B&C Electronics CL 7685 Instruction Manual

CERT. N. 9115 BCEL

INSTRUCTION MANUAL

UNI EN ISO 9001:2000

CL 7685

RESIDUAL CHLORINE

CHLORINE DIOXIDE - D. OZONE

MICROPROCESSOR CONTROLLER

* potentiostatic *

Range: 0/2.000/20.00 PPM

Temperature range: -2/+52 °C

Power supply: 110/220 Vac

Software: R:2.4 x

Option

S/N

REP N°

Cod. 28006765 - Rev. D - 11/06

B&C Electronics Srl - Via per Villanova 3 - 20040 Carnate (Mi) - Italy - P.IVA 00729030965
Tel [phone] - Fax [phone] – [e-mail] - www.bc-electronics.it

B&C Electronics CL 7685

Index

1 GENERAL .........................................................................................................................................4

1.1 Functional specifications ..........................................................................................................5

1.2 Physical description..................................................................................................................8

2 SPECIFICATIONS............................................................................................................................9

3 INSTALLATION ............................................................................................................................14

3.1 Physical installation................................................................................................................14

3.2 Electrical installation ..............................................................................................................14

3.3 Operating the system ..............................................................................................................17

4 KEYBOARD ...................................................................................................................................18

5 READOUT SEQUENCES ..............................................................................................................19

6 CALIBRATION SEQUENCES ......................................................................................................23

6.1 Operating mode selection .......................................................................................................23

6.2 Zero and sensitivity calibration ..............................................................................................24

6.3 Temperature calibration..........................................................................................................28

6.4 Set-point A/B setting ..............................................................................................................29

6.5 Alarm setting ..........................................................................................................................33

6.6 Cleaning function ...................................................................................................................34

7 CONFIGURATION.........................................................................................................................37

7.1 Keyboard locked/unlocked .....................................................................................................37

7.2 LCD display contrast ..............................................................................................................37

7.3 Access number........................................................................................................................38

7.4 Type of measuring ..................................................................................................................38

7.5 Input range..............................................................................................................................38

7.6 Autorange ...............................................................................................................................39

7.7 Software filter .........................................................................................................................39

7.8 Cell polarization voltage.........................................................................................................39

7.9 Calibration mode ....................................................................................................................39

7.10 Temperature coefficient..........................................................................................................40

7.11 Input related to analog output n°1 (option 091.3711) ............................................................40

7.12 Analog output n°1 range.........................................................................................................40

7.13 Input related to analog output n°2 (option 091.3711) ............................................................41

7.14 Analog output n°2 range.........................................................................................................41

7.15 Set-point A operating mode....................................................................................................42

7.16 Set-point A function ...............................................................................................................42

7.17 Set-point B operating modE ...................................................................................................42

7.18 Set-point B function................................................................................................................43

7.19 Alarm on Set-point A .............................................................................................................43

7.20 Alarm on Set-point B..............................................................................................................43

7.21 Alarm relay contact function ..................................................................................................44

7.22 Alarm type ..............................................................................................................................44

7.23 alarm flashing frequency ........................................................................................................44

7.24 Cleaning function ...................................................................................................................45

7.25 Cleaning time (relay D on) .....................................................................................................45

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B&C Electronics CL 7685

7.26 Holding time ...........................................................................................................................45

7.27 New access number ................................................................................................................45

8 CALIBRATION...............................................................................................................................47

8.1 Electrical calibration...............................................................................................................47

8.2 Chemical calibration...............................................................................................................47

9 PREVENTIVE MAINTENANCE...................................................................................................48

WARRANTY CERTIFICATE...............................................................................................................52

REPAIRS................................................................................................................................................52

TECHNICAL SUPPORT .......................................................................................................................53

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B&C Electronics CL 7685

1 GENERAL

This series of controllers with built-in microprocessor forms an advanced system of measurement and
regulation of pH - ORP - Conductivity - Dissolved Oxygen - Chlorine in industrial processes.

These instruments are the result of all of B&C Electronics know-how built up over more than 30 years
of experience in the field of industrial electrochemical analysis.
We have continually developed and updated these products keeping in mind the maximum
consideration for quality, reliability, completeness of functions, simplicity of handling, and also the
cost.

The computing capability and the versatility of the microprocessor are accompanied by friendly
software specially designed to make the use of the instrument, the programming of its functions,
routine checks and calibrations easily accessible even for an untrained operator.

The alpha-numeric backlit liquid crystal display helps the operator supplying him with all the
information on functioning and on operating, while the software suggests possible steps for calibration
and set-up.

The display supplies, at the same time as the measurement, an indication of present status of the output
relays and of the output current.

For a higher level of checks, the display gives an indication of the operating conditions of the
electrochemical sensors, the current status of the calibrations, set points and analog output.

The user friendly operation of the instrument saves the operator feats of memory and continual
reference to the instruction manual.

All operations are carried out using the five key pads on the front panel, for the mode selection, the
input of calibration and set point data and the setting-up. (Fig. 1)

There are no knobs or switches to manipulate in order to operate the unit. This makes the instrument
rugged and more corrosion resistant.

A non-volatile EEPROM memory assures measurement parameters are maintained in the event of a
power interruption.

The software is provided with a "watch-dog" check for correct functioning of the programs.

The electrical circuit is protected by a device which comes back into operation automatically following
an overload or a wiring error.

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B&C Electronics CL 7685

1.1 FUNCTIONAL SPECIFICATIONS

Input

The instrument accepts input from potentiostatic sensor for Active Chlorine, Chlorine Dioxide and
D.Ozone measuring.

A second input is provided for 3 wires Pt100 Temperature sensor.

Temperature compensation

The unit is supplied with manual or automatic Temperature compensation and Temperature
information may be displayed on LCD.
The instrument detects the absence or malfunctioning of the Temperature sensor and automatically
switches to manual operation mode.

Measuring ranges

The unit provides an input range which may be selected from 0/1.999 or 0/19.99 PPM.
Auto ranging function may be activated for the measuring range 0/1.999 PPM.
Auto ranging allows the operator to calibrate the unit in the low range, against a high concentration of
standard solution.

Analog output

Either a 0/20 mA or 4/20 mA isolated output may be selected, provided for interface with computer or
data loggers.
A special routine allows selection of the analog output range.
If the instrument is programmed for high range, the output may be set anywhere from 0/20.00 PPM.
If low range is selected, the output may be set anywhere from 0/2.000 PPM.

Control relays

The monitor is equipped with two SPDT control relays.

These output relays may be used in a variety of ways, and the function of each relay is programmable
by operator.
Control relays can be used in one of 3 different output modes: on/off, pulse width modulation and
pulse frequency modulation.

The on/off mode of operation is used for simple control or for alarm purposes. Each control relay may
be programmed for set-point, high/low, hysteresis, delay time for actuation.

The proportional mode of operation is used for more accurate control.
Each control relay may be programmed for set-point, high/low, proportional band, Frequency or Width
modulation.
The full display indicates the current setting and the current status of each relay.

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B&C Electronics CL 7685

Alarm relay

The unit contains a SPST relay designated as an alarm relay.

This relay may be used to warn of various conditions that might indicate operational problems.
The relay will activate on either high or low concentration conditions, or on failure of the control
relays to maintain proper control.

This relay may be programmed for either normal or fail-safe operation.

The software R:2.4x provides the additional function of the selectable continuous/flashing alarm and
the selectable flashing frequency.

Cleaning function

The unit contains a SPST relay designed for the auto clean cycle.

It's possible manually activate the cleaner to test its operation.

The operator can change the frequency of cleaning.

The configuration routine selects:

- auto/manual operation

- the cleaning time

- the holding time.

During cleaning and holding time:

- messages are flashing

- analog output is held constant

- set-points and alarm relays are deactivated.

Operating mode

The instrument is provided with 3 programmable modes of operation.

- Automatic operation (AUTO):

The Automatic mode is the normal operation mode of the unit.

- Measuring operation (MEAS.):

In this mode of operation the display indicates only the concentration, the analog output is active but
the control relays are deactivated.
This would be the mode to use if the relays are not being used for alarm or control functions.
The measuring mode of operation is useful for start up or for manual operation of disinfection plants.

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B&C Electronics CL 7685

- Simulated operation (SIM.):

In this operating mode the users choose the displayed value by means of up/down keys.
The unit maintains the set point, alarm and analog output parameters in order to test the plant.

The display does not indicate the measuring units (PPM) and access to calibration of the parameters is
not allowed.
The message "SIM" is shown on the display, indicating the current operation mode of the instrument.

Calibration mode

The instrument may be programmed for the immediate or postponed calibration.

The immediate calibration mode allows the operator to calibrate the unit immediately against a field
measurement on the same sample that the sensor is measuring.

The postponed calibration mode allows the operator to calibrate the unit against a laboratory
measurement on the same sample that the sensor is measuring.
The calibration may be performed later even if the sample concentration has changed.

Software filter

The unit is provided with a dual programmable software filter, to be inserted when the readout is not
stable.
The filter values can be selected separately for the small or large signal variations.

Configuration

The electronics for the monitor is designed to be as flexible as possible.
A number of programming functions are provided in the Configuration menu, protected by an access
number, which must be entered to allow changes in this setting.
The routine allows the programming of a custom access number.

Front panel lock

The keys on the front panel of the monitor can be used for changing the display, for calibrations and
set-point adjustments.

When the monitor is shipped, all functions are accessible.
However, the adjustment and calibration functions may be locked in order to prevent unauthorized
adjustments to the instrument.

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B&C Electronics CL 7685

Options

091.3711 Dual isolated and programmable output
The operator may select an output for Temperature.

091.404 24 VAC power supply.

091.4143 9/36 VDC power supply.

091.701 RS232 isolated output
The output sends the data (PPM,°C) to the serial port of the computer.

1.2 PHYSICAL DESCRIPTION

The controller enclosure is designed for surface or panel mounting.

It consists of an anodized aluminium case built according to the standard DIN 43700, with an
aluminium panel coated with scratch-proof and non-corrosive polycarbonate membrane.

A transparent waterproof front door SZ 7601 can be added to the housing, in order to protect the unit
from excessive moisture or corrosive fumes.

Signal and power connections are made by using two special extractable terminal blocks placed in
the back of the instrument.
This makes wiring, installation and general maintenance of the probes and other devices easier.

The package is supplied complete with fixing clamps for panel-mounting.

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B&C Electronics CL 7685

2 SPECIFICATIONS

The DEFAULT values are correspondent to the factory calibration values.

Parameters marked by " * " can be modified in the Configuration procedures.

Default

OPERATING MODE

Automatic/Measuring/Simulation Auto

MEASURING TYPE

* Chlorine/Chlorine dioxide/D. Ozone Chlorine

INPUT SCALES

Input range: 2.000/20.00 PPM 20.00

Display resolution at 20 °C: 1/2000

Software filter 90% RT:
* LARGE signal: 0.4/20,0 s 2.0 s
* SMALL signal: 0,4/20,0 s 10,0 s

Current at 20 °C: 250/5000 nA/PPM 2000 nA/PPM
Cell Sensitivity: 12.5/250% 100%
Zero: adjustable 0 µA
* Comp. Temp. Coefficient Cl/ClO2: 0/4.0 % / °C 2.0% / °C
* Comp. Temp. Coefficient O3: 0/4.0 % / °C 2.5% / °C
* Polarization Voltage: adjustable -200 mV

TEMPERATURE

Input: RTD Pt100
Connection: 2/3 wires
Measuring and compensation range: -2/+52 °C
Resolution: 0.1 °C
Zero adjustment: +/- 2°C 0 °C
Manual Temperature compensation: 0/50 °C 20 °C

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B&C Electronics CL 7685

SET A/B

* Selectable actions:
ON-OFF
PFM - Pulse frequency proportional
PWM - Pulse width proportional

* Action: ON-OFF SET B
Value: 0/2.000 - 0/20.00 PPM (as selected scale) 0 PPM
Hysteresis: 0/0.200-0/2.00 PPM (as selected scale) 0.2 PPM
Delay: 0/99.9 s 0.0 s
* Function: HI/LO (Max/min) LO

* Action: PFM SET A
Value: 0/20.00 PPM (as selected scale) 0 PPM
Proportional band: 0/0.200 - 0/2.00 PPM 0.2 PPM
(as selected scale )
Pulse max. Frequency: 0/120 pulse/minute 100 p/m
Pulse width: 0.1 s
* Function: HI/LO (Max/min) LO

* Action: PWM
Value: 0/0.200 - 0/20.00 PPM (as selected scale) 0 PPM
Proportional band: 0/0.200 - 0/2.00 PPM 0.2 PPM
(as selected scale)
Pulse width: 0/99.9 s 20.0 s
Min. pulse width: 0.3"
* Function: HI/LO (Max/min) LO

Relay Contacts: SPDT 220 V 5 A Resistive load

ALARM (RELAY C)

High value: 0/2.000 - 0/20.00 PPM (as selected scale) 20.00 PPM
Low value: 0/2.000 - 0/20.00 PPM (as selected scale) 0.00 PPM
Delay: 0/99.9 s 0.0 s
* Alarm on max. SA: ON/OFF OFF
* Max. time SA: 0/60 minutes 60 min
* Alarm on max. SB: ON/OFF OFF
* Max. time SB: 0/60 minutes 60 min
* Contact type: ACT/DEA ACT
* Alarm type: CONT./FLASH CONT
* Flashing frequency: LO (approx. 0.3 Hz duty cycle) ME
ME (approx. 0.6 Hz duty cycle)
HI (approx. 1.2 Hz duty cycle)

Relay Contact: SPST 220 V 5 A Resistive load

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B&C Electronics CL 7685

CLEANING FUNCTION (RELAY D)

* Action: Disable/Manual Clean/Auto+Manual Clean Disable

Auto Clean:
Repetition time: 0.1/24.0 h 24.0 h
* Cleaning time: 0.5/60.0 s 15.0 s
* Hold time: 0.1/20.0 minutes 3.0 min.

Relay contacts: SPST

ANALOG OUTPUT Nr. 1

* Current range: 0-20/4-20 mA 0/20 mA
* Point 1 corresponding to 0 mA or 4 mA
RANGE 20.00 PPM: 0.00/20.00 0.00 PPM
RANGE 2.000 PPM: 0.000/2.000 0.000 PPM
TEMPERATURE: 0.0°C/50.0°C (Option 091.3711) 0.0 °C
* Point 2 corresponding to 20 mA
RANGE 20.00 PPM: 0.00/20.00 20.0 PPM
RANGE 2.000 PPM: 0.000/2.000 2.000 PPM
TEMPERATURE: 0.0°C/50.0°C (Option 091.3711) 50.0 °C
Response time: 10 s for 98 %
Isolation: 250 Vca
Rmax: 600 Ω

ANALOG OUTPUT N°2 (Only for Option 091.3711)

* Current range: 0-20/4-20 mA 0/20 mA
* Point 1 corresponding to 0 mA or 4 mA
RANGE 20.00 PPM: 0.00/20.00 0.00 PPM
RANGE 2.000 PPM: 0.000/2.000 0.000 PPM
TEMPERATURE: 0.0 °C/50.0 °C 0.0 °C
* Point 2 corresponding to 20 mA
RANGE 20.00 PPM: 0.00/20.00 20.00 PPM
RANGE 2.000 PPM: 0.000/2.000 2.000 PPM
TEMPERATURE: 0.0 °C/50.0 °C 50.0 °C
Response time: 10 s for 98 %
Isolation: 250 Vca
Rmax: 600 Ω

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B&C Electronics CL 7685

SERIAL COMMUNICATION (Option 091.701)

Baud Rate: 4800 bit/s
Nr. of bit: 8 bit
Nr. of stop bit: 1 bit
Parity: None
Isolated from measure circuits
Example of data sent: ± 20.00 PPM ± 50.0 °C
Data sent every: 0.4 s

PARAMETERS ON CONFIG. BLOCK (See for *)

Free calibration (access code not required):
Keyboard Lock/Unlock Unlock
LCD contrast (0/7). 4

Under access code number: (0) 0
Type of measure:Cl/ClO2/O3 Cl
Measuring range: 2.000/20.00 20.00 PPM
Auto ranging: On/Off Off
LARGE software filter response time 2.0 s
SMALL software filter response time 10.0 s
Polarization - 200 mV
Immediate/postponed calibration mode Immed.
Temperature Coefficient 2.0%
Input connected to the output N°1 PPM
Analog output N°1 range (0/20 4/20 mA) 0/20 mA
Point 1 corresponding to 0 mA or 4 mA 0.00 PPM
Point 2 corresponding to 20 mA 20.00 PPM
Input connected to the output N°2 PPM
Analog output N°1 range (0/20 4/20 mA) 0/20 mA
Point 1 corresponding to 0 mA or 4 mA 0.00 PPM
Point 2 corresponding to 20 mA 20.00 PPM
Action of relays A (On-Off/PFM/PWM) PFM
Function of the A (HI/LO) LO
Action of relays B (On-Off/PFM/PWM) On-Off
Function of the B (HI/LO) LO
Alarm on max. operating time of SA Off
Max. operating time of SA for alarm 60 m
Alarm on max. operating time of SB Off
Max. operating time of SB for alarm 60 m
Alarm relay status (ACT/DEA) ACT
Alarm type Cont
Flashing frequency ME
Cleaning function (Auto/Manual/Disabled) Disabled
Cleaning time: 0.5/60.0 s 15.0 s
Holding time: 0.1/60.0 minutes 3.0 min.
Access number: 0/999 0

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B&C Electronics CL 7685

GENERAL SPECIFICATIONS

Alphanumeric display: 1 line x 16 characters
Response time to 98% of value changing,
with TC=2% / °C - T=20 °C - S=100% :
< 5 s for HI range
< 15 s for LO range

Operating Temperature: 0/50 °C
Humidity: 95% without condensate
Power supply: 110/220 Volt ac +/- 10% 50/60 Hz
Isolation: 4000 V between primary and secondary (IEC 348)
Power: 5 VA max.
Terminal block: extractable
Weight: 850 g
Dimensions: 96 x 96 x 155 mm

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B&C Electronics CL 7685

3 INSTALLATION

3.1 PHYSICAL INSTALLATION

The controller may be installed close to the areas being monitored, or it may be located some distance
away in a control area.

The enclosure is designed for panel-mounting.
It should be mounted on a rigid surface, in a position protected from the possibility of damage,
excessive moisture and corrosive fumes.

The cable from the probe must be protected by a sheath and not installed near power cables.

Interruption on cables must be avoided or carried out by high insulation terminals.

When installing "in line" electrodes it is suggested to follow the specific instructions given by the
sensor's manufacturer.

3.2 ELECTRICAL INSTALLATION

All connections within the controller are made on detachable terminal strips located on the rear side.
(Fig. 2)

All power and output-recorder connections are made at the 13_ pin terminal strip, while input signal
connections are made at the 12_ pin terminal strip.

The electrical installation consists of:

Connecting the power

- Connect ground to terminal 4;

- connect ac power to 1 - 2 terminals if power voltage is 110 Vac;

- connect ac power to 1 - 3 terminals if power voltage is 220 Vac;

- if 091.404 option is installed, connect 24 Vac to 1-3 terminals.

WARNINGS:

- Power the device by means of an isolation transformer;

- avoid mains voltage from an auto-transformer;

- avoid mains voltage from a branch point with inductive loads;

- separate power supply wires from signal cables;

- control the mains voltage value.

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B&C Electronics CL 7685

Connecting the sensor

- Sensor cabling is a critical part of the whole system;

- use original cable supplied with the sensor;

- avoid interruption on the cable.

- Connect the White wire (Counter electrode) to the terminal 17 marked EL;

- connect the Black wire (Measuring electrode) to the terminal 18 marked IN;

- connect the shield (Reference electrode) to the terminal 19 marked R.

Connecting alarms, pumps, valves

The output connections referred to Set-point SA and Set-point SB are made at terminal strip and they
consist of two independent SPDT relays corresponding to Regulator A and Regulator B .

The output connection referred to alarm consists of SPST relay corresponding to Alarm C.

The output connection referred to auto-clean consists of SPST relay corresponding to Auto clean D.

Control relay "A" Set-point "SA"

Terminal 6_ marked C_ common contact
Terminal 5_ marked NO_ normal open contact
Terminal 7_ marked NC_ normal closed contact

Control relay "B" Set-point "SB"

Terminal 9_ marked C_ common contact
terminal 8_

marked NO_ normal open contact

terminal 10_ marked NC_ normal closed contact

Alarm relay "C"

Terminal 12_

marked C_ common contact

Terminal 11_ marked NO_ normal open contact

Auto clean relay "D"

Terminal 12_ marked C_ common contact
Terminal 13_ marked NO_ normal open contact

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B&C Electronics CL 7685

Connecting a recorder

A current output for a remote recorder or P.I.D. regulators is available on terminals 14-16.

Connect the recorder high (+) to terminal 14
Connect the recorder low (-) to terminal 16

Series connection is required for driving more loads having a total input Resistance lower than 600 Ω.

If the 091.3711 dual output option is installed, a second isolated and programmable output is available
between 15-16 terminals.
Output N°1 and Output N°2 are isolated and selectable 0/20 or 4/20 mA.

Connecting the RTD

The instrument has the automatic Temperature compensation carried out by means of RTD Pt100.
To operate the automatic Temperature compensation, connect the RTD as shown in the "connection"
figure. (Fig. 2)

A three wire connection is suggested to achieve an accurate compensation over a long distance
between the sensor and the controller.

3-wire connection

- connect the terminal of RTD to terminal 23 of the meter;

- connect the common terminal of RTD to terminals 24 - 25 of the meter;

- the 3 wire-cable must not be interrupted on the overall length.
If an extension is needed, the cable must be fastened to the high insulation terminal strip;

- keep the cable away from power wires.

The RTD connection as above described allows the controller to provide a digital readout of
Temperature.

If the Temperature sensor is not connected or damaged, the unit will operate in manual Temperature
compensation automatically.

2-wire connection

- connect the Pt100 to terminals 23 - 24 ;

- install a jumper to terminals 24 - 25.

Checking

Before connecting the system to the power supply:

- check that all cables are properly fastened to prevent strain on the connections

- check that all terminal-strip connections are mechanically and electrically sound.

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