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OM2-5190-0920

Field-Based Analog

4 - 20mA DC Current Meter

Model NWA300

User's Manual

Summary of Contents for NWA300

Page 1: ...OM2 5190 0920 Field Based Analog 4 20mA DC Current Meter Model NWA300 User s Manual ...

Page 2: ...ss for a particular purpose and makes no express warranty except as may be stated in its written agreement with and for its customer In no event shall Azbil Corporation be liable to anyone for any indirect special or consequential damages This information and specifications in this document are subject to change without notice 1994 2020 Azbil Corporation All Rights Reserved ...

Page 3: ... 3 1 3 Structure and Function 5 Structure 5 Main Unit Indicator 8 Terminal Box 9 Chapter 2 Installation 11 2 1 Before Installation 11 Mounting Environment 11 2 2 Installation 12 Mounting 12 2 3 Wiring 14 Wiring when only one NWA is used 16 Wiring when multiple NWAs are used 18 Wiring for the pressure resistant explosion proof model 19 Chapter 3 NWA Operation 20 3 1 Start up 20 ...

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Page 5: ...e appendix Indication Of NWA Standard Specifications And Tag No Pay special attention to the following two items Structure of the main unit Scale type Inquiries If you find errors in the specification or have any questions regarding the specifications please contact the azbil Group sales office In this case be sure to inform us of the NWA Tag and Product Numbers Notes on Storage When storing the N...

Page 6: ...the names and functions of each section Notes regarding use of the explosion proof NWA 1 1 System Configuration Overview The NWA analog meter displays analog DC signals in the 4 to 20 mA range obtained from various field instruments Current Indication Using the NWA The following shows the configuration of a typical current indication system using the NWA Fig 1 1 Configuration of the NWA Current In...

Page 7: ... proof structure is totally sealed which contains possible internal explosions and prevents ignition of external explosive gases Selection of Mounting Location When selecting a mounting location for the NWA observe the following conditions Dangerous locations in which the NWA can be safely installed are defined as follows Gases classed as requiring explosion proof instruments Atmospheres with a fl...

Page 8: ...istant explosion proof structure are maintained by the length of the flamepath gap and by the mechanical strength of the casing Therefore make sure that there is no corrosion distortion or scarring of the case cover any of which may cause reduced mechanical strength Handle the meter carefully to avoid damage to screws and joints If any of the above conditions is not satisfied the NWA s explosion p...

Page 9: ...5 1 3 Structure and Function Structure Major components The NWA analog meter consists of the main unit indicator and the terminal box as shown below Fig 1 3 General View of the NWA ...

Page 10: ... Model No and Product No are inscribed and the explosion proofing certification seal is stamped Pressure resistant packing cable adapter Seals the cable terminals to maintain explosion proofing and improve insulation properties and mechanical strength This adapter is required for explosion proof instrumentation See Fig 1 4 and Fig 1 5 External grounding terminal Connect the ground lead from this t...

Page 11: ...7 Fig 1 4 General View of the Pressure Resistant Packing Cable Adapter Fig 1 5 Assemblies of the Pressure Resistant Packing Cable Adapter ...

Page 12: ...al from the transmitter and indicates values Name of each Section The following shows the name of each section of the main unit indicator Fig 1 6 Main Unit Indicator Detail Function of each section The following table shows the function of each section of the main unit indicator Name Function Indicator Incorporates 240 meter ...

Page 13: ...9 Terminal Box Description The terminal box is provided with output signal terminals Name of section The following shows the name of each section of the terminal box Fig 1 7 Terminal Box Detail ...

Page 14: ...hey are used as relay terminals when multiple NWA meters are connected See the subsection Electrical Installation 4 on page 19 Internal grounding terminal If the NWA meter is not immune to electrical noise connect one end of the shield wire to this terminal Not normally used This terminal is internally connected to the external grounding terminal When this terminal is used make sure that two point...

Page 15: ...onmental conditions Install the meter in a location with ambient temperatures within 10 to 60 C and ambient humidity within 5 to 100 RH and which is not subject to rapid temperature or humidity changes Avoid installing the meter near large current cables motors or transformers that might cause electromagnetic interference Avoid installing the meter in locations subject to excessive vibration or sh...

Page 16: ...les at the back of the main unit See Fig 2 1 2 Using the mounted bracket secure the main unit to the 2B pipe vertically or horizontally with a U bolt See Fig 2 2 Notes Make sure that the 2B pipe is fixed securely Figure Fig 2 1 shows the bracket mounting holes Fig 2 2 shows the NWA meter mounted on a 2B pipe Fig 2 1 Rear of the NWA ...

Page 17: ...13 Fig 2 2 NWA Analog Meter Mounted on 2 Pipe ...

Page 18: ...e NWA Cable connection position Cable selection and installation Wiring procedure Caution Avoid connecting the NWA to commercial power Otherwise the internal measurement circuit may be irrevocably damaged Connection position The following shows the terminal block of the terminal box Fig 2 3 Terminal Block ...

Page 19: ... φ11 For termination a crimp contact M4 screw with insulated sleeve is recommended Cable installation When installing the cable between the NWA and the transmitter keep the following points in mind Avoid installing the cable near electrical noise emitting equipment such as large current transformers motors or power supplies Do not lay the cables in trays or ducts with other power cables To protect...

Page 20: ... used When the transmitter is provided with an output signal terminal for external meters Case 1 Notes Don t remove a jumper board on the terminal board M and M Case 2 Notes Don t remove a jumper board on the terminal board M and M ...

Page 21: ...17 When the transmitter is not provided with an output signal terminal for external meters Notes Don t remove a jumper board on the terminal board M and M ...

Page 22: ...loop voltage and internal impedance of each device into account When the transmitter is provided with an output signal terminal for external meter Notes Don t remove a jumper board on the terminal board M and M When the transmitter is not provided with an output signal terminal for external meters Notes Don t remove a jumper board on the terminal board M and M ...

Page 23: ...hen lock it using a 3 mm hexagonal wrench Lock both the main unit cover and the terminal cover at the same time See Fig 2 4 As products from Azbil Corporation employ a pressure resistant packing system pressure resistant packing is required for cable installation in areas requiring explosion and pressure resistance Use Azbil Corporation s standard pressure resistant packing adapter For details of ...

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Page 25: ...chapter when activating the NWA for the first time 3 1 Start up Procedure Step Description 1 Make sure that wiring for the NWA is completed 2 Make sure that notes and cautions regarding use of the NWA have been fully observed 3 Turn on the power to the transmitter This completes start up of the NWA ...

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Page 28: ...to your use 3 Measures to be taken to secure the required level of the reliability and safety of your Equipment in your use Although azbil is constantly making efforts to improve the quality and reliability of Azbil Corporation s products there exists a possibility that parts and machinery may break down You are required to provide your Equipment with safety design such as fool proof design 1 and ...

Page 29: ...margin of your machine or equipment you are required to renew any Azbil Corporation s products every 5 to 10 years unless otherwise specified in specifications or instruction manuals System products field instruments sensors such as pressure flow level sensors regulating valves etc will reach the end of their life due to aged deterioration of parts For those parts that will reach the end of their ...

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Page 31: ...Document Number OM2 5190 0920 Document Name Field Based Analog 4 20mA DC Current Meter Model NWA300 User s Manual Date 1st edition Sep 1994 3rd edition Jan 2020 Issued Edited by ...

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