Contrec 202D User manual

202D-M-V3.1
FIELD MOUNTED
RATE TOTALISER
MODEL 202D
June 2017

202D-M-V3.1
IMPORTANT NOTICE
To preserve battery life, the batteries may have been
disconnected and may need to be reconnected. To do this
follow the steps outlined in section 9.3.
There are two battery packs (see the diagram in section 9.4)
and both packs must be connected.

202D-M-V3.1
CONTENTS
1. Introduction 1
1.1 Model Number Designation 3
1.2 Intrinsic Safety Approvals 4
2. Specification 6
3. Operation 8
3.1 Display 8
3.2 Test Mode 9
3.3 Filtering 10
3.4 Calculation of Rate and Total 12
3.5 Total Conversion 13
3.6 Frequency Cutoff 13
3.7 Linearisation 14
4. Programming 15
4.1 Program Steps 16
5. Example 19
6. Versions 20
6.1 Battery Powered Version 21
6.2 DC Power Version 22
6.3 Relay and 4-20mA Output Version 24
7. Flowmeter Input 26
8. Intrinsic Safety Connections 31
8.1 Coils 31
8.2 Simple Apparatus 32
8.3 Namur Proximity Switches 32
8.4 4-20mA Output 34
8.5 Alarm Outputs 36
9. Installation 38
9.1 Wall Mounting 38
9.2 Panel Mount Version 39
9.3 Removing the Front Panel 40
9.4 The Main Electronics 42
9.5 Wiring 43
9.6 Maintenance 43
9.7 Terminal Designations 44
Index

202D-M-V3.1

202D-M-V3.1
Introduction 1
1. INTRODUCTION
The Model 202Di Rate Totaliser is a microprocessor based instrument
which accepts a frequency or pulse input from a wide range of
flowmeters. The instrument displays flow Rate, a Resettable Total and
an Accumulated Total directly in engineering units.
The instrument is compatible with a wide range of flowmeters including
turbine, paddlewheel and positive displacement flowmeters.
Three different versions of the Model 202Di are available:
1. A Battery Powered Version with no output.
2. A DC Powered Version with either:
i. high and low flow alarms or
ii. a low flow alarm and pulse output.
3. A Loop Powered Version with 4-20mA output and alarms as above.
The instrument is fully programmable from the front panel; the user can
program scaling factors, decimal point positions, filter constants and timebase.
The Model 202Di Rate Totaliser conforms to the EMC-Directive of the Council of
European Communities 2014/30/EU, the LVD directive 2014/35/EU and the
following standards:
EN61326:2013 Electrical equipment for measurement, control
and laboratory use – EMC requirements :
Residential, Commercial & Light Industry
Environment & Industrial Environment.
EN61010:2010 Safety requirements for electrical equipment for
measurement, control, and laboratory use.
In order to comply with these standards, the wiring instructions in Section 9.5
must be adhered to.

202D-M-V3.1
Introduction 2
The following improvements have been made in the Model 202D:
ŸThe 202D output board can have both ALARMS and a 4-20mA OUTPUT.
ŸThe voltage drop across the alarm outputs in the 202D is ONLY 0.8 VOLTS.
ŸThe voltage supply for the DC and loop powered versions can go AS LOW
AS 9 VOLTS.
ŸThe 202D has an overall LOWER CURRENT CONSUMPTION than the
previous model with an IMPROVED BATTERY LIFE - the battery life in
the new model is typically 5 years regardless of the time the unit
spends in totalising mode.
ŸIn the 4-20mA output version of the 202D, the ACCURACY HAS BEEN
IMPROVED to 0.05% of span and the linearity to 0.05% of span at
25°C.
ŸThe millivolt input can accept signals AS LOW AS 15mV P-P.
ŸThe 202D has a WIDE FREQUENCY RANGE - 0.01Hz to 10kHz.
ŸThe 202D has a WIDER K-FACTOR RANGE - K-factors from 0.000001 to
999,999 can be programmed.
ŸFlowmeter Linearisation up to 10 points is now standard.
ŸUnlike the previous Model 202, the 202D has an additional mounting
option - it is available in a PANEL MOUNT version.

202D-M-V3.1
Introduction 3
1.1 MODEL NUMBER DESIGNATION
The Model Number of the 202Di describes the power & output options
installed and the mounting options.
Model 202Di . 2 3 C
Mounting options Version
0 No holes drilled for cable entry 0
Battery powered version
1Panel mount
2Wall mount (standard) 3DC powered with battery backup
4Turbine adaptor and alarm outputs
62" pipe mount (galvanised)
4Loop powered with 4-20mA
output, alarm outputs and backup
batteries
Approvals
CCSA USA/Canada approval
M ATEX/IECEx Approval

202D-M-V3.1
Introduction
4
1.2 INTRINSIC SAFETY APPROVALS
The Model 202Di is certified for use in hazardous areas and has IECEx, ATEX
and CSA US /C approvals.
The Model 202Di certification details are:
IECEx Approval IECEx BVS 15.0099X
Rating Ex ia IIB T4 Gb
ATEX Approval BVS 15 ATEX E 106 X
Rating II 2G Ex ia IIB T4 Gb
Ambient Temperature: Maximum ambient temperature of 60°C.
CSA NRTL/C Approval LR 104 840-5.
Type: Class 1, Groups C and D.
When installing in hazardous areas, the instrument must be installed
according to the guidelines in Section 2 and in accordance with standards for
wiring and installation in hazardous areas.
4-20 mA/DC Power
The input can be connected to IS circuits with the following maximum
values:
Ui = 28V
Ii = 93mA
Pi = 653mW
The internal capacitance and inductance seen on these terminals is 0.1uF
and 0mH.

202D-M-V3.1
Introduction 5
Relay Outputs
The outputs can be connected to IS circuits with the following
maximum values:
Ui = 28V
Ii = 93mA
Pi = 653mW
The internal capacitance and inductance seen on these terminals is 0.1uF
and 0mH.
Flowmeter Input
Entity parameters on the flowmeter enable connection to a wide
range of approved sensors.
Input parameters are:
Ui = 24V
Ii = 20mA
Pi = 320mW
The internal capacitance and inductance seen on these terminals is 0.02uF
and 0mH.
Output parameters are:
Uo = 10.0V (open circuit)
Io = 9.0mA (short circuit)
Po = 23mW
Maximum allowed external capacitance is 20µF.
Maximum allowed external inductance is 1.5H.

202D-M-V3.1
Specification
6
2. SPECIFICATION
General
Display: LCD which is continuously powered.
Resettable Total: 7 digits with 10mm (0.4") high digits. Resettable
from front panel.
Accumulated Total: Displayed when the ACCUM TOTAL button is
pressed.
Rate: 4½ digits with 8.5mm (0.33") high digits.
K-factor: The pulses per unit of measure (eg. pulses/gallon)
is programmable in the range 0.000001 to
999,999.
Calibration up to ten user selected points.
Decimal Points: Decimal point positions are fully programmable for
both rate and total.
Timebase: Rate can be displayed in units per second, minute,
hour or day.
Frequency Range: 0.01Hz to 10kHz.
Signal Type: Link settable for sinewave (15mV P-P minimum),
open collector, reed switch, pulse or Namur
proximity switch.
Battery Powered Version
Type: Two lithium battery packs.
Battery Life: 5 years typical.
Loop Powered 4-20mA Output Version
Scale: The 4mA and 20mA points are programmable.
Resolution and Linearity: 0.05% of span.
Accuracy: 0.05% of span at 25°C.
0.1% (typ) of span, full temperature range.
Update Time: 0.5 second.
Connection: Two-wire.
Loop Power Supply: 9-28 Volts.
Supply Backup: Lithium battery.

202D-M-V3.1
Specification 7
DC Power/Alarm Version
Outputs: Two open collector outputs suitable for driving
DC solenoids or external relays. The outputs can
be programmed to provide high and low flow
alarms or pulse output and low flow alarm.
Switching Power: 200mA. 30VDC maximum.
DC Power Input: 9-28 Volt at 4mA maximum.
Supply Backup: Lithium battery.
Pulse Duration: 1ms if CAL0 = 2 (unscaled pulse output).
If CAL0 = 1 (scaled pulse output) the duration
of the pulse automatically adjusts to the output
frequency:
a. 1ms if output > 50Hz.
b. 10ms if output = 5...50Hz.
c. 100ms if output < 5Hz.
Physical
Temperature: Operating temperature: -20°C to 60°C.
Dimensions: 97mm (3.8") high x 150mm (5.9") wide x
41mm (1.6") deep (cable glands not included).
Protection: Sealed to Nema 4X or IP67 standards.
Cable Entry: By cable glands.
Wall Mounting: Universal mounting bracket supplied as standard.
Pipe Mounting: A galvanised metal bracket is available which
enables the Model 202D to be attached to
a 2" vertical or horizontal pipe.
Turbine Meter Adaptor: An optional mounting stem is available for
mounting the Model 202D directly on turbine
flowmeters which have a 1" NPT boss or 1" BSP
boss.
Panel Mounting: Supplied with mounting brackets.
Terminals accessible from rear. The panel
mount version is not watertight.
Cutout: 141mm (5.6") wide x 87mm (3.4" high).

202D-M-V3.1
Operation
8
3. OPERATION
The Model 202D Rate Totaliser accepts a frequency or pulse input from a
wide range of flowmeters. The instrument is fully programmable with all
operating parameters and calculation constants programmable from the
front panel. The setup parameters are stored in a non-volatile memory and
are retained for at least 40 years in the event of a power loss.
3.1 DISPLAY
The Model 202D displays:
Rate
Resettable Total
Accumulated Total
Both the Rate and Resettable Total are displayed continuously. The
Accumulated Total is displayed only when the ACCUM TOTAL key is pressed.
The keys on the front of the 202D have the following functions:
Pressing this key will display the
Accumulated Total.
This key resets the Resettable Total
at any time.
This key is used during the Program
Mode.
RESET
PROGRAM
ACCUM
TOTAL

202D-M-V3.1
Operation 9
3.2 TEST MODE
The 202D has a Test Mode which can be entered by simultaneously pressing all
3 front panel keys. The tests are as follows:
Low Test By pressing the ACCUM TOTAL key, the low
alarm output (if installed) will go low. If a 4-
20mA option is installed, the output will go
to 4mA.
High Test By pressing the RESET key, and depending on the
programmed pulse output mode, the high
alarm output (if installed):
a. will go low if CAL0 = 0 (high alarm output).
b. will output 100ms pulses every 0.5 sec if CAL0
= 1 (scaled pulse output).
c. will output 1ms pulses every 0.5 sec if CAL0 =
2 (unscaled pulse output).
If a 4-20mA option is installed, the output will
go to 20mA.
Display Test By pressing the PROGRAM key, all segments of
the display will flash.
To exit Test Mode, all three front panel keys are pressed simultaneously.

202D-M-V3.1
Operation
10
3.3 FILTERING
Frequency fluctuations caused by pulsating flow through a flowmeter can
interfere with the precision of the rate. For this reason, the Model 202D has a
digital filter which will average out these fluctuations and enable accurate
readings.
The degree of filtering of the input signal can be adjusted depending on the
amount of fluctuation and the particular application. Values from 1 to 99 can
be programmed where 1 corresponds to no filtering and 99 corresponds to
heavy filtering. Such flexibility in filtering means that highly accurate and
stable readings can be obtained.
When programming the degree of filtering, it is advisable to start with no
filtering (the factor equals 1) and gradually increase until a steady reading is
obtained. It is important that the filtering is not too heavy because this will
cause an over-damped response.
The following graph shows the time to reach 90% and 99% of a new reading
for a step change in input signal.
Filter Factor vs Time to Reach New Reading
(for a step change in input signal)
0
20
40
60
80
100
120
0 10 20 30 40 50 60 70 80 90 100
Filter Factor
Time to Reach % of
New Reading (seconds)
90% of New Reading 99% of New Reading

202D-M-V3.1
Operation 11
3.4 CALCULATION OF RATE AND TOTAL
The flow rate, R, is calculated as follows:
where fis the input frequency in Hz (pulses/second).
His the timebase of rate and is 1 for seconds, 60 for minutes, 3600 for
hours and 86,400 for days.
Sis the scaling factor (pulses/unit volume).
The scaling factor, S, is equal to the K-factor of the flowmeter expressed in pulses
per unit volume. The K-factor is flowmeter dependant and is supplied with the
flowmeter. It will be either on a calibration certificate or stamped on the body of
the meter.
The user programs the scaling factor and selects the timebase during the
programming procedure.
R=f x H
S

202D-M-V3.1
12 Operation
3.5 TOTAL CONVERSION
The Total Conversion Factor is programmed to enable the rate to be displayed
in one engineering unit and the totals to be displayed in another. For
example, the rate can be displayed in gallons/minute and the totals in barrels.
The Total Conversion Factor is a division factor which is used to convert the
totals to a different unit. Therefore, it only affects the totals (both resettable
and accumulated).
Example.
If the Rate is required in gallons/minute:
1. The Scaling Factor would be programmed as pulses per gallon.
2. The Timebase would be programmed as minutes.
If the Totals are required in barrels:
1. The Total Conversion Factor is programmed as 42 because there are
42 gallons in a barrel. All totals will now totalise in barrels.
Below is a table containing common units and their corresponding
Total Conversion constants:
Rate/Unit Time Totals Total Conversion Factor
Gallons (US)/Unit Time Barrels (oil) 42.000
Litres/Unit Time Kilolitres 1000
Litres/Unit Time m31000
ml/Unit Time Litres 1000
Mgallons/Unit Time Acre-feet 0.32587

202D-M-V3.1
Operation 13
3.6 FREQUENCY CUTOFF
A frequency cutoff can be programmed below which flow rate is not registered.
Input frequencies at or below the cutoff are totalised, however, the rate is
displayed as zero.
The frequency cutoff has a default value of 0.25Hz. The cutoff should be left
as 0.25Hz unless the flowmeter in use has a lower frequency.
Note that a low cutoff frequency will result in a correspondingly low response
of flow rate update. For example, if the cutoff is set to 0.01Hz the 202D will
continue to display the flow rate for 100 seconds even if the signal stops. This
is because a cutoff frequency of 0.01Hz means that the time interval between
signals is 100 seconds (period = 1/frequency). Therefore, the Model 202D
must wait 100 seconds before it can determine that the flow has actually
stopped.

202D-M-V3.1
Operation
14
3.7 NON-LINEARITY CORRECTION
Non-linearity correction enables the instrument to correct for known non-
linearities in the flowmeter.
Up to 10 frequencies and scaling factors can be programmed. Data on
the flowmeter non-linearity can usually be supplied by the flowmeter
manufacturer in the form of a Calibration Certificate, and is the result of
individual tests on a flowmeter over a range of flowrates. The
Certificate will list a number of flowrates or frequencies with the
measured K-factor (e.g. pulses per gallon or litre) at each flowrate.
The following diagram graphs the change in scaling factor with frequency for
a hypothetical flowmeter. The heavy black line represents the actual scaling
factor of the flowmeter as read from the Calibration Certificate, while the
light black line is the approximation used in the instrument.
Linear Interpolation is used between points on the curve, except for
Factor 1 which maintains a constant value between Frequency 1 and any
Frequency below Frequency 1.
Note that the display update time will be increased to 1 second when the non
linear correction option is selected with the battery powered version of the
202D.
Sca l i ng
Fac t 1
Fac t 2
Fac t 3
Fac t 4
Fac t 5
F re qu e n c y
Fre q 1 F re q 2 Fre q 3 Fre q 4 Fre q 5

202D-M-V3.1
Programming 15
4. PROGRAMMING
The Model 202D is fully programmable with all parameters being stored in
non-volatile memory.
The Program Mode can be entered in one of two ways:
1. By removing the lower cover strip (ie. the dark grey strip along the
bottom of the enclosure) and replacing it the wrong side up. This brings
a small magnet on the inside of the cover strip in contact with a reed
switch inside the instrument.
2. By removing the front section of the enclosure which contains the main
processor board and batteries.
The PROGRAM switch is used to step through the program (CAL sequences)
and the ∆(ACCUM TOTAL) and > (RESET) keys on the front panel are used to
change and increment the flashing digits. Note that only flashing digits can
be changed.
Up to eighteen CAL steps are accessible depending on which options are
installed.
The CAL number is displayed on the lower display and the parameter is
displayed above it.
Parameters in Program Mode that consist of the two parts, whole numbers
and digits after the decimal point, are restricted to having a maximum of 6
significant digits. Therefore the number of significant digits entered in the
whole numbers determines the number of digits that are able to be entered
in the digits after the decimal point.
For Example
000001 in the whole numbers makes 00000 available after the decimal place.
000100 in the whole numbers makes 000 available after the decimal place.
010000 in the whole numbers makes 0 available after the decimal place.

202D-M-V3.1
Programming
16
4.1 PROGRAM STEPS
Step Comment
CAL 0 Pulse Output (applies to DC Power/Alarm version only).
0 = No pulse output, low and high alarms.
1 = Scaled pulse output and low alarm.
2 = Unscaled pulse output and low alarm.
CAL 1 Scaling Factor - whole numbers.
CAL 2 Scaling Factor - digits after the decimal point.
The scaling factor is the pulses per unit of measure
(e.g. pulses/litre, pulses/gallon, etc). The scaling factor
can be programmed in the range of 0.000001 -
999,999.
See Section 3.4.
CAL 3 Cutoff Frequency.
This determines the cutoff frequency in the range of 0.01
-0.99Hz. The default setting is 0.25HZ.
Note that care must be taken when programming this
value because a low value may cause a slow update time.
CAL 4 Decimal Point for Rate Display.
The flow rate can be displayed with 0, 1, 2 or 3 decimal
point places.
CAL 5 Timebase for Rate.
The rate can be displayed in units per second, minute, hour
or day.
0 = second
1 = minute
2 = hour
3 = day
CAL 6 Filter.
The filter constant for filtering the input signal.
1 No filtering.
to
99 Very heavy filtering.