ISCO Orbit OCM 223 Operating instructions

Orbit OCM 223 / 253
Transmitter for Free Chlorine/Chlorine Dioxide
Installation and Operation Guide
Isco Part # 69-0043-002
51513336

Foreword
This instruction manual is designed to help you gain a thorough understanding of the
operation of the equipment. Isco recommends that you read this manual completely
before placing the equipment in service.
Although Isco designs reliability into all equipment, there is always the possibility of a
malfunction. This manual may help in diagnosing and repairing the malfunction.
If the problem persists, call or email the Isco Customer Service Department for assis-
tance. Contact information is provided below. Simple difficulties can often be diag-
nosed over the phone. If it is necessary to return the equipment to the factory for
service, please follow the shipping instructions provided by the Customer Service
Department, including the use of the Return Authorization Number specified. Be
sure to include a note describing the malfunction. This will aid in the prompt
repair and return of the equipment.
Isco welcomes suggestions that would improve the information presented in this man-
ual or enhance the operation of the equipment itself.
Isco is continually improving its products and reserves the right to change
product specifications, replacement parts, schematics, and instructions
without notice.
Contact Information
Phone: [phone] (USA, Canada, Mexico)
[phone] (Outside North America)
Repair Service: [phone] (Analytical and Process
Monitoring Instruments)
[phone] (Samplers and Flow Meters)
Fax: [phone]
Email address: [email protected]
Website: www.isco.com
Return equipment to: 4700 Superior Street, Lincoln, NE 68504-1398
Other correspondence: P.O. Box 82531, Lincoln, NE 68501-2531
Revised February 12, 2003

OCM 223 / 253 Table of Contents
3
Table of Contents
Table of Contents . . . . . . . . . . . . . . . . . . . . . . . 3
1 Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1 Safety symbols . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.2 Intended application . . . . . . . . . . . . . . . . . . . . 4
1.3 Installation, start-up, operation . . . . . . . . . . . . 4
1.4 Operational safety . . . . . . . . . . . . . . . . . . . . . . 5
1.5 Return to manufacturer . . . . . . . . . . . . . . . . . . 5
2 Identification . . . . . . . . . . . . . . . . . . . . . . 6
2.1 Equipment name . . . . . . . . . . . . . . . . . . . . . . . 6
2.2 Additional functions of ES and EP versions . . . 7
2.3 Scope of supply . . . . . . . . . . . . . . . . . . . . . . . . 7
3 Installation . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.1 Measuring system . . . . . . . . . . . . . . . . . . . . . . 8
3.2 Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.3 Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
4 Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.1 Electrical connection . . . . . . . . . . . . . . . . . . . 14
4.2 Installing the sensor
and connecting the measuring cable . . . . . . 17
5 Operation . . . . . . . . . . . . . . . . . . . . . . . . . 20
5.1 User interface . . . . . . . . . . . . . . . . . . . . . . . . 20
5.2 Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5.3 Key functions . . . . . . . . . . . . . . . . . . . . . . . . . 21
5.4 Auto / Manual operating modes . . . . . . . . . . 23
5.5 Operating concept . . . . . . . . . . . . . . . . . . . . . 24
5.6 Access codes . . . . . . . . . . . . . . . . . . . . . . . . 26
5.7 Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
5.8 Automatic controller switch-off . . . . . . . . . . . 26
6 Instrument configuration . . . . . . . . . 27
6.1 Start-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
6.2 System configuration . . . . . . . . . . . . . . . . . . . 29
6.3 Current input . . . . . . . . . . . . . . . . . . . . . . . . . 35
6.4 Current outputs . . . . . . . . . . . . . . . . . . . . . . . 38
6.5 Monitoring functions . . . . . . . . . . . . . . . . . . . 41
6.6 Relay contact configuration . . . . . . . . . . . . . . 45
6.7 Service 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
6.8 Service 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
6.9 Interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
6.10 Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
7 Diagnosis and corrective
maintenance . . . . . . . . . . . . . . . . . . . . . . 65
7.1 Troubleshooting and remedial action
based on common problems . . . . . . . . . . . . . 65
7.2 Troubleshooting based on error messages . . 68
8 Diagnosis and corrective
maintenance . . . . . . . . . . . . . . . . . . . . . . 71
8.1 Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
8.2 Corrective maintenance of OCM 223 . . . . . . . 74
8.3 Corrective maintenance of OCM 253 . . . . . . . 76
8.4 Ordering spare parts . . . . . . . . . . . . . . . . . . . 79
8.5 “Optoscope” service equipment
with “Scopeware” . . . . . . . . . . . . . . . . . . . . . . 79
8.6 Corrective maintenance of the
complete measuring point . . . . . . . . . . . . . . . 79
8.7 Test and simulation . . . . . . . . . . . . . . . . . . . . . 81
9 Accessories . . . . . . . . . . . . . . . . . . . . . . . 83
9.1 Connection accessories . . . . . . . . . . . . . . . . . 83
9.2 Mounting accessories . . . . . . . . . . . . . . . . . . . 83
9.3 Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
9.4 Calibration accessories . . . . . . . . . . . . . . . . . 84
9.5 Instrument upgrade . . . . . . . . . . . . . . . . . . . . 85
10 Technical data . . . . . . . . . . . . . . . . . . . . 86
11 Annex . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
11.1 Operating matrix of EK and ES versions . . . . 90
11.2 Operating matrix of EP version . . . . . . . . . . . . 94
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100

1 Safety OCM 223 / 253
4
1 Safety
1.1 Safety symbols
#Warning!
This symbol alerts you to hazards which could cause serious injuries as well as damage
to the instrument if ignored.
"Caution!
This symbol alerts you to possible faults which could arise from incorrect operation.
They could cause damage to the instrument if ignored.
!Note!
This symbol indicates important items of information.
1.2 Intended application
OCM 223 / 253 is a field-tested and reliable transmitter which determines the amount of
free chlorine or chlorine dioxide dissolved in water.
It is specially designed for applications in the following industries:
xDrinking water
xWater treatment
xCooling water
xGas scrubbers
xReverse osmosis
xFood processing
xSwimming pool and bathing pool water.
1.3 Installation, start-up, operation
#Warning!
xInstallation, electrical connection, start-up, operation and maintenance of the
measuring instrument must be carried out exclusively by trained specialists
authorised by the system operator.
xThis personnel must have read and understood the instructions in this manual and
must adhere to them.
xBefore connecting the instrument ensure that the power supply complies with the
ratings specified on the nameplate.
xA clearly marked mains disconnecting device must be installed in the vicinity of the
instrument.
xLive components in the interior of the instrument can be touched through the
ventilation slits and the slit openings on the instrument back. Do not insert any tools
or wires into these slits (only OCM 223)!
xBefore switching on the system check all the connections again for correctness.
xDo not operate damaged instruments which could pose a danger, and mark them as
defective.
xMeasuring point faults may only be repaired by authorised and trained personnel.
xIf faults cannot be repaired, the instrument must be taken out of service and secured
against unintentional start-up.
xRepairs may only be carried out by the manufacturer or by your Service Organisation.

OCM 223 / 253 1 Safety
5
1.4 Operational safety
The instrument has been designed according to the state of the art and complies with
the applicable regulations and EN standards (see “Technical Data”). It is built in
accordance with EN 61010-1 and left our factory in perfect condition with regard to
safety aspects.
However, if it is used improperly or other than for its intended purpose, it may pose a
hazard, e.g. due to improper connection.
#Warning!
xIf the device is used for any application other than those described in this manual, it
may lead to unsafe and improper functioning of the measuring system and is therefore
strictly prohibited.
xMake sure you strictly adhere to the safety instructions and warnings in this manual.
Monitoring and safety devices
The instrument is protected against external influences and damage by the following
design measures:
xRugged housing
xHousing protection IP 65 (OCM 253)
xUV resistance.
If system faults or a power failure occur, an alarm is triggered by a fault-signalling
contact.
Fail-safety
This instrument has been tested for electromagnetic compatibility in industrial use
according to applicable European standards. It is protected against electromagnetic
interference by the following design measures:
xGalvanic isolation at input and output
xInterference suppression filter
xHardware and software design meeting EMC requirements.
#Warning!
Protection against interference as specified above is valid only for an instrument
connected according to the instructions in this manual.
1.5 Return to manufacturer
If the instrument has to be repaired by the manufacturer, please return it cleaned to the
sales centre responsible. Please use the original packaging.

2 Identification OCM 223 / 253
6
2 Identification
2.1 Equipment name
2.1.1 Nameplate
Fig. 2.1: Nameplate of OCM 223 (panel-mounted instrument, left) and
OCM 253 (field instrument, right).
“Codes” lists the release code for software upgrades for ChemoClean (left of slash)
or Plus package (right of slash).
2.1.2 Product structure
Version
EK Measurement of free chlorine / chlorine dioxide
ES Measurement of free chlorine / chlorine dioxide with extended features
EP Measurement of free chlorine / chlorine dioxide with extended features,
in addition pH or redox measurement (switchable)
Power supply
0 Power supply 230 V AC
1 Power supply 115 V AC
2 Power supply 230 V AC, CSA Gen. Purp.
3 Power supply 115 V AC, CSA Gen. Purp.
5 Power supply 100 V AC
7 Power supply 24 V AC/DC, CSA Gen. Purp.
8 Power supply 24 V AC/DC
Measurement output
0 1 output signal: Chlorine / chlorine dioxide
1 2 output signals : Chlorine / chlorine dioxide and temperature / chlorine (with
EP version optionally pH / redox / chlorine) or chlorine dioxide / set value
Contacts
05 No additional contacts
10 2 contacts (limit / P(ID) / timer)
15 4 contacts (limit / P(ID) / ChemoClean / three-point step controller for
Cl2/ClO2)
16 4 contacts (limit / P(ID) / timer / three-point step controller for Cl2/ClO2)
20 2 contacts with current input (limit / P(ID) / timer)
25 4 contacts with cleaning, current input (limit / P(ID) / ChemoClean /
three-point step controller for Cl2/ClO2)
26 4 contacts with timer, current input (limit / P(ID) / timer / three-point step
controller for Cl2/ClO2)
OCM 223-
OCM 253-
complete order code
131085-4D
OCM 223
order code
serial no. /
codes
chlorine / chlorine dioxide
OCM 223-EK0110
276945
0.05 … 20 mg/l
0 … 50°C
0/4 … 20 mA
230 VAC 50/60 Hz 7.5 VA
-10 … +55°CIP 54 / IP 30
0/4…20mA
-8732
prot. class ambient temp.
output 1 output 2
mains
meas. range
temperature
3472
131085-4D
OCM 253
order code
serial no. /
codes
chlorine / chlorine dioxide
OCM 253-EK0110
276944
0.05 … 20 mg/l
0…50°C
0/4…20mA
230 VAC 50/60 Hz 7.5 VA
-10 … +55°CIP 65
0/4…20mA
-8732
prot. class ambient temp.
output 1 output 2
mains
meas. range
temperature
3472

OCM 223 / 253 2 Identification
7
2.2 Additional functions of ES and EP versions
ES version
Compared to the basic EK version, this version is extended by the Plus package:
xManual pH compensation for free chlorine, fields B2 and B3
xCurrent output table, fields O33x
xSensor and process monitoring, function group P
xAutomatic start of cleaning function, field F8.
EP version
This version includes the functions of the ES version and in addition:
xOptional pH or redox measurement, field B1
xAutomatic pH compensation for free chlorine
xSensor and process monitoring even for pH or redox, fields P12x
xLimit contact for pH or redox, fields R22x
xpH value control, fields R25x.
2.3 Scope of supply
"Caution!
xMake sure the packaging is undamaged! If any damage is found, contact your postal
service or forwarding agent. Keep any damaged packaging until matters have been
clarified.
xMake sure the contents are undamaged! If any damage is found, contact your postal
service or forwarding agent and inform the suppliers. Keep any damaged goods until
matters have been clarified.
xInspect the delivery for completeness and quantity according to the delivery papers,
and the instrument type and version as shown on the nameplate.
The following items are included in the delivery:
xTransmitter OCM 223 (panel-mounted instrument) or OCM 253 (field instrument)
xOperating instructions BA 214e00
xPanel-mounted instrument:
– 1 set of plug-in screw terminals
– 2 clamping screws for panel mounting
additional for EP version:
– 1 BNC connector (solderless)
xField instrument:
– 1 plug-in screw terminal
– 1 × cable gland Pg 7
– 1 × cable gland Pg 16, tapered
– 2 × cable gland Pg 13.5.
In case of any queries please contact your supplier or your Sales Agency.

3 Installation OCM 223 / 253
8
3 Installation
The following procedure should be followed for a complete measuring system
installation:
1. Installation or attachment of transmitter (see chapter 3.3)
2. Selection and connection of cables and sensor (see chapter 4.2)
3. Start-up (see chapter 6.1).
3.1 Measuring system
A complete measuring system comprises:
xthe OCM 223 or OCM 253 chlorine / chlorine dioxide transmitter
xa OCS 140 / 141 membrane-covered sensor for Cl2or OCS 240 / 241 for ClO2or
a 963 open sensor for Cl2
xa OCA 250 flow assembly (not required for 963 sensor).
Options:
xpH or redox electrode (e.g. OPS 31, OPS 12, OPS 32)
xINS proximity switch for flow monitoring (omitted with 963 sensor)
xOMK extension cable for chlorine measurement
xOYK 71 extension cable for pH/redox measurement if required
xMK extension cable for INS proximity switch
xVBC junction box.
Fig. 3.1: Complete measuring system with OCM 253
CAL REL
REL 1
REL 1
ALARM
REL 2
REL 2
E
mg/l
25.0 °C
0.42
Transmitter
OCM 253
Chlorine or
chlorine dioxide
sensor
Mounting points for pH
or redox electrode
Inductive proximity
switch for flow
monitoring
Flow plummet
Meas. water feed
(sample flow)
Meas. water
drain
Flow assembly
OCA 250
Main stream
Sampling valve for
DPD measurement
Screw and
calibration cap
B214C03E.eps
VBC junction box (only if
connection length > standard length)

OCM 223 / 253 3 Installation
9
3.2 Dimensions
Fig. 3.2: Dimensions of OCM 253
!Note!
There is a hole in the punching for Pg 16 cable entry. Itr serves as a pressure balance
during air freight dispatching. Make sure that there is no moisture penetrating into the
housing before cable installation. After cable installation the housing is completely tight.
Fig. 3.3: Interior view of OCM 253 housing
1 Removable electronics box; 2 Partition plate; 3 Terminal blocks; 4 Fuse
B214C04Y.eps
CAL REL
REL 1
REL 1
ALARM
REL 2
REL 2
E
11
Pg13,5
Pg 7
Pg 16
115 70
154
247
157
70
170
B214C05E.eps
Æ6.5

3 Installation OCM 223 / 253
10
Fig. 3.4: Dimensions of OCM 223
3.3 Mounting
3.3.1 Field instrument
There are several mounting options for the field instrument version of the transmitter:
xMounting on round posts
xMounting on square posts
xWall mounting.
When installing the instrument outdoors, you require weather protection cover OYY 101
for all mounting options.
"Caution!
In case of direct exposition to weather factors, the weather protection cover is
indispensable.
Weather protection cover OYY 101
Weather protection cover for outdoor operation, for mounting on field instrument;
Material: stainless steel 1.4301 (AISI 304).
For post or pipe mounting, the post mounting kit is additionally required.
B214C07Y.eps
90 6
139
96
B214C08Y.eps

OCM 223 / 253 3 Installation
11
Fig. 3.5: Weather protection cover for field instruments
Post mounting kit
Mounting kit for mounting the field housing on horizontal and vertical pipes
(max. 60 mm); is also used for attachment of the weather protection cover.
Material: stainless steel 1.4301 (AISI 304)
Universal mounting post OYY 102
Square pipe for mounting transmitters; Material: stainless steel 1.4301 (AISI 304)
Fig. 3.6: Mounting kit for mounting on round posts (left)
Square mounting post (right)

3 Installation OCM 223 / 253
12
3.3.2 Mounting examples
Fig. 3.7: Field instrument: pipe mounting
Fig. 3.8: Field instrument:
Wall mounting (left), mounting with universal mounting post and weather protection cover (right)
B214C12Y.eps

OCM 223 / 253 3 Installation
13
3.3.3 Panel-mounted instrument
The instrument is attached using the supplied clamping screws (see Fig. 3.9). The total
installation depth required is approx. 165 mm.
Fig. 3.9: Attachment of panel-mounted instrument
1 Wall of control cabinet
2 Seal
3 Clamping screws

4 Wiring OCM 223 / 253
14
4 Wiring
4.1 Electrical connection
4.1.1 Terminal diagram
The terminal diagram depicted in Fig. 4.1 shows the connections for the
membrane-covered OCS 140 / 141 / 240 / 241 sensor or the open 963 sensor.
Fig. 4.1: Electrical connection of OCM 223 / 253 (full wiring)
47
48
49
57
58
59
41
42
43
15 V
85
86
81
93
82
94
mA
31
32
mA
mA
33
34
51
52
53
54
55
56
23
24
90
12
11
91
92
S
ClO
2
ClO
2
Cl
2
Cl
2
K
A
A
K
K
A
NTC
pH
Red.
Ref.
PA/
PM
10–50 V**
*Contact position depicted:
de-energised or error
**Auxiliary output voltage
term. 85/86 can be used
B214C16E.eps
bn
bl
rd
bl
bn
gn
Relay 2*
pH/
Redox
optional
optional
Sensor
OCS 140 / 141
OCS 240 / 241
Alarm*
Relay 1*
Relay 3*
Relay 4*
Current input
4 ... 20 mA
Power supply
alternative
Sensor 963
Proximity
switch INS
Digital
input 2
Signal output 1:
Chlorine or
chlorine dioxide
Signal output 2:
Temperature,
pH or redox
(optional)
Aux. voltage
output
bk
Digital input 1
(hold / cleaning) With Chemoclean:
Cleaner
With Chemoclean:
Water
rd
L+
L–N
L1
~ =

OCM 223 / 253 4 Wiring
15
!Note!
The instrument has protection class II and is usually operated without protective earth
connection.
Connecting the chlorine sensor 963
The chlorine sensor 963 is delivered from the factory without an integrated temperature
sensor for measuring the temperature. Therefore connect the temperature input
(terminals 11/12) as follows:
xNo temperature measurement required:
Connect supplied equivalent resistor 10 k:(Part No. 50061891). The display reading
then shows a constant 25 °C.
xTemperature measurement required:
Screw in NTC temperature sensor 10 k:/ 25 °C, 120 mm mounting version
(TSP 3692) in the chlorine sensor 963 and connect using connecting cable OPK 1.
Connecting the pH or redox electrode
pH or redox electrodes can be connected either symmetrically or asymmetrically.
However, the OCM 223 / 253 is always connected symmetrically to prevent a mutual
interference of several sensors mounted in the OCA 250 assembly. Do not connect
asymmetrically!
Symmetrical connection requires an potential matching pin. It is integrated as standard
in the OCA 250 flow assembly and is connected to the PA/PM terminal by a potential
matching line.
!Note!
When the pH or redox electrode is calibrated outside the OCA 250 assembly, remove
the potential matching line from the assembly, extend it if required and immerse it in the
buffer solution.
Three-point step controller for Cl2/ClO2
Use the following arrangement for activating continuously variable motor valves:
xRelay 3: Connect to the NO contact of the motor valve
xRelay 4: Connect to the NC contact of the motor valve.
Use of the digital inputs
xDigital input 1 operates as hold input. On the ES / EP versions, it is switchable as
cleaning trigger input.
xDigital input 2 is used for flow monitoring in the OCA 250 assembly. This requires an
inductive proximity switch INS. Flow monitoring can be switched on or off by an
operating function.
Use of the current input
The current input has two independent usabilities (see chapter 6.3):
xMonitoring the flow rate in the main stream
xFeedforward control to PID controller.

4 Wiring OCM 223 / 253
16
4.1.2 Terminals on field instrument
Insert the measuring cable through the cable glands of the field instrument and connect
the wires as shows in the terminal diagram in Fig. 4.1 and 4.2.
Fig. 4.2: Connection compartment sticker for OCM 253 field instruments
4.1.3 Terminals on panel-mounted instrument
Fig. 4.3: Connection compartment stickers for OCM 223 panel-mounted instruments
pH / Redox 42
++ ++++-
-
----
434154 55 56
NC
91
90
31
11
12
32
92
PA/PM
3433
S
REF
NC 938685 94 81 23 82 24 NC
51 52 53 57 58 59 47 48 49
Cl
ClO2
(963:92/K)
2
Temp.
pH/Redox
(opt.)
+15V
10mA
BN
(RD)GN(BU)
BN
REL 4SENSOR REL 3 REL 2 REL 1
131194-4D
OCM 253
Digital 2
(INS)
Digital 1
4..20mA
1191/A
1290/K
NC
Mains
Hilfsenergie
L1
+
N
-
(AC)
(DC)
Contacts:
max. 2A
AC: 250V/500VA
DC: 30V/60W
B214C17Y.eps
B214C19Y.eps
REL1
REL2
REL3
REL4
4..20mA
24
23
49
COM
COM
COM
COM
-
+
59
54
55
56
52
51
53
58
57
48
47
131084-4C
31 +
32 -
33 +
PA/PM
34 -
85 +
NC
91
90
NC
(REF)
Sensor
NC
86 -
93 + S
94 - 42
81 + 43
82 - 41
Cl2
Temp.
pH
Redox
(opt.)
+15V
10mA
Digital 2
(INS)
Digital 1
92
12
11
K
A
BN
BN
GN
131192-4C
K
ClO2
963
CCS..
963
BNC: pH/Redox + REF
RD
BU
Mains Contacts: max. 2A, AC:250V/500VA, DC:30V/60W
L1 +
AC DC
N-

OCM 223 / 253 4 Wiring
17
4.2 Installing the sensor and connecting the
measuring cable
4.2.1 Connecting the measuring cable
The OCS 140 / 141 / 240 / 241 chlorine / chlorine dioxide sensors are equipped with
3 m fixed cable and can be connected to the transmitter. Connecting cables are
required for the open chlorine sensor 963 and for the pH or redox electrode in the case
of the EP instrument version. A VBC junction box and the associated extension cable
(see chapter 9) must be used to extend the measuring cable.
4.2.2 Make-up and termination of the measuring cable
Factory termination of the sensor cable
Fig. 4.4: Terminal cable end of sensors OCS 140 / 141 / 240 / 241
Fig. 4.5: Connection of sensor 963
Required special measuring cable for connecting sensors
Sensor type Cable Extension
Chlorine / chlorine dioxide
sensors OCS140/141/240/241
3mOMK
permanently connected VBC box + OMK
Chlorine sensor 963 – (luster terminal) VBC box + MK
pH or redox electrode
without temperature sensor
OPK 1 for electrodes with
GSA plug-in head
OPK 9 for electrodes with
ESA plug-in head
VBC box + OYK 71
Maximum cable length
Chlorine / chlorine dioxide max. 30 m with cable OMK / MK
pH/redox measurement max. 50 m with cable OYK 71

4 Wiring OCM 223 / 253
18
Fig. 4.6: Make-up of special measuring cable OPK 1 (above) and OPK 9 (below)
Cable termination for panel-mounted OCM 223 with solder-free BNC connector
Fig. 4.7: Cutting off the cable end (left) and make-up of inner coaxial cable (right)
Fig. 4.8: Termination of pH terminal wire for mounting the BNC angular connector (left)
Mounting the pH terminal wire in the BNC angular connector (right)

OCM 223 / 253 4 Wiring
19
1. Cut off terminated end of the inner coaxial cable (see Fig. 4.7).
2. Push cable gland (➀) and disc (➁) onto coaxial cable, strip outer insulation (13 mm),
then screw clamping ring (➂) onto insulation.
Note: Parts ➀to ➂are supplied for cable diameters of 3.2 mm and 5 mm. For CPK 1,
CPK 9 and CYK 71, a diameter of 3.2 mm is required.
3. Mould screen wire braid (➃) over clamping ring and cut off projecting ends.
4. Remove black semiconductor layer up to screen (reference signal).
5. Remove inner insulation (4 mm). Attach supplied wire end ferrule (➈) onto inner
conductor. If you use a non-supplied cable, then a wire end ferrule is only required
with wire strands.
6. Push BNC connector receptacle (➄) over cable (inner conductor or end sleeve must
be in the clamping notch (➅) of the connector pin). Tighten cable gland (➀). Clamp
the inner conductor tightly to the clamping notch by inserting the clamping piece (➆)
and tightening the connector cover (➇). This produces the contact.
VBC junction box
!Note!
The maximum connecting cable length between the sensor and the instrument is 30 m.
Fig. 4.9: VBC junction box, with earthing point; size: 125 × 80 × 54 mm (w × h × d)
Cable termination of OMK and OYK 71 extension cables
Fig. 4.10: Make-up of OMK (for sensors OCS x4x, left) and OYK 71 (for pH/redox, right) cables
"Caution!
Do not forget to remove the black semiconductor layer (➀) up to the inner screen when
performing termination work!

5Operation OCM 223 / 253
20
5Operation
5.1 User interface
Fig. 5.1: Operating elements
5.2 Display
5.2.1 LED indicators
Display of current operating mode: auto (green LED) or manual (yellow LED)
Display of triggered relay in manual mode (red LED)
Display of operating state of relays 1 and 2
Green LED: Relay inactive
Red LED: Relay active
Alarm display, e.g. on upper limit violation, failure of temperature sensor or
system fault (see Fault Diagnosis Chart in chapter 7.2)
0.42 mg/l
R242
Setpoint
Liquid crystal display
for measured and
configuration data
Field for user labelling
4 main control keys
for calibration and
instrument configuration Toggle key for
Auto/Manual mode
Indicates active
contact and key for
toggling relay
to Manual mode
Indicator LED for
alarm function
Indicator LEDs for
limit contactor
relay
(switch state)
B214C31E.eps