Endress+Hauser liquisys CPM 252 User manual

BA 169C/07/en/04.98
No. 50087273
Software version 1.01 or later
liquisys
CPM 252
Transmitter/Controller
for pH and Redox
Operating Instructions
Hauser+Endress
Nothing beats know-how

Please familiarise yourself with the instrument before you
take any other steps:
General information
Safety
Description
You wish to install and start up the instrument. The
required steps are described in these chapters:
Installation
First start-up
You wish to operate or reconfigure the instrument. The
operating concept is explained in these chapters:
Operation
Instrument configuration
See the back cover for a fold-out overview of the menu
structure.
When you encounter problems or when the instrument
requires maintenance, refer to these chapters for help:
Diagnostics
Maintenance and service

Table of contents
1 General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1 Symbols used ............................................2
1.2 Conformity statement ........................................2
2 Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.1 Intended use .............................................3
2.2 General safety notes .........................................3
2.3 Safety devices ............................................3
3 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3.1 Areas of application .........................................4
3.2 Measuring system ..........................................4
3.3 Important features ..........................................5
3.4 Instrument variants ..........................................6
3.5 Accessories .............................................7
4 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4.1 Storage and transport ........................................9
4.2 Unpacking ..............................................9
4.3 Mounting.............................................. 10
4.4 Connection............................................. 12
4.5 Packaging and disposal ...................................... 17
5 First start-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
5.1 Measures before first power-up .................................. 18
5.2 Power-up, factory settings ..................................... 19
5.3 First configuration and calibration ................................. 20
5.4 Test ................................................ 20
6 Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
6.1 Operator interface ......................................... 21
6.2 Display elements .......................................... 21
6.3 Keyfunctions ........................................... 23
6.4 Operating concept ......................................... 24
6.5 Operation example ........................................ 26
6.6 Auto / manual mode of operation ................................. 28
7 Instrument configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
7.1 Offset adjustment ......................................... 30
7.2 Selection of temperature compensation ............................. 31
7.3 Limit contactor configuration , ................................... 32
7.4 Controller configuration ...................................... 33
7.5 Current output measuring range selection ............................ 36
7.6 General instrument configuration ................................. 37
7.7 Calibration of measuring transmitter ............................... 38
8 Diagnostics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
8.1 Alarm................................................ 42
8.2 Errors ................................................ 42
8.3 Possible faults in measuring mode and elimination ........................ 44
9 Maintenance and service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
9.1 Cleaning.............................................. 46
9.2 Repair ............................................... 46
10 Appendix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
10.1 Technical data ........................................... 47
10.2 Index ................................................ 50
liquisys CPM 252 Table of contents
Endress+Hauser 1

1 General information
1.1 Symbols used
Warning:
This symbol alerts to hazards which may cause serious injuries as well as damage to
the instrument, measuring system or other equipment if ignored.
Caution:
This symbol alerts to possible malfunction due to operator error.
Note:
This symbol indicates important items of information.
1.2 Conformity statement
The pH and redox measuring instrument / controller Liquisys CPM 252 has been developed and
manufactured in accordance with the applicable European standards and directives.
Note:
The corresponding certificate of conformity may be requested from Endress+Hauser.
General information liquisys CPM 252
2 Endress+Hauser

2 Safety
2.1 Intended use
The measuring transmitter Liquisys CPM 252 is a field-tested and reliable measurement and
control device for determining pH values and redox potentials. It is equipped with two current
outputs and two switched outputs for connection to automated process controllers.
2.2 General safety notes
Warning:
●Operation of the device in a manner other than as described in these operating
instructions may lead to unsafe and improper functioning of the measuring system.
Installation, start-up, operation
The Liquisys CPM 252 instrument has been designed for safe operation according to the state
of the art in engineering and in keeping with the applicable regulations and EC directives; see
“Technical data”. However, if used improperly or other than for the intended purpose, it may
pose a hazard, e.g. due to improper connection.
Installation, electrical connection, start-up, operation and maintenance of the measuring system
must therefore be performed exclusively by trained specialists authorised by the system
operator. This personnel must have read and understood these operating instructions and must
adhere to them.
2.3 Safety devices
●Access code:
Unauthorised access to the calibration and configuration data of the measuring transmitter is
effectively prevented by access codes. The instrument settings can be read at any time
without entry of an access code.
●Alarm function:
Continuous violation of the limit settings or temperature sensor failure will activate an alarm.
This condition is indicated by an LED on the control panel and via a switched output. The
alarm contact has been designed as a fail-safe switch, i.e. the alarm condition will be
immediately signalled in case of a power failure. The alarm contact is also activated by
internal system errors (see 8.2).
●Data protection:
The instrument configuration is retained even after a power failure.
●Immunity to interference:
This instrument is protected against interference, such as pulse-shaped transients, high
frequency and electrostatic discharges, according to the applicable European standards.
This is only valid, however, for an instrument connected according to the notes in these
installation and operating instructions.
liquisys CPM 252 Safety
Endress+Hauser 3

3 Description
3.1 Areas of application
The measuring transmitter Liquisys CPM 252 is suitable for measuring and control tasks in the
following areas of application:
●Water treatment and water monitoring
●Effluent treatment
●Neutralisation
●Detoxification in the electroplating industry
3.2 Measuring system
pm252sys.cdr
Immersion
assembly
CPA 111
Process
assembly
CPA 440
Electrode
e.g. Orbisint CPS 11
with integr. Pt 100
Flow assembly
CPA 250
Junction
box VBA
Liquisys CPM 252
Measuring
cable
e.g. CPK 7
2 limit contacts
(i, f, s/w control)
1 alarm contact
Current output 1: pH / mV
0/4 ... 20 mA
15 V supply voltage
HOLD
Auxiliary energy (mains)
Current output 2: temp.*
0/4 ... 20 mA
* optional
Fig. 3.1 Example of a complete measuring system
Description liquisys CPM 252
4 Endress+Hauser

A typical measuring system comprises:
●a pH combination electrode with or without integrated temperature sensor Pt 100 or a redox
combination electrode
●an additional temperature sensor Pt 100 if used with electrodes without an integrated
temperature sensor
●an appropriate immersion, flow or retractable assembly with or without potential matching pin
●an appropriate pH or redox measuring cable
●the Liquisys CPM 252 measuring transmitter
3.3 Important features
●Field housing with protection type IP 65
●Measuring range pH 0 ... 14 / ±1000 mV
●Switching between pH and redox potential measurements
●Temperature measurement -9.9 ... +125 °C
●Easy to read, two-line display
●Simple configuration with only three keys
●Configuration protected by access code
●Quick calibration using the “CAL”key
●Two switched outputs which can be configured as a pulse length controller, pulse frequency
controller or limit contactor
●One switched output for alarm signalling in cases of limit violation or temperature sensor
failure
●Two current outputs with selectable measurement range, switchable between 0 ... 20 or
4 ... 20 mA (switching affects both outputs)
●Automatic “hold”function to “freeze”the current output and switched outputs during calibrati-
on and configuration
●“Hold”function via a galvanically separated input, can be controlled using an external or
internal auxiliary voltage
liquisys CPM 252 Description
Endress+Hauser 5

3.4 Instrument variants
You can identify the device variant and the
mains supply type by the order code on the
nameplate of the instrument.
Composition of order code
Version / measuring range
PR Field housing, 247 x 170 x 115 mm, protection type IP 65
Switchable to pH or redox measurement
Power supply
0 Power supply: 230 V AC
1 Power supply: 115 V AC
2 Power supply: 200 V AC
3 Power supply: 24 V AC
5 Power supply: 100 V AC
8 Power supply: 24 V DC
9 Special version to customer specifications
Measurement output
0 Meas. output: pH/redox
1 Meas. output: pH/redox and temperature
9 Special version to customer specifications
Additional features
10 Base version
20 Moisture protection lacquering
CPM 252- ⇐complete order code
typ252ph.cdr
Fig. 3.2 Nameplate of Liquisys CPM 252
Description liquisys CPM 252
6 Endress+Hauser

3.5 Accessories
Endress+Hauser offer a wide selection of matching electrodes and assemblies for the Liquisys
measuring instrument which are designed for special applications. An overview of these ap-
pears below.
Electrodes
Please refer to the electrode catalogue (order no. 50071679) for further information on electro-
des and measuring cables.
Type Features Areas of application
Orbisint
CPS 11/12/13
Universally applicable, easily cleanable and
soiling-resistant thanks to PTFE diaphragm,
pressures of up to 6 bar,
conductivity > 50 µS/cm
General process
engineering
Industrial waste water
Detoxification
(cyanogen, chromium)
Neutralisation
Ceratex
CPS 31/32/33
Inexpensive electrodes with ceramic
diaphragm, long life
Drinking water
Swimming pools
Ceraliquid
CPS 41/42/43
Electrodes with ceramic diaphragm and KCl
liquid electrolyte, for use with counterpressure,
resistant to pressures of up to 8 bar
Ultrapure water
Boiler feed water
liquisys CPM 252 Description
Endress+Hauser 7

Assemblies
Buffer solutions
Type Features Areas of application
Dipsys
CPA 111
Immersion assembly with DN 100 flange,
bayonet mounting for fast electrode installation
and removal, integration of Chemoclean
electrode cleaning system is possible without
modification
Open and closed
containers and tanks
Channels
Probfit
CPA 440 Process assembly for one pH/redox electrode, usable with pressures of up to 6 bar
Pipelines
Containers and tanks
CPA 250-A Flow assembly for up to three electrodes,
syphon-type design keeps sensors wet even if
there is no flow through pipeline
Pipelines
Type Features / contents Areas of application
CPY 2
pH 4.0 red, contents: 100 ml
(order no. CPY 2 - 0)
pH 7.0 green, contents: 100 ml
(order no. CPY 2 - 2)
pH calibration (reference
temperature 25 °C)
CPY 3
+225 mV, pH 7.0, contents: 100 ml
(order no. CPY 3 - 0)
+475 mV, pH 0.0, contents: 100 ml
(order no. CPY 3 - 1)
Redox calibration
(measured at 25 °C with
PtAg or AgCl measuring
chain)
Description liquisys CPM 252
8 Endress+Hauser

4 Installation
4.1 Storage and transport
The packaging material used to store or transport the instrument must provide shock and
moisture protection. Optimal protection is provided by the original packaging materials.
Conformance with the ambient conditions (see Technical data) must be assured.
4.2 Unpacking
Verify that the contents are undamaged. Inform the post office or freight carrier as well as the
supplier of any damage.
Check that the delivery is complete and agrees with the shipping documents and your order:
●Quantity delivered
●Instrument type and version according to the nameplate (see chapter 3.4)
●Accessories
●Operating instructions
Included in delivery:
●1 connector set
●1 x cable gland Pg 7
●1 x cable gland Pg 16, reduced
●2 x cable gland Pg 13.5
The post mounting kit is not included in the delivery.
Save the original packaging in case the device must be stored or shipped at a later time.
If you have any questions, please consult your supplier or the Endress+Hauser sales office in
your area (see back cover of these operating instructions for addresses).
liquisys CPM 252 Installation
Endress+Hauser 9

4.3 Mounting
Wall mounting of Liquisys CPM 252 in field housing
Post mounting of Liquisys CPM 252 in field housing
Additional requirements: post mounting kit (see Mounting accessories). Install the post mounting
kit on the rear of the instrument. Installation is possible on horizontal or vertical piping. The
maximum pipe diameter is 60 mm (see figure 4.2).
pm252wan.cdr
115
157
154
170
247
∅8
Mounting screw: ∅6mm
Anchor: ∅8mm
16
Fig. 4.1 Wall mounting of Liquisys CPM 252
pm252mas.cdr
Fig. 4.2 Post mounting of Liquisys CPM 252
Installation liquisys CPM 252
10 Endress+Hauser

Caution:
Weather protection cover CYY 101 (see Mounting accessories) is to be used for
outdoor installation. The protection cover is suitable for wall or post mounting.
Mounting accessories
Weather protection cover CYY 101
Weather protection cover for outdoor use of
instrument, to be installed on field housing.
Dimensions: 320 x 300 x 270 mm (H x W x D)
Material: special steel
Order no.: CYY101-A
Post mounting kit
Kit for installation of field housing on horizontal
or vertical pipes (max. ∅60 mm)
Material: galvanised steel
Order no. 50086842
300
270
yh-101-6.cdr
320
Fig. 4.3 Weather protection cover CYY 101
pm252mbe.cdr
90
70
66
70
55
∅8
30
90
∅6
90
70
∅8
M5 x 12
M6
Fig. 4.4 Post mounting kit
liquisys CPM 252 Installation
Endress+Hauser 11

4.4 Connection
Warning:
●The connection to the mains may only be established by properly trained specialist
personnel.
●Do not perform service work on the instrument while the instrument is energised.
●The instrument must be grounded before start-up!
●A clearly identified mains disconnecting device must be installed close to the
instrument.
●Before connecting the instrument to the mains, make sure the mains voltage
matches the voltage rating on the nameplate.
Instrument connections
anph252.cdr
Fig. 4.5 Position and designations of the connections on the rear of the instrument; up: rear; left: instrument
with one output; right: instrument with two outputs
Installation liquisys CPM 252
12 Endress+Hauser

Connection diagram
Caution:
Do not connect the two signal outputs with each other! If you want to connect them
both to a PLC with common ground of all inputs, then you must anew isolate one
output galvanically.
pH/mV
15 V
pH
Ref.
81
82
85
86
13
12
11
49
48
47
59
58
57
43
42
41
L+
L-
L
N
∼=
PA/
PM
S
S
S
pH/mV
mA
32
31
mA
34
33
pm252an3.cdr
pH / redox
signal input
Potential matching
Pt 100
*) Contact
status
shown:
no current,
fault present
Hold
input
Signal output 1
pH / redox
Auxiliary
supply
voltage
Power
supply
Relay 1
Relay 2
Alarm
*)
Signal output 2
Temperature
10-50 V
Fig. 4.6 Electrical connection of Liquisys CPM 252
liquisys CPM 252 Installation
Endress+Hauser 13

Connection of pH and redox electrodes
Special pre-assembled and shielded multi-core measuring cables of types CPK 1 to CPK 7 (see
section “Special pH / redox measuring cables”) are used to connect pH and redox electrodes.
Should it become necessary to extend the measuring cables, use junction box VBA and
measuring cable types PMK or CYK 71 (not assembled; see Connection accessories).
Instructions for preparing the measuring cables are included with the cables.
Warning:
Connectors and terminals must be protected against humidity, otherwise faulty
measurements will result!
Choice: Symmetrical or asymmetrical?
The pH and redox electrodes can be connected in either a high-impedance symmetrical or
asymmetrical configuration. General rule:
●No potential matching connector present –asymmetrical connection (see figure 4.7).
●Potential matching connector present –symmetrical connection (see figure 4.8).
However, which arrangement to use may also depend on operating conditions.
Caution:
The instrument is pre-configured for symmetrical measurement. If required, it must be
adapted for asymmetrical connection as described in chapter 7.6.
The conductor for the potential matching pin must be connected to the ”PA/PM”
terminal of the instrument for the symmetrical high-impedance connection.
E
pm252au.cdr
Measuring cable
CPK 7
Potential matching pin (PM/PMC) may be connected (if present)
gn br wt ye
br
11 12 13 Ref
pH/
mV
PA/
PM
ϑpH
Fig. 4.7 Asymmetrical high-impedance
pH electrode connection
E
pm252as.cdr
Measuring cable
CPK 7
(PM/PMC)
PA/
PM
ϑpH
pH/
mV
11 12 13 Ref
ye wt gn br
br
Fig. 4.8 Symmetrical high-impedance pH
electrode connection
Installation liquisys CPM 252
14 Endress+Hauser

Special pH / redox measuring cables
Type: Coaxial cable with auxiliary core and additional outer screen, in PVC sheath,
∅7.2 mm; extension: CYK 71, order no. 50085333
Type: Coaxial cable with 6 auxiliary cores and additional outer screen, in PVC sheath,
∅12 mm; extension: PMK, order no. 50005277
Type: Coaxial cable with 4 auxiliary cores and additional outer screen, in PVC sheath,
∅7.2 mm; extension: CYK 71, order no. 50085333
CPK 1
Outer screen
PA / P
M
Ref.
pH
bn
Coax bk
PM
pH
cpk1e.cdr
Fig. 4.9 Measuring cable CPK 1
PM / PA
pH or Redox
bn
Temperature
ye
gn
wt
Reference
or redox
rd/bl
CPK 2
PM / PA
pH or redox
Ref. or redox
Pt 100
Outer screen
The end of the cable CPK 2
must be terminated by the user
cpk2e.cdr
Fig.4.10 Measuring cable CPK 2
Outer screen
CPK 7
PA / PM
Ref.
pH
bn
ye
gn
Coax bk
wt
P
t
1
00
PM
pH + Pt 100
cpk7e.cdr
Fig. 4.11 Measuring cable CPK 7
liquisys CPM 252 Installation
Endress+Hauser 15

Cable installation
Install the ready-made special measuring cable as shown in figure 4.12:
●Insert the cable through a Pg cable gland into the wiring space.
●Strip approx. 3 cm of the woven screen and fold it back over the cable insulation.
●Insert the crimping ring attached to the supplied screen connection over the prepared woven
screen and pull the ring tight with a pair of pliers.
●Connect the litz wire on the screen connection to the terminal bearing the ground symbol.
●Establish the remaining connections according to the connection diagram (see figure 4.6).
●Tighten the Pg cable gland.
gn/ge
gn/ye
cpk1-7m3.cdr
Fig. 4.12 Screen connection for CPK 1, CPK 7
Installation liquisys CPM 252
16 Endress+Hauser

Connection accessories
Junction box VBA
Junction box for connection cables over 20 m
long between assembly and transmitter.
Comes with 4 Pg cable glands for cable entry
(Pg 13.5 and Pg 16) and 10 high-impedance
insulated screw terminals for single-core
connection.
Dimensions: 120 x 120 x 55 mm (L x W x H);
Material: plastic; protection type: IP 65
Order no.: 50005276
Caution:
To avoid measuring errors caused
by humidity bridges on the pH
connecting line, please check the
desiccant bag regularly and replace
if necessary (depending on the
ambient conditions).
4.5 Packaging and disposal
Packaging
Packaging must provide shock and moisture protection. Optimal protection is provided by the
original packaging materials.
Disposal
Note:
Electronic components to be disposed of are considered special waste! Please
observe local regulations for disposal!
120
90
110
Height 55 mm
vba-dose.tif
180
Mounting hole
Fig. 4.15 Dimensions of junction box VBA
liquisys CPM 252 Installation
Endress+Hauser 17

5 First start-up
5.1 Measures before first power-up
Note:
Familiarise yourself with the operation of the measuring instrument before switching it
on for the first time!
Caution:
Before power-up, check that all connections have been properly made!
Make sure that the electrode is immersed in the medium to be measured or a buffer
solution. This ensures that a plausible value will be displayed.
In the case of configurations with potential matching, make sure that the pin contacts
the medium or buffer solution.
Warning:
Before power-up make sure that there is no risk of damage to the system the
instrument is a part of; for example, due to valves or pumps that might operate in an
uncontrolled manner, etc.
First start-up liquisys CPM 252
18 Endress+Hauser