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Emerson Rosemount 848T Reference Manual

Wireless temperature transmitter
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Reference Manual
00809-0100-4848, Rev BB
September 2019
™
Rosemount
848T Wireless Temperature
Transmitter

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Summary of Contents for Emerson Rosemount 848T

  • Page 1 Reference Manual 00809-0100-4848, Rev BB September 2019 ™ Rosemount 848T Wireless Temperature Transmitter...
  • Page 2 The products described in this document are NOT designed for nuclear-qualified applications. Using non-nuclear qualified products in applications that require nuclear-qualified hardware or products may cause inaccurate readings. For information on Rosemount nuclear-qualified products, contact a Emerson Sales Representative. WARNING Explosions could result in death or serious injury.
  • Page 3 NOTICE The Rosemount 848T Wireless and all other wireless devices should be installed only after the Wireless Gateway has been installed and is functioning properly. Wireless devices should also be powered up in order of proximity from the Wireless Gateway, beginning with the closest.

  • Page 5: Table Of Contents

    5.2 Calibration............................41 5.3 Power module replacement......................42 5.4 Spare parts............................. 43 Chapter 6 Troubleshooting......................45 6.1 Safety messages..........................45 6.2 General information........................45 Chapter 7 Appendix A........................49 7.1 Product certifications........................49 7.2 Ordering, information, specifications, and dimensional drawings...........49 Emerson.com/Rosemount...
  • Page 6 Contents Reference Manual September 2019 00809-0100-4848 Emerson.com/Rosemount...

  • Page 7: Chapter 1 Introduction

    Sensor Connections • Physical Installation • 4-20 Milliamp Inputs Commissioning • Insert Power Module • Network Status • Verify Operation Operation and Maintenance • Calibration • Power Module Replacement Troubleshooting • General Information Specifications and Reference Data • Specification Emerson.com/Rosemount...

  • Page 8: Safety Messages

    • Product Certifications • Installation Drawings Rosemount 848T Wireless Temperature Transmitter Features of the Rosemount 848T Wireless include: • Up to four independently configurable RTD, thermocouple, ohm, millivolt, and 4–20 mA inputs • Eight user-configurable alerts for process and device variables •...

  • Page 9: Considerations

    30 °C. Considerations 1.3.1 General Electrical temperature sensors such as RTDs and thermocouples produce low-level signals proportional to their sensed temperature. The Rosemount 848T converts this signal into a ® robust WirelessHART digital signal. 1.3.2 Commissioning The transmitter can be commissioned before or after installation.

  • Page 10: Return Of Materials

    Return of materials To expedite the return process in North America, call the Emerson National Response Center toll-free at 800 654 7768. This center, available 24 hours a day, will assist you with any needed information or materials.

  • Page 11: Product Recycling/Disposal

    Reference Manual Introduction 00809-0100-4848 September 2019 For other locations outside North America, contact an Emerson Process Management sales representative for further instructions. Note If the device has been exposed to a hazardous substance, a Material Safety Data Sheet (MSDS) must be included with the returned materials. An MSDS is required by law to be available to people exposed to specific hazardous substances.
  • Page 12 Introduction Reference Manual September 2019 00809-0100-4848 Emerson.com/Rosemount...

  • Page 13: Chapter 2 Configuration

    Process leaks could result in death or serious injury. Do not remove the thermowell while in operation. Install and tighten thermowells and sensors before applying pressure. Electrical shock could cause death or serious injury. Use extreme caution when making contact with the leads and terminals. Emerson.com/Rosemount...

  • Page 14: Bench Top Configuration

    AMS Wireless Configurator ® AMS Wireless Configurator is capable of connecting to devices directly, using a HART modem, or wirelessly using the Emerson Smart Wireless Gateway. When configuring the device, double click the device icon or right click and select Configure. 2.3.1...

  • Page 15: Default Settings

    This option code is not required to configure the self-organizing network parameters, or to set all of the sensors identically. Device network configuration 2.5.1 Join device to network Fast Keys 1, 12 Emerson.com/Rosemount...

  • Page 16: Configure Update Rate

    The default setting for update rate is one minute. This may be changed at commissioning, or at any time using AMS Wireless Configurator. The update rate is user selectable, and can be configured between four seconds and 60 minutes. Procedure 1. From the Home screen, select 2: Configure. Emerson.com/Rosemount...

  • Page 17: Sensor Configuration

    Configure engineering units Fast Keys 2, 1, 3, 3 Each input can be configured on the Rosemount 848T for different engineering units. The supported units are °C, °F, °R, °K, millivolts, ohms, and milliamps. Procedure 1. From the Home screen, select 2: Configure.

  • Page 18: Advanced Configuration (Optional)

    41 °F (5 °C). Dead band is a buffer so the alerts do not toggle on and off when the temperature measurement is close to the trigger point. High alert configuration Low alert configuration Trigger point 212 °F (100 °C) 32 °F (0 °C) Dead band 41 °F (5 °C) 41 °F (5 °C) Emerson.com/Rosemount...

  • Page 19: Device Temperature Engineering Units

    4. Select 3: Unit. 2.7.3 Write protect Fast Keys 2, 2, 7, 1 The Rosemount 848T has a software write protect security feature. To view write protect security settings: Procedure 1. From the Home screen, select 2: Configure. 2. Select 2: Manual Setup.
  • Page 20 4. Select 2: AC Power Filter. 2.7.5 Device tag Fast Keys 2, 2, 9, 1 The Rosemount 848T HART device tag (eight characters) can be configured to identify the device. Procedure 1. From the Home screen, select 2: Configure. 2. Select 2: Manual Setup.

  • Page 21: Fast Key Sequences

    8. RTD 2-wire offset 1. Process Sensors 5. Simulate 2. Electronics Temperature 3. Supply Voltage 1. Perform Master Reset 2. Measurement History 3. Advertise to New Devices 2.7.7 Fast Key sequences Table 2-1 lists the Fast Key sequences for common transmitter functions. Emerson.com/Rosemount...
  • Page 22 Configuration Reference Manual September 2019 00809-0100-4848 Note The Fast Key sequences assume that Device v3, DD v1 is being used. Table 2-1: Rosemount 848T Wireless Fast Key Sequence Function Menu items sequence Device Information 1, 13 Tag, Long Tag, Descriptor, Message, Date, SI Unit Restriction,...

  • Page 23: Chapter 3 Installation

    Gateway, beginning with the closest. This will result in a simpler and faster network installation. Enable Active Advertising on the Gateway to ensure that new devices join the network faster. For more information, see the Emerson Wireless 1420 Gateway. Emerson.com/Rosemount...
  • Page 24 The temporary orange plugs should be replaced with the included conduit plugs using approved thread sealant. Figure 3-2: Conduit Plug Field Communicator connections The Power Module needs to be connected for the Field Communicator to interface with ™ the Rosemount 848T Wireless. Emerson.com/Rosemount...

  • Page 25: Sensor Connections

    September 2019 Figure 3-3: Field Communicator Connection Diagram Sensor connections The Rosemount 848T is compatible with a number of RTD and thermocouple sensor types. Figure 3-4 shows the correct input connections to the sensor terminals on the transmitter. To ensure a proper sensor connection, anchor the sensor lead wires into the appropriate compression terminals and tighten the screws.
  • Page 26 1 and 2 or 3 and 4. To install voltage adapter: Procedure 1. Open terminal screws 2 and 3 on BOTH inputs. Note The screws are captive and should NOT be completely removed by using excess force. Emerson.com/Rosemount...
  • Page 27 4. Tighten all terminal screws to lock divider in place. 3.3.2 Wiring 0-10 volt inputs on the voltage adapter Wiring voltage 0-10 volt inputs using the adapter follows the same procedure as mV inputs and thermocouples. Figure 3-5 below shows how to connect the voltage leads. Emerson.com/Rosemount...
  • Page 28 If neither of these is practical, a sensor trim may be performed to compensate, assuming the source resistance is constant over the voltage range of interest the procedure for performing a Sensor trim. Emerson.com/Rosemount...
  • Page 29 3.3.4 Pt100 4-wire RTD No lead wire resistance effect 3.3.5 Pt100 3-wire RTD Lead wire imbalance seen by the transmitter = 0.5 Ω Basic Error = = 1.3 °C Error due to amb. temp. var. of ±25 °C = Emerson.com/Rosemount...
  • Page 30 5 ohm resistor to create a 20–100 mV signal. It is optimal to use a 5 ohm resistor with stable operation over the ambient temperature range where the 848T is located. See Figure 3-6 below for information on wiring. Emerson.com/Rosemount...
  • Page 31 Analog region Sensor Saturation > 21.71 > 108.55 Upper Alarm Sensor Out of Limits 20.8–21.71 104–108.55 Upper Saturation Good 3.9–20.8 19.5–104 Normal Region Sensor Out of Limits 3.79–3.9 18.95–19.5 Lower Saturation Sensor Saturation < 3.79 < 18.95 Lower Alarm Emerson.com/Rosemount...

  • Page 32: Physical Installation

    If using the mounting bracket (Option Code B6), mount to a 2-in. pipe. 3. Run wiring (and conduit, if necessary) from the sensor to the Rosemount 848T. For an easier installation, use the outside conduit entries, as shown below. Any unused conduit entries should be sealed with an approved sealant using the included threaded conduit plug.
  • Page 33 00809-0100-4848 September 2019 Conduit entries Conduit plug 4. Pull the wiring through the threaded conduit entry of the Rosemount 848T. 5. Attach the sensor wiring to the terminals as indicated in Figure 3-4. Note that Terminal Screw 5 is for attaching the shield wire of the sensor to the device. See Grounding practices for more information.

  • Page 34: Grounding Practices

    2. Ensure the sensor wiring is electrically isolated from the transmitter housing. Shield ground point Grounded thermocouple option Procedure 1. Ground the sensor wiring shield at the sensor. 2. Ensure the sensor wiring and shield is electrically isolated from the transmitter housing and terminal screw 5. Emerson.com/Rosemount...
  • Page 35 1. Ground the 4–20 mA signal at the power supply, making sure not to attach the signal shield to terminal screw 5. 2. The 4–20 mA signal shield should be electrically isolated from the Rosemount 848T Wireless housing and the 4–20 mA device to ensure a single point ground.
  • Page 36 Installation Reference Manual September 2019 00809-0100-4848 Emerson.com/Rosemount...

  • Page 37: Chapter 4 Commissioning

    Wireless devices should also be powered up in order of proximity from the Wireless Gateway, beginning with the closest. This will result in a simpler and faster network installation. For more information see Emerson Wireless 1420 Gateway. Insert power module At commissioning, the power module needs to be inserted.

  • Page 38: Network Status

    For HART communication, an 848T Wireless DD is required. For connecting with a Field Communicator, refer to Figure 3-3. Function Key Sequence Menu Items Communications 3, 3 Join Status, Communications Status, Join Mode, Number of Advertisements Heard, Number of Available Neighbors, Number of Join Attempt Emerson.com/Rosemount...
  • Page 39 Figure 4-2: Wireless Gateway Explorer Page Note If the device joins the network and immediately has an alarm present, it is likely due to sensor configuration. Check the sensor wiring (see Rosemount 848T Terminal Diagram Figure 4-2) and the sensor configuration (see 848T...
  • Page 40 Commissioning Reference Manual September 2019 00809-0100-4848 Emerson.com/Rosemount...

  • Page 41: Operation And Maintenance

    The sensor trim function calibrates the sensor to the transmitter in temperature units or raw units. Unless the site-standard input source is NIST-traceable, the trim functions will not maintain the NIST-traceability of the system. Emerson.com/Rosemount...

  • Page 42: Power Module Replacement

    The power module with the wireless unit contains two “C” size primary lithium/thionyl chloride batteries. Each battery contains approximately two-and-a-half grams of lithium, Reference conditions are 70 °F (21 °C), transmit rate of once per minute, and routing data for three additional network devices. Emerson.com/Rosemount...

  • Page 43: Spare Parts

    Kit, Spare cable gland, ½-NPT, 7.5mm - 11.9mm (qty 1) 00648-9010-0001 Kit, Spare cable gland, ½-NPT, thin wire, 3mm - 8mm (qty 1) 00648-9010-0003 Mounting bracket for 2-in. pipe mount - SST bracket and bolts 00848-4350-2001 M20 cable gland adapter (qty 4) 00849-1605-0001 Emerson.com/Rosemount...
  • Page 44 Operation and Maintenance Reference Manual September 2019 00809-0100-4848 Emerson.com/Rosemount...

  • Page 45: Chapter 6 Troubleshooting

    Recommended actions Electronics An electronics error has occurred that 1. Reset the device. Failure could impact the device measurement 2. Reconfirm all of the configuration reading. items in the device. 3. Contact a service center if the condition persists. Emerson.com/Rosemount...
  • Page 46 The electronics temperature is outside of 1. Make sure the device is installed in Temperature the operating range of the transmitter. an environment within the device Out of Limits operating temperature range. 2. Contact a service center if the condition persists. Emerson.com/Rosemount...
  • Page 47 Verify the device is not installed in extreme temperatures Verify that the device is not a network pinch point Check for excessive network rejoins from poor connectivity Limited Bandwidth Error Reduce the Update Rate on the transmitter Increase communication paths by adding more wireless points Emerson.com/Rosemount...
  • Page 48 Troubleshooting Reference Manual September 2019 00809-0100-4848 Emerson.com/Rosemount...

  • Page 49: Chapter 7

    3. Click Manuals & Guides. 4. Select the appropriate Quick Start Guide. Ordering, information, specifications, and dimensional drawings To view current Rosemount 848T Wireless ordering information, specifications, and dimensional drawings, follow these steps: Procedure 1. Go to Emerson.com/Rosemount/848T Wireless Temperature Transmitter.
  • Page 50 Emerson Terms and Conditions of Sale are available upon request. The Emerson logo is a Facebook.com/Rosemount trademark and service mark of Emerson Electric Co. Rosemount is a mark of one of the Youtube.com/user/RosemountMeasurement Emerson family of companies. All other marks are the property of their respective owners.

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