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IT375
User Manual
32 pgs1.49 Mb0
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Liquid Controls IT375 User Manual

INSTALLATION & O PERATION
MANUAL
MO D EL IT3 7 5
FIELD MOUNTED RATE INDICATOR AND TOTALIZER
February 2002
Model IT375

Contents

Pg. 2
CONTENTS
1. Introduction 3
1.1 Model Number Designation 4
1.2 Intrinsic Safety Considerations 4,5
2. Specification 6
3. Operation 7
3.1 Display 7
3.2 Test Mode 7
3.3 Filtering 8
3.4 Calculation of Rate and Total 9
3.5 Total Conversion 9
3.6 Frequency Cutoff 10
3.7 Linearizer 10
4. Programming 11
4.1 Program Steps 12,13
4.1 Flow Chart 14,15
5. Example 16
6. Versions 17
6.1 Battery Powered Version 17
6.2 DC Power Version 18
6.3 Relay and 4-20mA Output Version 19
7. Fl owmeter Inp ut 20,21,22
8. Intrinsic Safety Connections 23
8.1 Coils 23
8.2 Simple Apparatus 23
8.3 Namur Proximity Switches 23,24
8.4 Alarm Outputs 25
9. Installation 26
9.1 Wall Mounting 26
9.2 Panel Mount Version 26
9.3 Removing the Front Panel 27
9.4 The Main Electronics 27
9.5 Wiring 28
9.6 Terminal Designations 28
Index 29
Model IT375
Introduction
Pg. 3
1. INTRODUCT ION
The Model IT375 Rate Totalizer is a microprocessor-based instrument that accepts a sinewave or pulse input from Sponsler Company, Inc. Precision Turbine Flowmeters. The instrument displays 5 digits of Flowrate, 7 digits of Resettable Total and an Accumulated Total. The displayed rate and total values can be in different engineering units.
The instrument is compatible with a wide range of flowmeters. Links on the input board enable the circuit to be configured for millivolt signals, reed switches, pulse trains and most other signal types.
Although three different versions of the Model IT375 are available, No.3 is the standard.
1. A Battery Powered Version with no outputs.
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 timebase, K-factors, alarm and 4-20mA setpoints, decimal placements and filter constants.
The Model IT375 features many improvements, a few are listed below:
The output board can have both ALARMS and a 4-20mA OUTPUT. The voltage drop across the alarm outputs is only 0.8 VOLTS. The voltage supply for the DC and loop powered versions can go AS LOW AS 9 VOLTS. Overall lower current consumption with an improved battery life - 5 YEARS BATTERY LIFE is typical regardless of the duration of totalizing activity
4-20mA output ACCURACY is 0.05% of span and the LINEARITY is 0.05% of span at 25°C. The millivolt input can accept signals AS LOW AS 15mVp-p. Wide input frequency range - 0.01Hz to 10kHz. Wide Kfactor range - Kfactors from 0.000001 to 999,999 can be programmed. Available in a PANEL MOUNT version.
The Model IT375 Rate Indicator and Totalizer conforms to the EMC-Directive of the Council of European Communities 89/336/EEC and the following standards:
Generic Emission Standard EN 50081-1 Residential, Commercial & Light Industry Environment.
Generic Emission Standard EN 50081-2 Industrial Environment.
Generic Immunity Standard EN 50082-1 Residential, Commercial & Light Industry Environment.
Generic Immunity Standard EN 50082-2 Industrial Environment.
In order to comply with these standards, the wiring instructions in Section 9.5 must be adhered to.
Model IT375
Introduction
Pg. 4
Versions:
Mounting Options:
Intr insical ly Safe

Linearized

Model IT375i . 4 0 L
1.1 MODEL NUMBER DESIGNATION
The Model Number of the IT375 describes the power & output options installed and the mounting options.
SR = Strain relief cable entry PM = Panel Mount WM = Wall mount 4 = Turbine Adaptor(standard)
XP = Explosion proof
0 = Battery Powered Version 3 = DC powered with battery backup and alarm outputs 4 = Loop powered with 4-20mA output, alarm outputs and back up batteries
The above sample part number is the standard IT375 unit.

1.2 INTRINSIC SAFETY CONSIDERATIONS

The Model IT375i is certified for use in hazardous areas and has both CENELEC and CSA NRTL/C approvals. The Model IT375i certification details are:
CENELEC Approval: Kema. Type of Protection: Ex ia. Group: IIB.
Temperature Class: T4 at ambient temperature of 60°C.
CSA NRTL/C Approval File Number: 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 8 and in accordance with standards for wiring and installation in hazardous areas.

4-20mA/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.

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.
Model IT375
Introduction
Pg. 5
Fl owmeter Inp ut:
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 0.002uF and 0mH.
Output parameters are:
Uo = 10.0V Io = 9.0mA
Maximum allowed external capacitance is 60µF. Maximum allowed external inductance is 1.5H.
Model IT375
Specifications
Pg. 6
2. SPECIFICATION

General:

Display: LCD which is continuously powered. Resettable Total: 7 digits with 10mm (0.4") high digits. Resettable from front panel. Accumulat ed Total : Displayed when the ACCUM TOTAL button is depressed. Rate: 5 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. 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. Batt ery 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

DC Power/Alarm Version:

Outputs: Two optically isolated 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. Saturation: .8Volts Switching Power: 200mA. 30VDC maximum. DC Power Input: 9-28 Volt at 4mA maximum. Supply Backup: Lithium battery. Output Pulse Frequency: 500Hz Maximum Output 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. Turbine Meter Adaptor: An optional mounting stem is available for mounting the Model IT375 directly on turbine
flowmeters which have a 1" NPT boss or 1" BSP boss. Optional Mounting:
Wall: Universal mounting bracket supplied as standard. Pipe: A galvanized metal bracket is available which enables the Model IT375 to be attached to
a 2" vertical or horizontal pipe.
Panel: 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).
Model IT375
Operation
Pg. 7
ACCUM

3. OPERATION

The Model IT375 Rate Indicator and Totalizer accepts a sinewave 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 IT375 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 depressed.
The keys on the front of the IT375 have the following functions:
Depressing this key will display the
TOT AL
Ac cu mulated Total .

RESET

Depressing this key resets the Resettable Total at any time.
Depressing this key advances the Program Mode scroll

PROGRAM

3.2 TEST MODE

The IT375 has a Test Mode which can be entered by simultaneously depressing all 3 front panel keys. The tests and results are as follows:
Low Test Depressing 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 Depressing the RESET key, and depending on the programmed pulse output mode, the
high alarm output (if installed):
a. will go low if CAL0 = 0 (low and high alarms)
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 Depressing the PROGRAM key, all segments of the display will flash.
To exit the Test Mode, simultaneously depress all three front panel keys.
Model IT375
Operation
Pg. 8
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
3.3 FILTERING
Frequency fluctuations caused by pulsating flow through a flowmeter can interfere with the precision of the displayed rate. For this reason, the Model IT375 has a programmable digital filter which will average out these fluctuations and enable accurate, stable readings.
The degree of filtering of the input signal can be adjusted depending on the magnitude 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 allows each application to be addressed on it’s merits.
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 overdamped (slow) response to changes in the flowrate.
The following graph shows the time to reach 90% and 99% of a new reading for a step change in input signal.
Model IT375
Operation
Pg. 9
3.4 CALCULATION OF RATE
The flow rate, R, is calculated as follows:
f x H
R= K
where f is the input frequency in Hz (pulses/second). H is the timebase of rate and is 1 for seconds, 60 for minutes, 3600 for hours and 86,400 for days. K is the Kfactor (pulses/unit volume).
The Kfactor is flowmeter dependent 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 Kfactor and selects the timebase during the programming procedure.

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 engineering unit than the rate unit. Therefore, it only affects the totals (both resettable and accumulated).
Example:
If the Rate is required in gallons/minute:
1. The Kfactor 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 totalize in barrels.
Below is a table containing common units and their corresponding Total Conversion constants:
Rate/Unit Time Totals
Gallons (US)/Unit Time Litres/Unit Time Kilolitres 1000
Litres/Unit Time m3 1000 ml/Unit Time Litres 1000
Mgallons/Unit Time Acre-feet 0.32587
Equivalency ≤ 1 rate unit ÷ equivalency Equivalency ≥ 1 rate unit ÷ reciprocal of equivalency (1/equivalency)
Barrels (oil) 42.000
Total Conversion Factor
Model IT375
Operation
Pg. 10
Scaling Factor
Out 1
Out 2
Out 3
Out 4
Out 5
Frequency
0
Inp 1
Inp 2
Inp 3
Inp 4
Inp 5
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 totalized, 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 the lower a cutoff frequency the correspondingly longer response time for flow rate to update. For example, if the cutoff is set to 0.01Hz the Model IT375 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 IT375 must wait 100 seconds before it can determine that the flow has actually stopped.
3.7 LINEARIZATION
The following dia gram graphs the change in K-factor with frequency for a hypot hetical flowmeter. The heavy
black line re presents t he actual K-fac tor of t he flowmete r, while the light black line is the a pproximat ion used i n the instrument.
Up to 10 frequencies and K-factors can be programmed. Frequencies must be programmed in ascending
orde r. L inea r Int er pola tion i s use d be t ween poi nt s. If an i nput fre que nc y is l ess t han t he f irst (l owest) o r greater than the last (highest) pr ogr ammed frequency, the K-factor will remain a constant value.
Note: Display update time increases to 1sec if the linearizer is enabled in the battery powered version
of the Mod el IT375.
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