Lumel N20 User manual

1
DIGITAL PANEL METER
N20
USER’S MANUAL

2

3
Contents
1. APPLICATION AND METER DESIGN ........................................ 5
2. METER SET................................................................................. 6
3. BASIC REQUIREMENTS, OPERATIONAL SAFETY ................. 6
4. INSTALLATION ........................................................................... 7
5. SERVICE...................................................................................... 9
6. ERROR CODES ........................................................................ 18
7. TECHNICAL DATA .................................................................... 19
8. EXECUTION CODES ................................................................ 22
9. MAINTENANCE AND GUARANTEE ........................................ 26

4

5
1. APPLICATION AND METER DESIGN
The N20 meter is a digital programmable panel instrument destined
for measurements of d.c. voltages or d.c. currents: unipolar or bipolar,
temperature through thermocouples (J, K) and Pt100 resistance
thermometers.
The readout eld is a LED display which enables the exposition of results
in red, green or orange colours. The eCon software is destined for the
conguration of the N20 meter. The N20 meter must be connected to the
PC computer through a PD14 programmer.
Following parameters can be reprogrammed:
– display colour, individually in three intervals,
– thresholds of displayed overows
– display precision of the result (decimal point),
– highlight of the unit,
– automatic or manual compensation: temperature of ends in
measurements with thermocouples, or wire resistance in Pt100
measurements,
– averaging time of the measurement,
– recalculation of indications (individual characteristic),
– two alarms of OC type operating in six working modes.
The alarm output switching on is signaled by the highlight of the triangular
alarm index situated at the left display side, for the suitable alarm digit.
The highlight colour is always different from the colour of the displayed
(measured) value. The meter has a galvanic separation between the
supply, measuring inputs and the programmer input.
The protection level from the frontal side is IP65.
Meter overall dimensions: 96 ´ 48 ´ 64 mm (including terminals).
Fig. 1. view of the N20 meter

6
2. METER SET
The set is composed of:
- N20 meter.................................................. 1 pc
- user’s manual............................................ 1 pc
- guarantee card .......................................... 1 pc
- clamps to x in the panel......................... 4 pcs
- seal............................................................ 1 pc
- set of labels with units ............................... 1 pc
When unpacking the meter, please check whether the type and execution
code on the data plate correspond to the order.
3. BASIC REQUIREMENTS
AND OPERATIONAL SAFETY
In the safety service scope, the N20 meter meets the
requirements of the EN 61010-1 standard.
Observations concerning the operational safety:
▪ All operations concerning transport, installation, and commissioning
as well as maintenance, must be carried out by qualied, skilled
personnel, and national regulations for the prevention of accidents
must be observed.
▪ Before switching the meter on, one must check the correctness of
connection to the network.
▪ The programming of meter parameters must be carried out when
measuring circuits are switched off.
▪ Before removing the meter housing, one must switch the supply off
and disconnect measuring circuits.
▪ The removal of the meter housing during the guarantee contract
period may cause its cancellation.
▪ The meter is destined to be installed and used in industrial
electromagnetic environment conditions.

7
4. INSTALLATION
The meter has separable strips with screw terminals which enable the
connection of external wires of 2.5 mm2. One must prepare a hole of
92+0.6 ´ 45+0.6 mm in the panel which the thickness should not exceed 6
mm. The meter must be introduced from the panel front with disconnected
supply voltage. Before the insertion into the panel, one must check the
correct placement of the seal. After the meter insertion into the hole, x
the meter by means of the clamps (g. 2.).
▪ One must remember that in the building installation, a switch or a
circuit-breaker should be installed. This switch should be located
near the device, easy accessible by the operator, and suitably
marked.
Fig. 2. Meter xing.
Fig. 3. Meter overall dimensions

8
4.1. Connection Diagrams
Resistance thermometer RTD
in a two-wire system with manual
compensation
Resistance thermometer RTD
in a three-wire system with automatic
compensation
Thermocouple J, K Current input
Voltage input
The supply must be connected by a two-wire cable, of a suitable wire
diameter, ensuring its protection by means of an installation cut-out.
Fig. 4. Electrical connections of the N20 meter
Fig. 5. Connections of measurement inputs

9
5. SERVICE
5.1. Display Description
5.2. Messages after the Supply Connection
After connecting the supply, the meter displays the N20 - L meter name
– where L is the letter marking the execution: U– voltage measurement,
I– current measurement, r– measurement of Pt100 temperature,
t – measurement of the temperature by thermocouples, s– custom-made
execution. Next, the program version is displayed in the shape r x.xx
– where x.xx is the number of the actual program version or the number
of the custom-made execution.
Till the time to obtain the required number of correct measurements (acc.
to the table 1), the actual value from the measurement 1 is displayed,
signaled by the highlighted index of the actual value.
In case of an error occurrence or an overow of the range value, a mes-
sage described in the section 6 will be displayed on the display.
Overows of the measuring range are additionally signaled by the actual
value signal index.
Alarm
indexes
Highlighted
unit
Measured
value
Indexes of actual value
displaying
Fig. 6. Frontal panel

10
5.3. Meter Configuration by Means of the eCon
software
The eCon software is destined for the N20 meter conguration.
One must connect the PC computer through the PD14 programmer and
congure the connection choosing Communication -> Serial port from
the menu (for the N20 meter we choose the address 1, baud rate 9600
kb/s, the mode RTU 8N2, timeout 1000ms and the appropriate port COM
under which the controller of the PD14 programmer has been installed).
CAUTION! One must carry out the programming of meter parameters
when measuring circuits are switched off!
Fig.7. Conguration of the connection with the N20 meter

11
After choosing the group: - Display settings, following elements are
possible to be congured:
a) display colours of the measured value. Upper colour, middle co-
lour, Lower colour. The displayed range is divided into three zones
separated by KpL and KpH values (suitably the lower threshold KpL
and the upper threshold KpH of display colour change – g.9). The
colour of displayed numbers for each zone is selected from three
accessible colours: green, orange and red. KpL and KpH values are
set by the user and concern the displayed value (i.e. taking also into
consideration the individual characteristic). The manufacturer value
KpL is equal 100% of the rated value, however KpH is equal 105% of
the rated value, e.g. for a 10 V meter execution they are respectively:
for KpL – 10 V and for KpH – 10.5 V.
Caution! After setting the individual characteristic, KpL and KpH
values are not automatically updated.
After the connection conguration, one must choose Select device à
à Meters à N20 (Fig.8) from the menu, conrm with Congure and
next click the icon Download conguration to eCon
in order to read out all parameters. To change parameters, enter the new
value in the parameter window and click the Save button.
Fig.8. Device selection in eCon software.

12
5.3.1. Setting of Display Parameters
After choosing the group: - Measurement settings, following elements
are possible to be congured:
a) Compensation of terminal temperatures (in the version with thermo-
couple measurement or resistance of wires for the version with Pt100
measurements). The switching of the automatic compensation off,
enables to give terminal temperature values or the wire resistance
used in calculations. As the resistance, one must give the sum of
both wires. At the beginning, the compensation is switched by the
manufacturer on.
Fig. 9. Window view of the display parameter conguration
b) decimal point – measurement precision. We have 5 possible display
congurations at choice.
When choosing, one must follow the measurement precision, e.g.:
for the 10 V range – the measurement error is 0.02 V, so the choice
of precision with three places after the decimal point does not give
more precise measurements. When manufacturing, for executions
with voltage and current measurements, the precision 000.00 is set;
for executions with Pt100 temperature measurement – 0000.0; for
execution with the temperature measurement through thermocouples
– 00000.
c) unit highlight. The unit highlight can be enabled or disabled. When
manufacturing it is enabled.

13
Table 1
0.5 s 2 every 0.5 s
1 s 7 every 0.5 s
3 s 20 every 0.5 s
5 s 33 every 0.5 s
10 s 67 every 0.5 s
15 s 100 every 0.5 s
20 s 134 every 0.5 s
Averaging
time
Number of
averaging time Updating of displayed values
b) Averaging time: till the time to obtain the required number of correct
measurements (according to the table 1), the actual value from 1 mea-
surement is displayed. After measuring a denite number of measure-
ments, the arithmetic mean of measured measurements is displayed.
The measurement of a value beyond the measuring range causes the
display of overow and the start to count correct measurements from
the beginning. The time is set on 1 s by the manufacturer.
c) thresholds of displayed overows: one can narrow limits beyond
which overows will be displayed, taking into consideration the
individual characteristic.
When the measured value is beyond 0…110% of the rated value
(e.g. for the 10 V execution, it is the range -1…11 V) V), the
overow is displayed.
In manufacturing conditions, the range –19999…99999 is set.
d) switching the individual characteristic on. In manufacturing
conditions the characteristic is switched off. An example of
conguration is given below for e.g. operation of the N20 meter
when choosing the kilovolt unit (kV) – the result is divided by 1000.
After pressing the Save button, parameters aand bof the straight
line equation are written in the meter.

14
5.3.2. Setting of Alarm Parameters
After choosing the group: - Alarm 1 or Alarm 2, following elements are
possible to be congured:
a) alarm 1,
b) alarm 2,
Both alarms are working independently and each of them has 6 working
modes: n-on, n-off, on, off, hon and hoff, which are presented on the g. 10.
Alarm thresholds Aoff and Aon are set in values of the measured quantity
taking into consideration the individual characteristic. In manufacturing
conditions both alarms are set on the n-on mode. The exemplary
conguration of alarms 1 and 2 is presented on the g. 11.
Fig. 10 Window view of the measurement parameter
conguration.

15
a) n-on
b) n-off
c) on
d) off
Remaining types of the alarm: h-on – always switched on;
h-off – always switched off.
The delay time concerns both the alarm switching on and switching off.
Fig. 11. Alarm types: a) n-on, b) n-off, c) on, d) off

16
5.3.3. Measured Values and Statuses
After choosing the group: - measured values, following information is displayed:
- measured value (displayed);
- kind of input – execution;
- number of the person responsible for the calibration;
- serial number of the meter.
Fig. 12. View of the alarm 1 conguration window
Fig. 13. View of the alarm 2 conguration window
Fig. 14. View of the
Measured values and
Statuses conguration
window

17
5.4. Manufacturer Parameters
Table 2
Parameter description Range/value Manufacturer value
Display colour of the measured
upper value red, green, orange red
Display colour of the measured
middle value red, green, orange orange
Display colour of the measured
lower value red, green, orange green
Upper threshold - KpH -19999…99999 105% of rated value Un,
In or 200°C
Lower threshold - KpL -19999…99999 100% of rated value Un,
In, or 100°C
Decimal point 00000, 0000.0, 000.00,
00.000, 0.0000,
000.00 for U,I, 00000 for
thermocouples J and K
0000.0 for Pt100
Highlight of the measured unit switched off, switched on switched on
Automatic compensation of
the terminal temperature/wire
resistance
switched off, switched on
switched on (for Pt100,
thermocouples J and
K), switched off for other
executions
Manual compensation value:
terminal temperature
wire resistance
in other cases
-20…60°C
0…20 Ω
0
40°C
0 Ω
0
Averaging time 0.5 s, 1 s, 3 s; 5 s, 10 s,
15 s, 20 s, 1 s
Upper overow of the
measurement -19999…99999 99999
Lower overow of the
measurement -19999…99999 -19999
Individual characteristic switched off, switched on switched off
Parameter aof the individual
characteristic -19999…99999 1
Parameter bof the individual
characteristic -19999…99999 0

18
6. ERROR CODES
After connecting the meter to the network, messages about errors may
appear. Causes of errors are presented below:
Overow of the upper value of the programmed indica-
tion range. In the option with Pt100, it also signals the
incorrect connection of the wire to the terminal 4.
Overow of the lower value of the programmed indica-
tion range.
ErrCA Loss of meter calibration values – In such a case, one
must contact an authorized service workshop.
ErrEE Incorrect values in meter conguration data. One must
set up again meter parameters by means of the eCon
software.
Action mode of the alarm output 1 n-on, n-off, on, off, h-on,
h-off n-on
Upper value of the alarm 1
switching - Aon -19999…99999 105% of rated value Un, In, or 200°C
Lower value of the alarm 1
switching - Aoff -19999…99999 100% of rated value Un, In, or 100°C
Delay of the alarm 1 switching
time 0…120 0 second
Action mode of the alarm output 2 n-on, n-off, on, off, h-on,
h-off n-on
Upper value of the alarm 2
switching - Aon -19999…99999 105% of rated value Un, In, or 200°C
Lower value of the alarm 2
switching - Aoff -19999…99999 100% of rated value Un, In, or 100°C
Delay of the alarm 2 switching
time 0…120 0 second

19
Measuring ranges:
INPUTS:
Measuring ranges of Un voltage:
-11... -10...60...66 mV
-1... 0... 10...11 V input resistance > 1 M
-11... 10... 10...11 V
Measuring ranges of In current:
-1...0... 20...22 mA input resistance 10   1%
3.6...4... 20...22 mA input resistance 10   1%
-22...-20... 20...22 mA input resistance 5   1%
Temperature measurement
through Pt100 - 50...400°C
current flowing through
the sensor < 300 mA
Resistance of wires connecting
the resistance thermometer to
the meter £10 (of one wire)
Temperature measurement
through thermocouple J - 50...1200°C
Temperature measurement
through thermocouple K - 50...1370°C
Preheating time 30 min.
Intrinsic error
(at manufacturer settings) (0.2% of the range 1 digit)
Additional errors in rated
operating conditions:
- compensation of reference
junction temperature changes 0.2% of the range
7. TECHNICAL DATA

20
- compensation of wire
resistance changes 0.2% of the range
- from ambient temperature
changes (0.1% of the range/10 K)
Averaging time £0.5s (1s by default)
Alarm outputs outputs of O/C type (30 V, 20 mA),
passive outputs acc. to EN 62053-31
Output to supply external
transducers 24 V  5%, 30 mA
Rated operating conditions:
- supply voltage 85...253 V a.c. (45...65 Hz) or d.c.
20...40 V a.c. (45...65 Hz) or d.c.
- ambient temperature - 10...23...55°C
- storage temperature - 25... + 85°C
- relative air humidity < 95% (inadmissible condensation
of water vapour)
- working position any
Sustained overload capacity
(measurement of voltage, current) 10%
Short duration overload
capacity (3 s):
- sensor inputs 30 V
- voltage input 10 Un
- current input 10 In
Readout field 5-digit three-colour LED displays:
- digit height: 14 mm,
- colours: green, orange, red
- indication range: -19999...99999
Ensured protection grade
from frontal side IP 65 acc. EN 60529