Digital meters Sch20, Sch21, Sch22, Sch23

Panel digital meters Sch20, Sch21, Sch22, Sch23 are intended to measure current or voltage in DC circuits (for operation as part of technical means of nuclear power stations (NPP TM) and in other sectors of thhe industry).
The meters could be used complete with primary transducers for measurement non-electrical values if ranges of output electrical signal of primary transducers corresponds to the meters input signal ranges.
Input signal measurement ranges: 0–5 mA; 0–20 mA; 4–20 mA; 0–75 mV; 0–200 mV; 0–1 V; 0–10 V; 2–10 V.
The meters are powered from the DC source of (24 ± 4) V. In this case double pulsation amplitude shall not exceed 1.2 V.
Under climatic conditions the meters belong to articles of TV4.1 design (with expansion of Temperature range (operating) minus 10 to plus 50 °С) intended for operation in the atmosphere of type III according to GOST 15150-69. The meters meets the requirements for electromagnetic compatibility according to GOST R 50746-2000 imposed to group IV of NPP TM (technical means supplied to nuclear power stations and/or radiation hazardous facilities).
A level of industrial interferences when operating meters does not exceed values preset by GOST 30805.22-2013 for equipment of class B. For the level of protection against effect of solid bodies, the meters meet IP code according to GOST 14254-96.
Mean time between failures is 150000 hours min.
The meters service life is at least 15 years.
All meters are made in a metal case and fire-proof, have no mobile parts and provides resistance to mechanical effects according to group М40, seismic resistance of 9 points provided installation above zero position up to 10 m, 8 points at the installation level of up to 25 m according to GOST 17516.1-90, belong to category I of seismic resistance according to NP-031-01.
The meters are made in a metal case with panel fastening. The fastening design is rated for installation in the panel of 50 mm in thickness. According to the order, installation is possible in a panel with other thickness.
The meters intended for NPP may be used in the security system and systems of normal operation; depending on the order they meet safety classes 2, 3, 4 and have classification designation 2NU, 3NU according to OPB-88/97 NP-001-97.
Working conditions of operation:
– ambient air temperature of minus 10 to plus 50 °С;
– relative air humidity of 98 % max. at plus 35 °С;
– atmospheric pressure is 84...106.7 kPa;
– supply voltage of (24±4) VDC.
The meters provide the possibility to select the measurement range input signal and to change the range indications and name of measurement unit.
Meters Sch21.3, Sch22.4, Sch22.6, Sch23.3, Sch23.4, Sch23.6 provide the possibility to program thresholds for change in colour of indication of digital-analogue indicating device.
Meters Sch20.3, Sch21.7, Sch23.7, Sch23.8 provide the possibility to set areas of colour warning of digital-analogue indicating device, which are formed with a number of single indicators of each colour preset in case of order.





Specifications
Documentation

Measured value

Input signal measurement ranges

Group of input signal measurement ranges

design 1

(single polarity)

design 2

(double polarity)

DC voltage

0...75 mV

-75…0…75 mV

-

0...200 mV

-200…0…200 mV

-

0...1 V

-1…0…1 V

-

0...10 V

-10…0…10 V

I

2...10 V

-6…2…10 V

Direct current

0...5 mA

-5…0…5 mA

-

0...20 mA

-20…0…20 mA

ll

4...20 mA

-12…4…20 mA

Type

Maximum indication range digital indicating device*

Number of indicators of digital indicating device

Number of single indicators of digital-analogue indicating meters, indicator type**

Type of digital-analogue indicating device

Meters with digital indicating device

Sch20.1

-1999...9999

4

–

–

Sch21.1

-1999...9999

4

–

–

Sch21.2

-19999...19999

5

–

–

Sch21.5

-9999...9999

4 and sign “-”

–

–

Sch22.1

-1999...9999

4

–

–

Sch22.2

-19999...19999

5

–

–

Sch22.5

-9999...9999

4 and sign “-”

–

–

Meters with digital-analogue indicating device

Sch20.3

–

–

30, column

line

Sch21.3

–

–

31, column (mark)

line

Sch21.7

–

–

62, mark (column)

line

Sch23.3

–

–

61, column (mark)

arch

Sch23.7

–

–

102, mark (column)

arch

Meters with digital and digital-analogue indicating meters

Sch22.4

-1999...9999

4

25, column (mark)

line

Sch22.6

-9999...9999

4 and sign “-”

25, column (mark)

line

Sch23.4

-1999...9999

4

61, column (mark)

arch

Sch23.6

-9999...9999

4 and sign “-”

61, column (mark)

arch

Sch23.8

-9999...9999

4 and sign “-”

102, mark (column)

arch

* – indication range may be changed by the Customer with a setting panel;

** – factory setting is given without brackets

Type

Programmed parameters

Input signal measurement ranges

Indication range digital indicating device

Indicators illumination brightness

Thresholds of colour change and indication colour of digital-analogue indicating device

Type of digital-analogue indicating device indicator

Meters with digital indicating device

Sch20.1

+

+

+

-

-

Sch21.1

+

+

+

-

-

Sch21.2

+

+

+

-

-

Sch21.5

+

+

+

-

-

Sch22.1

+

+

+

-

-

Sch22.2

+

+

+

-

-

Sch22.5

+

+

+

-

-

Meters with digital-analogue indicating device

Sch20.3

+

-

+

-

-

Sch21.3

+

-

+

+

+

Sch21.7

+

-

+

-

+

Sch23.3

+

-

+

+

+

Sch23.7

+

-

+

-

+

Meters with digital and digital-analogue indicating meters

Sch22.4

+

+

+

+

+

Sch22.6

+

+

+

+

+

Sch23.4

+

+

+

+

+

Sch23.6

+

+

+

+

+

Sch23.8

+

+

+

-

+

Notes:

1 Sign “+” means that the parameter is programmable.

2 Sign “-” means that the parameter is non-programmable.

Order form

Scha – b – c – d – e – f – g – h – i – j

where Scha – meter type (by the Overall dimension, mm):

Sch20 – 50.25,

Sch21 – 100.25,

Sch22 – 100.50,

Sch23 – 100.100;

b – meter design by the view of indicating device, indication range digital indicating device and a number of single indicators of digital-analogue indicating device:

1 – digital indicating device with indication range –1999 ... 9999,

2 – digital indicating device with indication range ±19999,

3 – digital-analogue indicating device with a number of single indicators of up to 61,

4 – digital indicating device with the indication range –1999... 9999 and digital-analogue indicating device with a number of single indicators of up to 61,

5 – digital indicating device with indication range ±9999,

6 – digital indicating device with the indication range ±9999 and digital-analogue indicating device with a number of single indicators of up to 61,

7 – digital-analogue indicating device with a number of single indicators over 61,

8 – digital indicating device with the indication range ±9999 and digital-analogue indicating device with a number of single indicators over 61.

с – structural meter design:

G – horizontal;

V – vertical

d – measurement range input signal

e – indication range

f – measurement unit of the displayed value

g – front frame colour:

W – white,

Gr – grey,

B – black

h – front frame colour:

W – white,

G – grey,

B – black

i – colour of indicators of digital indicating device:

R – red,

Y – yellow,

G – green

j – parameters of digital-analogue indicating device:

– thresholds of colour change and indication colour (R – red, Y – yellow, G – green) For the meters Sch21.3, Sch22.4, Sch22.6, Sch23.3, Sch23.4, Sch23.6 (from the beginning of the indication range),

– number and colour (R – red, Y – yellow, G – green) of single indicators of each alarm area For the meters Sch20.3, Sch21.7, Sch23.7, Sch23.8 (from the beginning of the indication range).

Unused parameter i in the order formula is replaced with sign “x”.

Unused parameters c and j are not specified.

The following is additionally specified:

1) safety class, classification designation according to OPB-88/97 NP-001-97 (2NU, 3NU or 4);

2) thickness of a panel for installation of the meter if it differs from 50 mm;

3) language if marking and (or) Operation Manual, Calibration Method shall be prepared in English, Russian is by default;

4) number of copies of Operation Manual, Calibration Method.

Sch meter type

Full reference designation code parameter

b

с

d

e

f

g

h

i

j

Sch20

1

–

+

+

+

+

+

+

–

3

G (V)

+

+

+

+

+

–

+

Sch21

1

–

+

+

+

+

+

+

–

2

–

+

+

+

+

+

+

–

3

G (V)

+

+

+

+

+

–

+

5

–

+

+

+

+

+

+

–

7

G (V)

+

+

+

+

+

–

+

Sch22

1

–

+

+

+

+

+

+

–

2

–

+

+

+

+

+

+

–

4

G (V)

+

+

+

+

+

+

+

5

–

+

+

+

+

+

+

–

6

G (V)

+

+

+

+

+

+

+

Sch23

3

–

+

+

+

+

+

–

+

4

–

+

+

+

+

+

+

+

6

–

+

+

+

+

+

+

+

7

–

+

+

+

+

+

–

+

8

–

+

+

+

+

+

+

+

Notes

Sign “+” means a parameter is available in the order formula.

Sign “–” means that no parameter is available in the order formula.

 

Ordering examples

Sch22.2–0...5 mA – minus 20.00...plus 50.00-°С-W-B-G, TU 25-7504.210-2010, safety class – 2N.

Sch22.2, Overall dimension is 100х50 mm, digital indicating device with maximum value of indication range 19999, input signal range 0...5 mA, indication range minus 20 ... plus 50, measurement unit – °С, front panel colour – white, front frame colour – black, indication colour – green, safety class – 2N.

Sch22.4.G-0...5mA-minus 20.00...plus 50.00-°С-W-B-R-minus 20 (R), minus 10 (Y), 0 (G), plus 30 (Y), plus 40 (R), TU 25-7504.210-2010, safety class – 4.

Sch22.4, Overall dimension is 100х50 mm, digital and digital-analogue indicating device, structural design - horizontal, measurement range input signal of 0...5 mA, indication range minus 20 ... plus 50, measurement unit – °С, front panel colour – white, front frame colour – black, digital indicators colour – red, thresholds of indication colour change – minus 20 – red, minus 10 – yellow, 0 – green, plus 30 – yellow, plus 40 – red, safety class – 4.

 

Сertificate of conformity (pdf, 830.4 Kb )   View   Download
Manual (pdf, 4 Mb )   View   Download
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