Lumel N31U Service Manual
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Lumel N31U Service Manual

Digital panel meter
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N31U
Service manual
1
DIGITAL PANEL METER
N31U
SERVICE MANUAL

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Summary of Contents for Lumel N31U

  • Page 1 N31U Service manual DIGITAL PANEL METER N31U SERVICE MANUAL...

  • Page 2: Table Of Contents

    N31U Service manual Contents 1 Application............................3 2 Meter set............................4 3 Basic requirements, operational safety....................5 4 Installation............................5 4.1 Installation method........................5 4.2 External connection diagram....................6 4.3 Examples of connecting the external transducers..............9 5 Service.............................9 5.1 Description of the frontal plate....................9 5.2 Buttons' functions........................11 5.3 Programming meter parameters.....................12...

  • Page 3: Application

    Service manual 1 Application The N31U meter is a digital panel meter adapted to be fixed to the panel designed to measure standard analog signals used in automation. N31U meters enable the measurement of standardized voltage and current signals, the signals from RTD and thermocouple sensors.

  • Page 4: Meter Set

    • The casing is made of a self-extinguishing plastics. • Wide range of supply voltages. The view of the N31U meter is shown in Fig. 1. Fig. 1: View of the N31U meter. 2 Meter set The meter set includes: •...

  • Page 5: Basic Requirements, Operational Safety

    4 Installation 4.1 Installation method +0.6 The N31U meters are designed to be mounted in a panel. Prior to installation a 92 +0.6 mm slot must be made in the panel. The maximum thickness of the panel material cannot exceed 6 mm. The meter should be mounted from the front of the panel with disconnected meter connection strips.

  • Page 6: External Connection Diagram

    The circuits of successive groups of the terminals are separated from each other, as shown in Fig. 4. Supply Measuring inputs, output 10/24 V d.c. Fig. 4: Galvanic isolation of the N31U meter.
  • Page 7 N31U Service manual Note: Unused terminals of the terminal strips must not be connected to any signals. Fig. 5: Signals on the terminal strips. Detailed description of the signals is shown in the table below, and the connection of the measuring signals is shown in Fig.
  • Page 8 N31U Service manual 14, 15 Alarm Alarm output, which is NO relay contact. 16, 17, 18 Power supply Meter power supply connection. Depending on the power supply voltage range, use connectors 17-18 or 16-17. Note: Connecting the power supply to connectors 16-18 will damage the meter! The connection of the basic measured signals is shown below.

  • Page 9: Examples Of Connecting The External Transducers

    Connections of the head-mount transducers when the transducers are supplied directly from the N31U meter are shown below. In the case of the transducers with a voltage output, the maximum current carrying capacity of the auxiliary supply output is 30 mA and the auxiliary supply source is only active for selected input ranges of 10V, 20MA and Pot10V.
  • Page 10 N31U Service manual Fig. 6: Front panel of the meter. Designation Description The upper (main) line of the display has 6 characters used to display a measuring value or a parameter value during the meter configuration. The lower (auxiliary) line of the display has 5 characters used to display a measuring value, not converted by the individual characteristic or, according to configuration, a unit or current time.

  • Page 11: Buttons' Functions

    N31U Service manual ºC m/min ºF l/min kvar szt/h Mvar km/h kg/h varh 5.2 Buttons' functions Cancel button: • Exiting the menu and exit to the main screen. • Exiting a lower level of the menu and return to a higher level.

  • Page 12: Programming Meter Parameters

    N31U Service manual Confirm button: • Entering the programming mode (holding down the button for at least 3 seconds). • Navigating the menu - entering the parameter value editing mode or entering the selected lower level of the menu. •...
  • Page 13 N31U Service manual While navigating the meter main menu with the groups of the parameters, the upper line of the display shows the name of the group and the lower line continuously displays the word MENU. After entering the group of the parameters (after pressing the confirm button), the upper line displays the value of a given setting and the lower line shows the name of the parameter which value is displayed in the upper line.

  • Page 14: How To Change Quantity Of A Selected Parameter

    N31U Service manual Minimum value on The unit which can Maximum value on Resolution - position Selection of main the display. For the display. For of the decimal point. be displayed in the displayed value. values lower than lower line (when...

  • Page 15: Programmable Meter Parameters, Default Parameters

    5.3.2 Programmable meter parameters, default parameters The N31U meters have a number of programmable parameters, which enable the meter to be adapted to the requirements of application. The parameters grouped according to the menu are shown in the tables below.
  • Page 16 N31U Service manual Default: NONE Mathematical function selection which should NONE – no additional mathematical operations. be applied for the measuring value. The Sqr – measuring value is squared. mathematical function is applied before the Sqrt – square root of the measuring value.
  • Page 17 N31U Service manual Default: 0000.00 000000 00000.0 Resolution, display format as the position of 0000.00 the decimal point. 000.000 00.0000 0.00000 AUTO – automatic position of the decimal point for maximum possible resolution. Value selection which should be displayed in Default: "-----"...
  • Page 18 N31U Service manual Table 5 Parameter Description Range of changes symbol Default: 1 MODBUS network meter address 1...247 Default: F8N1 The transmission frame type of RS-485 F8N1 interface. Setting the parity bits and the F8N2 number of stop bits. F8O1 F8E1 Default: 9.6k...

  • Page 19: Meter Functions

    5.4.1 Measurement The N31U meters continuously measure the selected quantity, which is averaged in a given period, and convert it according to the selected mathematical function, and then convert it based on the individual characteristic. When shortening the measurement time, it needs to be considered that the shorter the measurement time, the greater the influence of noise on the measuring value, and therefore the lower the stability of indications.

  • Page 20: Averaging The Measuring Quantity

    5.4.1.2 Minimum and maximum measuring values The N31U meter continuously measures the signal on the indicated input. The measuring value (displayed) is constantly monitored, if the measuring range is not exceeded during the measurement. If the value is smaller than the current minimal value, then the new minimal value is saved.

  • Page 21: Mathematical Functions

    N31U Service manual 5.4.1.3 Mathematical functions The N31U meters have a functionality that enables the conversion of the measuring value by the selected mathematical function (MAtH setting): • Sqr – measured value is squared. • Sqrt – square root of the measured value.
  • Page 22 N31U Service manual Fig. 11: Example of the individual characteristic. The approximating functions strongly differ from the linear function, so it is important to keep in mind that the higher the number of the introduced points, the smaller the linearization error of the function.

  • Page 23: Alarm Output

    Service manual 5.4.2 Alarm output N31U meters are equipped with one alarm output as standard. The alarm output element is an electromagnetic transmitter. Alarm output is independently configured and can be configured to work in one of six modes. It is possible to select the value controlling the alarm (see Fig. 9), define the alarm state change thresholds and define delays alarm activation and deactivation for each of the alarms.

  • Page 24: Rs-485 Interface

    The terminals A, B and GNDI terminals which location is shown in Fig. 5 allow to connect the RS-485 interface to the N31U meter. It is required to connect the lines A and B in parallel with their equivalents in other devices to obtain the correct transmission.

  • Page 25: Description Of The Modbus Protocol Implementation

    Operation mode: RTU frame format 8n1, 8n2, 8o1, 8e1. • Maximum response time: 50 ms. 5.5.3 Implemented functions of MODBUS protocol The following functions of the MODBUS protocol have been implemented in the N31U meters: • 03 (03h) – readout of registers group. •...

  • Page 26: Map Of The Registers

    B1 B0 B3 B2. The table below shows the register map of the N31U meter. The addresses in the table are the physical addresses. The register number should be increased by 1 when using the programs where the addresses are provided in a logical format.
  • Page 27 N31U Service manual 10 V – voltage measurement 0...20 mA – current measurement 4...20 mA – current measurement Averaging - number of the samples averaged for one measurement. 4001 1...600 Sampling rate 100 ms (200 ms for the RTD sensors in 3-wire system).
  • Page 28 N31U Service manual 4009 0...9999 Access protection code to make changed in the configuration using the meter menu. It would be required to provide a code each time when entering the meter menu in case of entering a value higher than zero.

  • Page 29: Registers 4200 - 4219

    Device ID 4201 Software version - version number multiplied by the value 100. 4202 N31U meter type - code corresponding to the "U" character. 4203 Meter serial number - older 16 bits. 4204 Meter serial number - younger 16 bits.

  • Page 30: Registers 7500 - 7530 And 7000 - 7030

    N31U Service manual Alarms - alarm event memory 4209 Alarm 1: Value 1 - active mode to register the alarm event. Value zero - no alarm events registered. 4210 reserved Status bits - value 1 indicates the occurrence of a given event 4211 Corrupted configuration registers from register group 4000.

  • Page 31: Registers 7600 - 7668 And 7200 - 7336

    N31U Service manual 5.5.4.4 Registers 7600 – 7668 and 7200 – 7336 The 32-bit and the corresponding 16-bit registers with the configuration parameters. The address for 32-bit variables was entered in the address field, while the address for accessing data stored in two successive 16-bit registers was entered in a bracket.
  • Page 32 N31U Service manual 7626 7252 -99999...999999 7627 7254 -99999...999999 7628 7256 -99999...999999 7629 7258 -99999...999999 7630 7260 -99999...999999 7631 7262 -99999...999999 7632 7264 -99999...999999 7633 7266 -99999...999999 7634 7268 -99999...999999 7635 7270 -99999...999999 7636 7272 -99999...999999 7637 7274 -99999...999999 7638 7276 -99999...999999...

  • Page 33: Error Codes

    Service manual 6 Error codes The N31U meters have several diagnostic functions and settings built-in that allow to limit the displaying. So the display may show and the status registers may store information about the diagnosed error, event or fault. Possible messages and their potential causes are listed below.

  • Page 34: Technical Data

    N31U Service manual 7 Technical data Measuring ranges Indication range Input type Class (rated range) PT100 -200...850 ºC (-200...850 ºC) PT1000 -200...850 ºC (-200...850 ºC) 400 Ω 0...440 Ω (0...400 Ω) 4000 Ω 0...4040 Ω (0...4000 Ω) Thermocouple type E -205...1000 ºC (-200...1000 ºC)
  • Page 35 N31U Service manual Additional measurement errors Automatic compensation of reference junction temperature < 1 ºC Automatic compensation of wire resistance for RTD sensors < 0.5 ºC Automatic compensation for resistance measurements < 0.2 Ω (range 400 Ω) < 2 Ω (range 4000 Ω)

  • Page 36: Ordering Code

    300 V for the circuits: supply, alarm, voltage: measurement, auxiliary supply, 50 V for the circuits: RS-485 interface Altitude a.s.l. < 2000 m 8 Ordering code Panel meter N31U XXXX Acceptance tests: without calibration certificate with calibration certificate Version: standard...
  • Page 37 N31U Service manual LUMEL S.A. ul. Słubicka 4, 65-127 Zielona Góra, POLAND tel. 68 45 75 100 www.lumel.com.pl Technical support: tel.: (+48 68) 45 75 143, 45 75 141, 45 75 144, 45 75 140 e-mail: export@lumel.com.pl Export department: tel.: (+48 68) 45 75 130, 45 75 131, 45 75 132 e-mail: export@lumel.com.pl...

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