JENCO 6308CT User manual

OPERATION MANUAL
JENCO MODEL 6308CT
MICROCOMPUTER BASED
Conductivity/TDS & Temperature
CONTROLLER
JENCO ELECTRONICS,LTD.
MANUFACTURER OF PRECISION INSTRUMENTS

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CONTENTS page
I. INITIAL INSPECTION and ASSEMBLY 2
MOUNTING PROCEDURE 2
II. GENERAL INTRODUCTION 4
III. USING THE JENCO MODEL 6308CT 5
A.FRONT PANEL 5
B.NORMAL MODE DISPLAY 6
C.REAR CONNECTORS 7
D.TURNING ON/OFF THE INSTRUMENT 8
PROBE HANDLING AND MAINTANCE 9
IV. MODEL 6308CT MODES 10
A. NORMAL MODE 10
B. CALIBRATION/SETTING MODE 13
a.PASSWORD CHECK PAGE 14
b.USER SETTING PAGE 15
c.CONDUCTIVITY CALIBRATION PAGE 15
d.CONDUCTIVITY CONTROL SETTING PAGE 18
e.CURRENT SETTING PAGE 19
f.TEMP. CONTROL SETTING PAGE 20
V. CONTROLLING THE RELAYS 21
A. ISOLATION VOLTAGE 21
B. OUTPUT LOAD 21
C. RELAY ACTION, SETPOINT, HYSTERESIS
MODE & HYSTERESIS VALUE 21
D.CONDUCTIVITY/TDS RELAYS 22
E.TEMPERATURE RELAY 23
VI. 4-20 mA OUTPUT 23
A.ISOLATION VOLTAGE 23
B.OUTPUT LOAD 23
C.CONDUCTIVITY OR TDS LINEAR OUTPUT 23
VII. RS485 INTERFACE OPERATION 25
A.INTRODUCTION 25
B.PREPARING THE METER 25
VIII.ERROR DISPLAYS AND TROUBLESHOOTING 26
IX. SPECIFICATION 27
X. WARRANTY 29

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I. INITIAL INSPECTION and ASSEMBLY
Carefully unpack the instrument and accessories. Inspect for
damages made in shipment. If any damage is found, notify your
Jenco representative immediately. All packing materials should be
saved until satisfactory operation is confirmed.
MOUNTING PROCEDURE
1. Make a cutout on any panel, with a thickness of 1/16 in. (1.5 mm)
to 3/8 in. (9.5mm).
2. Remove the mounting assembly from the controller and insert the
controller into the cutout.
3. Replace the mounting bracket assembly onto the controller and
secure the controller to the mounting panel.
Warning:
If the equipment is used in a manner not specified by the
manufacturer, the protection provided by the equipment may be
impaired.
3.66" 0.04
0.00
93.00mm
1.00
0.00 93.00mm
3.66" 0.00
0.00
1.00
0.04
0.04"R(1.0mm) MAX.
PANEL CUTOUT DIMENSIONS

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Cleaning the instrument:
1. Be sure to remove the power before attempting to clean the
meter.
2. Use a lint free cloth and clean water or neutral detergent.
3. Wipe the outer surface of the instrument only.
4. Wipe-dry the instrument before powering again.

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II. GENERAL INTRODUCTION
The Jenco Model 6308CT (Conductivity and Temperature) System,
is a rugged microprocessor based instrument assembled in a
watertight ¼ DIN case, designed for use in laboratories and process
control applications.
The model 6308CT microprocessor allows the user to easily
recalibrate the parameters for the probes. The Conductivity system
requires only a single calibration. The microprocessor also performs
a self-diagnostic routine every time you turn on the unit providing
you with basic information about the stability of the instrument.
The system simultaneously displays Conductivity, Temperature,
cell constant or TDS factor, relay status and mA output in one LCD
graphic screen. This system uses a two-wire or four-wire type
sensor for the conductivity and a precise thermistor for
temperature, providing you with accurate readings for all your
measurements.
The model 6308CT is equipped with three relays: two
programmable High/Low control relays for conductivity/TDS and
one programmable High/Low control relay for temperature. All
relays are hysteresis driven and configurable to CENTER or EDGE
mode. The system also has an isolated 4-20mA analog output, offset
and span configurable for Conductivity/TDS display.
The model 6308CT comes with a RS485 interface which can easily
let the user log all data (from multiple model 6308 or 6309) with
an IBM©PC/AT compatible computer. For advanced users, the
model 6308CT may also be remotely controlled from main display
mode to all calibration/setting modes.

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III. USING THE JENCO MODEL 6308CT
A. FRONT PANEL
1. The [MODE/-] key.
1a. In Normal mode this key
will change the display to
Conductivityor TDS.
1b. In Calibration/Setting
mode this key will move
to the next digit of the
current active parameter.
1c. In Calibration/Setting
mode pressing this key for
2 seconds. will move you
back to the previous
parameter. Pressing this
key for 2 seconds at the
first parameter of the page
will move you back to last parameter of the previous page.
2. The [CAL/VIEW] key.
2a. During any normal mode, pressing this key for about 2 secs
will switch to the first Calibration/Setting screen.
2b. During Calibration/Setting mode this key will switch to the
next available Calibration/Setting page pressing this key at
the last User/Calibration page(TEMP. CONTROL SETTING
page) will return the user to the Normal mode.
3. The [ ] UP key.
During Calibration/Setting mode this key will increment the
current blinking digit of the active parameter.
4. The [ ] DOWN key.
During Calibration/Setting mode this key will decrement the
blinking digit of the active parameter.
MODE CAL.
VIEW
CURSOR
JENCO
6308CT

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5. The [ ] ENTER key.
During Calibration/Setting mode this key will save the
current modified parameter and move to the next parameter
on the page if the parameter is the last one on the page then it
will move to first parameter on the next available page.
6. The [ ] LIGHT key.
This key will turn on or turn off the backlight of the LCD.
The backlight will automatically turn off if there is no key
activity within two minutes.
7. LCD screen.
B. NORMAL MODE DISPLAY
1. CELL or TDS F– Actual
cell constant of the
probe computed from
the last cell constant
calibration. In TDS
display it will show the
TDS factor instead of
the cell constant.
2. CURRENT OUT - this
will display the actual
output of the isolated 4-20 mA output. At POWER-ON this will
show “OFF” for about 3 seconds before going to normal
operation. After going to the Calibration/Setting pages when the
unit is not password locked this will show ”FROZEN” for about
3 seconds before returning to normal operation.
3. ( )key icon annunciator - This will be displayed if the
Calibration /Setting pages are locked, meaning the user will
not be able to change the values unless the correct 4 digit
number has been entered at the PASSWORD CHECK page.
4. H1 or L1 annunciator - this is the status of Conductivity/TDS
1
2
3
4
5
6
7
8
9

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Relay 1, if this is displayed then the relay is ON. (H stands for
high action control and L stands for low action control)
5. H2 or L2 annunciator – this is the status of Conductivity/TDS
Relay 2, if this is displayed then the relay is ON.
6. H3 or L3 annunciator – this is the status of the Temperature
Relay 3, if this is displayed then the Relay is ON.
7. TC- User selected temperature coefficient of the conductivity/
TDS solution.
8. Conductivity or TDS display.
9. Temperature display.
C. REAR CONNECTORS
Before wiring the probes, relays, analog output, RS485 and power
cord be sure that you are connecting to the right terminal as shown
below (be sure the ac-plug is not plugged-in). Remember that the
unit is ON once the user plugs in the power cord to an AC power
supply.

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1. Connect the AC line to the rear of the instrument. The model
6308CT can be used with 115 or 230 VAC 50/60 Hz. Power
consumption is 6 watts. Make sure the EARTH connector is
connected to the earth lead of the AC power line.
2. Connect the proper load to the output relays. Make sure that the
load does not exceed the relay rating, 5 Amp at 115 VAC and 2.5
Amp at 230 VAC.
3. Set the proper load to the 4-20mA output connector. Make sure
that the load impedance is less than 500 Ohms.
4. If the user uses a two-wire conductivity probe, the user needs to
short terminal D1 with terminal S1 and terminal D2 with terminal
S2.
CAUTION: Make sure you connect the AC power cord to the
correct AC terminals. Connecting incorrectly may damage the unit
permanently.
D. TURNING ON/OFF THE INSTRUMENT
By just plugging the unit to a
correct AC voltage the unit will be
ready for use. There is no Power
key so unplugging and plugging
the unit will turn OFF or turn ON
the unit respectively.
After the unit is turned on, it will
perform some basic self diagnostics
and will display “OK” or “BAD”. If
you received any “BAD” messages turn OFF the unit and turn it ON
again.(see VI. ERROR DISPLAYS AND TROUBLESHOOTING ).
If the message persists then you might need to call your distributor.
(See X. WARRANTY).
After the self-diagnostic is complete the temperature will be
displayed on the lowest part of the screen and you are ready to
make conductivity or TDS measurements. Just immerse the probes

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halfway to the liquid. If possible do not allow the probes to touch
any solid object in the solution. There should be no air bubbles
around the probes either. Shaking or moving the probes vigorously
before recording any measurement will dislodge any bubbles
formed in the probes.
PROBE HANDLING AND MAINTENANCE
REMINDER: If the user uses a two-wire conductivity probe, the
user needs to short terminal D1 with terminal S1 and terminal D2
with terminal S2.
Handling the probe
To ensure accurate and repeatable results:
1. The probe (cell) must be clean before making any measurements.
If measuring low conductivity solutions, extra ordinary
cleanliness may be necessary.
2. The probe cell plates must totally submerged in the solution.
The electrode chamber must be free of trapped air or particulates.
You may need to tap the probe gently to dislodge any air bubbles.
3. Ideally, the probe should be at least 1/4 inch away from any
object, including the sides and bottom of the container.
4. Stirring may be necessary for high accuracy readings.
5. If possible, isolate the solution container from ground potentials.
6. Electrical fields and stray currents caused by stirrer motors,
heaters, etc., can interfere with the measurements. The user
should determine the effects of these and make the necessary
corrections either by shielding or by disconnecting those units
that cause trouble.
7.Always rinse the cell carefully before using it in another solution.
8. Never store a dirty or contaminated probe.