • Page 21: Configure The Gas Detector

    XX being the parameter value. Pressing Enter while a parameter is displayed allows the attributes of Figure 5-1 - The User Interface of the MRLDS-250 the parameter to be set. Each Parameter has its own attributes, as shown in the following table. Set the The user interface consists of four pushbuttons, a ...
  • Page 22 This allows power failures to be detected as Table 5-2 - Parameter Numbers, Names, and alarms. NO (default mode) Descriptions Failsafe mode Table 5-2 - Parameter Numbers, Names, and Descriptions 16 • MRLDS-250 Infrared Gas Detector I&O Manual 026-1315 Rev 4...
  • Page 23 Parameter Description Parameter Description Gas Groups / Specific Gas Stop Bits Selection Sets the number of stop bits Selects either gas group number required to match the for broadband operation or controlling communications specific gas name for  equipment (for example, gas-specific mode.
  • Page 24 If no activity occurs for ten minutes, the unit exits the Gas Test Mode Table 5-2 - Parameter Numbers, Names, and Descriptions 18 • MRLDS-250 Infrared Gas Detector I&O Manual 026-1315 Rev 4...
  • Page 25: Completing Setup

    The gas button or 5 seconds to exit the Parameter list: detector is now actively monitoring its surroundings. NOTE: If no buttons are pressed for two minutes, the MRLDS-250 exits setup mode automatically. Completing Setup Configure the Gas Detector • 19...
  • Page 26: Functional Tests And Adjustments

    Safe work procedures including the manufacturer’s recommendation. calibration policies are best determined by company policy, industry standards, and local codes. 20 • MRLDS-250 Infrared Gas Detector I&O Manual 026-1315 Rev 4...
  • Page 27: Bump Testing Vs. Adjusting Detector Response

    Monitor the LED • For bump test or calibration, the display reading. Refer to the Section MRLDS-250 should be powered up and fully 1.5., Specifications for acceptance stabilized (see Section 4, Operation and criteria. Stabilization).
  • Page 28: Adjustment Using Calibration Gas

    Parameter list. Connect the regulator to the test gas port using 3 mm or 1/8” inside Table 6-2 - Bump Testing diameter tubing. Table 6-2 - Bump Testing 22 • MRLDS-250 Infrared Gas Detector I&O Manual 026-1315 Rev 4...
  • Page 29 Adjustment Using Calibration Step Gas Cylinders If no further changes to the other parameters are required, press and hold the button for 5 seconds to exit the Parameter list. Upon exiting the parameters list, the gas detector will enter offline mode for a period of 10 minutes.
  • Page 30: Modbus Communications

    (regardless of the address  selected) to enable the master device to broadcast  simultaneously to all the detectors. The MRLDS-250 gas detector can be configured to communicate on an RS-485 network using  Refer to the specifications section for information on MODBUS-RTU protocol.
  • Page 31: Analog Output Registers

    7.4. Analog Output Registers Analog output registers are readable (using function code 03) and writable (using function code 06). Description Range Units P.-## 2000 Alarm setpoint 75-3500 P.-02 2001 Alarm ON delay 0-15 P.-04 (Alarm flag register 3000 is set to 1) 2002 Buzzer mute time 0-59...
  • Page 32: Input Status Flags

    Description Range P.-## 4000 Buzzer flag (0 or 1=ON) 0=Off 1=On 4001 Test required (If operating for >1 0=Okay year). (1=requires testing) 1=Test Table 7-4 - Output Status Flags 26 • MRLDS-250 Infrared Gas Detector I&O Manual 026-1315 Rev 4...
  • Page 33: Troubleshooting

    Gas Detector rate of Temperature change 0x00 The MRLDS-250 features sophisticated internal Rate of exceeds status monitoring and will indicate whether a fault Change ~1°C/min for condition exists on the front display (F.-XX, with XX...
  • Page 34: Diagnostic Attributes (P.-18)

    9999. Critical If not, Faults contact Table 8-2 - Diagnostics Attributes Emerson technical support for additional guidance. Table 8-1 - Fault Codes 28 • MRLDS-250 Infrared Gas Detector I&O Manual 026-1315 Rev 4...
  • Page 35: Resetting The Mrlds-250 To Default Values

    P.-18. The gas detector may now be  re-programmed for further troubleshooting if needed. Reserved Table 8-3 - Resetting MRLDS-250 to Default Values 8.4. Other Symptoms Table 8-2 - Diagnostics Attributes Other common wiring problems can also cause the gas detector to malfunction.
  • Page 36: Replacement Parts And Accessories

    Guard is used. The installer is responsible for determining whether the response time is suitable for the application. 026-1315 Installation and Operation Manual Table 9-1 - Replacement Parts and Accessories 30 • MRLDS-250 Infrared Gas Detector I&O Manual 026-1315 Rev 4...
  • Page 40 Emerson Climate Technologies Retail Solutions, Inc. and/or its affiliates (collectively “Emerson”), reserves the right to modify the designs or specifications of such products at any time without notice. Emerson does not assume responsibility for the selection, use or maintenance of any product. Responsibility for proper selection, use and maintenance of any product remains solely with the purchaser and end-user.

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