WIKA DW03 Series User manual

INSTRUCTION MANUAL NI-210WE
Rev. 4 04/20
DIFFERENTIAL PRESSURE SWITCHES FOR CONTROL ON DRY AND
CLEAN GAS SERIES DW03 & DW05
All data, statements and recommendations supplied with this manual are based on information believed by us to be reliable. As the conditions of
effective use are beyond our control, our products are sold under the condition that the user himself evaluates such conditions before following our
recommendations for the purpose or use foreseen by him.
The present document is the property of ALEXANDER WIEGAND SE &Co and may not be reproduced in any form, nor used for any pur-pose other
than that for which it is supplied.
WEATHERPROOF AND INTRINSICALLY SAFE: SERIE DW03 WEATHERPROOF AND INTRINSICALLY SAFE: SERIE DW05
A
High pressure connection
BLow pressure connection
CCable entr
y
Weight 2,2 kg (dimensions in mm)
A
High pressure connection
BLow pressure connection
CCable entr
y
Weight 8,2 kg (dimensions in mm)
For surface mounting use two screws M6. For surface mounting use six screws M6.
NOTE: dimensions and weights are not binding unless released on certified drawings.
CAUTION
 Before installing, using or carrying out maintenance on the instrument it is necessary to read and understand the indications given in the
attached Instruction Manual.
 The instrument must only be installed and maintained by qualified personnel
 INSTALLATION IS TO BE CARRIED OUT ONLY AFTER CHECKING THAT INSTRUMENT CHARACTERISTICS ARE CONSISTENT
WITH PROCESS AND PLANT REQUIREMENTS.
 The functional features of the instrument and its degree of protection are shown on the identification plate fixed to the case.
CONTENTS:
1
GENERAL NOTES
2 OPERATING PRINCIPLE
3 MODEL CODE
4 IDENTIFICATION PLATE AND MARKINGS
5 SET POINT REGULATION
6 SET POIT CALIBRATION
7 MOUNTING AND CONNECTIONS
8 INSTRUMENT PLUMBING
9 SAFETY INTEGRITY LEVEL (SIL) INSTALLATION REQUIREMENTS
10 PUTTING INTO OPERATION
11 VISUAL INSPECTION
12 FUNCTIONAL VERIFICATION
13 STOPPING AND DISMOUNTING
14 DISPOSAL
15 TROUBLESHOOTING
SAFETY INSTRUCTIONS FOR USE IN HAZARDOUS ATMOSPHERES.
RECOMMENDATIONS FOR PRESSURE SWITCH SAFE USE.
RELATED DOCUMENT
To authenticated document with certificate
N°IECEx PRE 16.0074X

INSTRUCTION MANUAL NI-210WE
Rev. 4 04/20
2 di 6
1 GENERAL NOTES
1.1 FOREWORD
This instrument is suitable for use on air or clean gas free from
vapours that may condensate inside its measuring chambers.
The wrong choice of a series or a model, as well as the incorrect
installation, lead to malfunction and reduce instrument life.
Failure to follow the indications given in this manual can cause
damage to the instrument, the environment and persons.
1.2 ALLOWED OVERRANGE
Pressures exceeding the working range can be occasionally
tolerated provided they remain within the limits stated in the
instrument features (vacuum or proof pressure). Continuous
pressures exceeding the working range can be applied to the
instrument, provided they are clearly stated in the instrument
features. The current and voltage values stated in the technical
specifications and ratings must not be exceeded. Transitory
overranges can have a destructive effect on the switch.
1.3 MECHANICAL VIBRATIONS
Can generally lead to the wearing of some parts of the instrument
or cause spurious action. It is therefore recommended that the
instrument be installed in a place where there are no vibrations.
In cases where this is impossible it is advisable to take measures
to lessen the effects (elastic supports, installation with the pin of
the microswitch positioned at right angles to the vibration plane,
etc.).
1.4 TEMPERATURE
Due to the temperature of both the environment and the process
fluid, the temperature of the instrument could exceed the allowed
limits (normally from -10° to +40°C). Therefore, in case it does,
suitable measures (protection against heat radiation, fluid
separators, cooling coils, heated lockers) must be taken. The
process fluid or its impurities must not in any case solidify inside
the instrument chambers
2 OPERATING PRINCIPLE
The differential pressure acting on a diaphragm, produces a force
directly proportional to the differential pressure. This force is
counteracted by an helical spring whose preload is adjusted
through a proper screw. When the force balance is overcome,
the diaphragm moves and actuates the microswitch through a
rigid tip
The microswitch is of the snap acting type with automatic reset.
When the pressure moves away from the set values, returning
towards the normal values, the switch is reset. The dead band
(difference between the set point value and the reset value) is
fixed.
3 MODEL CODE
See Annex 1
4 IDENTIFICATION PLATE AND MARKINGS
The instrument is fitted with a metal plate bearing all its functional
characteristics and in case of intrinsic safety execution the
markings prescribed by standard IEC/EN 60079-0 (see Fig.1)
Fig. 1 – Nameplate
1 Notified body that issued the type certificate and number of said
certificate.
2 CE marking and identification number of the notified body
responsible for production surveillance.
3 Apparatus classification according to ATEX 2014/34/EU
directive.
4 Type of protection and ambient temperature limits of operation.
The following table gives the relationship between hazardous
areas, Atex Categories and Equipment Protection Level (EPL)
listed on the instrument nameplate
Hazardous area
Categories
according to
2014/34/EU
Directive (ATEX)
EPL
Gas, vapours, fog Zone 0 1G Ga
Gas, vapours, fog Zone 1 2G or 1G Gb or Ga
Gas, vapours, fog Zone 2 3G, 2G or 1G Gc, Gb or Ga
Dust Zone 20 1D Da
Dust Zone 21 2D or 1D Db or Db
Dust Zone 22 3D, 2D or 1D Dc, Db or Da
5 SET POINT REGULATION
The set point can be adjusted by means of a screw (for
adjustment) to snap when the pressure reaches (increasing or
decreasing) the desired value (set point). The instrument is
usually supplied with the switch adjusted at the setting range
value nearest to zero (factory calibration). The instrument is
supplied with a label showing the set point calibration value. With
factory calibration the values are not indicated, as these are
temporary and will be modified with the definitive values. Prior to
installation the instrument must be calibrated and the definitive
calibration values written on the label.
If the instrument has been ordered with a specific calibration,
check the calibration values marked on the relevant label, prior
to installation.
The position of the adjustment screw is given in figure 2.
Fig. 2 - Electrical connections and adjustment screws
1 - Set point calibration screw
2 - Terminal block
Microswitch electrical circuit: State of the contacts at atmospheric
pressure
Designation of the contacts:
C - common
NA - Normally open
NC - Normally closed
The effect that the direction of rotation of the adjustment screw
has is described on the label.
6 SET POIT CALIBRATION
In order to proceed with the calibration and the periodical
functional verification of the instrument a suitable calibration
circuit (Fig. 3) and an adequate pressure source is required.
The calibration circuit used for the calibration of these
instruments must have:
- a big internal volume (5 litres or bigger) in order to reduce the
effect of volumetric variation (and therefore of pressure) caused
by the sensing element of the pressure switch during the snap
action.
- installed in a thermally stable place in order to guarantee
stability to the pressure inside the circuit used for the calibration.
Have to be considered that in a closed circuit with the internal
pressure equal to the atmospheric pressure, the variation of
temperature of 1°C causes in the circuit a pressure variation of
3,4 mbar. The maximum inlet pressure must not exceed the
lesser of overpressure allowed by the pressure switch and the
test gauge.

INSTRUCTION MANUAL NI-210WE
Rev. 4 04/20
3 di 6
The test instrument should have a measurement range
approximately equal to or slightly wider than the pressure switch
range and should have an accuracy consistent with the accuracy
required to calibrate the set point.
For example DW03 range 0,7/16mbar the accuracy of the test
gauge must be ± 0,04 mbar to calibrate the set point with an
accuracy of ± 0,16 mbar (1% of the adjustable span).
Fig. 3 – Calibration circuit for instrument with adjustable range less
than 60 mbar
1- Pressure switch
2- Test gauge
3- Inlet valve
4- Volumetric pump
5- Capacity
6- Outlet valve
6.1 PRELIMINARY OPERATIONS
Remove the blocking device fixed to the side of the instrument
case (Fig. 4). Remove the cover by rotating it in an anticlockwise
direction.
Fig. 4 - Pressure switch blocking device
a) Blocking gap
b) Blocking bracket
c) Blocking nut
d) Plumbing wire
6.2 CALIBRATION CIRCUIT AND OPERATIONS
Prepare the calibration circuit as indicated in Fig.3.
The warning lamps should be connected to contact in the NO or
NC position according to the required contact action.
Connection of C and NO terminals
• If the circuit is open at the working pressure, the switch closes
the circuit as the pressure increases when the desired value is
reached.
• If the circuit is closed at the working pressure, the switch opens
the circuit as the pressure decreases when the desired value is
reached.
Connection of C and NC terminals
• If the circuit is closed at the working pressure, the switch opens
the circuit as the pressure increases when the desired value is
reached.
• If the circuit is open at the working pressure, the switch closes
the circuit as the pressure decreases when the desired value is
reached.
The pressure switch must be mounted in the normal installation
position, i.e. with the pressure connection pointing downwards.
The pressure connection + (or H) of the instrument must be
connected to the pressure source and the connection - (or L) has
to be left to the atmosphere
Increase the pressure in the circuit up to the desired set point
value for the first microswitch. Use a wide bladed screwdriver, as
indicated on the label, turn the screw until the relative lamp turns
on (or turns off).
6.3 CHECK OF SET POINT
Generate the normal working pressure and wait the pressure
stabilisation. Vary the pressure into the circuit and record the set
point value. Write the set point values on the adhesive label.
Note: the repeatability should be checked verifying for three
times the set point (Pi) starting always from the same pressure
value (Pw). The pressure cycle should be slowly to give the
possibility to record the set point with enough accuracy.
6.4 FINAL OPERATIONS
Disconnect the instrument from the calibration circuit.
Take the cover, ensure that the sealing gasket is correctly fitted
into its seat, and insert the cover onto the case, with the blocking
gap positioned in correspondence to the blocking bracket.
Turn the cover clockwise closing it tightly. Mount the blocking
device as in Fig. 4.
Mount on pressure connection, cable entry and adjustment screw
the protection caps supplied with the instrument.
Caution: The protection caps should only be definitively
removed during the connection steps.
7 MOUNTING AND CONNECTIONS
7.1 MOUNTING
Surface mount the instrument by means of the holes provided,
(see Fig.10 and 11). In case of surface or panel or rack mounting
the instruments can be mounted side by side (see Fig.12 & 13).
The chosen position must be such that vibrations, the possibility
of shocks or temperature changes are within tolerable limits. The
instrument must be positioned higher than the pipe inlet (Fig.14).
7.2 PRESSURE CONNECTIONS
Connecting lines are an integral part of the instrument in
transmitting the measured variable from the measuring point to
the instrument.
The diameter and length of the two connecting lines between
instrument and pressure taps are to be such as not to cause
dampening or lag in transmitting the differential pressure.
Run connecting lines always sloping down from instrument to
process so that possible condensate flows towards process
(avoid forming of siphons).
For a correct installation (see Fig 14) it is necessary to:
Mount a shut-off valve with drain (root valve) on each process
pipe inlet to allow the instrument to be excluded and the
connection tubing to be drained. It is recommended that said
valve has a capstan blocking device aimed at preventing it being
activated casually and without authorisation.
Mount a 3 valve manifold near the instrument to permit possible
functional verification on site and removal of the instrument. It is
recommended that the manifold is made up of two service valves,
one by-pass valve and two suitably connected drain plugs. The
three valves with the drains can be reunited by a single device
called a “Three valve manifold”
Mount a three piece joint onto the threaded attachment of the
instrument to permit the easy mounting or removal of the
instrument itself.
Carry out the connection using a flexible tube in such a way that
variations in the temperature of the tube itself do not force the
instrument attachment.
Ensure that all the pressure connections are airtight. It is
important that there are no leakage in the circuit.
Close root valves, the two service valves, drain plugs and open
the by-pass valve.

INSTRUCTION MANUAL NI-210WE
Rev. 4 04/20
4 di 6
7.3 ELECTRICAL CONNECTIONS
It is recommended to carry out the electrical connections
according to the applicable standards. In case of intrinsic safety
instrument see also the Standard IEC-60079-14. If the electrical
connection is carried out in a protected tube, it shall be made so
that condensate is prevented from entering instrument enclosure
To guarantee the ingress protection IP66 and prevent loosening
of the blocking joint or cable glands, it is prescribed to seal the
threads with an anaerobic sealant. For example, use a sealant
like Loctite ® 542.
The installation of the cable gland or three-piece joint should be
as per Fig 5.
Fig. 5 – Installation of electrical connection
With the instrument into the final position provided that the
electric line is not energize, remove the cover and make the
electrical connection to the terminal block (see Fig. 2).
If the ambient temperature exceeds 60 °C is recommended to
use cables suitable for operating temperatures of at least 105 °C.
Flexible cables with a maximum section of 1,5 mm
2
(16AWG) are
recommended using the pre-insulated crimp ring terminal.
Ensure that no deposits or wire ends remain inside the case.
The relevant parameters for intrinsic safety are listed on the
nameplate of the instrument.
The tightening of the cable gland or the three-piece joint must be
performed as shown in Fig.6.
Fig.6 – Installation of the cable gland
As soon as connection steps are completed, mount the cover on
and make sure it is tight and blocked (see fig. 4).
7.4 CONNETTOR 7 POLES TYPE MIL-5015 FOR
WEATHER PROOF INSTRUMENT
The free connector, supplied with the instrument, is able to
accept multicore cables with maximum outer diameter 11 mm. It
is recommended flexible cables with single-conductor with a
maximum section of 1.5 mm2 (16AWG).
The cable have to be prepared as per fig.7.
Fig. 7 – Cable preparation
A= 53mm
B= 30mm
C= 6,5 mm
The single stripped conductor has to be crimped with each
contact pin. For the electrical connections and for the assembly
follow Fig.8.
Fig.8 – Free connector assembly
1- Cable
2- Heat Shrink Boot
3- Clamp
4- Extender
5- Ferrule
6- Insulator for pin contacts
7- Pin contacts
8- Shell
The wiring diagram is according Fig.9.
Fig.9 – Wiring diagram MIL C-5015
CONTACT FUNCTION
A 1-NA Micro 1: Normally open
B 1-NC Micro 1: Normally closed
C 1-C Micro 1: Common
G Ground Internal grounding connection
Once the crimping and assembly activities of the free connector
are finished, make sure that all the parts are tight. Screw the
bayonet and tighten it to assure the instrument degree of
protection
7.5 GROUNDING CONNECTIONS
The instrument is supplied with two grounding connections, one
external and one internal. The connections are suitable for a
earthing wires of 4 mm
2
section (fig. 2).
8 INSTRUMENT PLUMBING
8.1 PLUMBING CALIBRATION DEVICE
This plumbing is necessary in order to prevent possible
tampering of set point. It is obtained with a stainless steel wire
inserted into the holes provided on the device (Fig.4). It is to be
done at the end of calibration.
8.2 PLUMBING ACCESS COVER TO TERMINAL
BLOCK
This plumbing is necessary in order to prevent possible
tampering of electric wiring. It is obtained with a stainless steel
wire (d) inserted into the holes of screws (c) and of blocking
racket (b) (Fig. 4). It is to be made after installing instrument on
the plant.
9 SAFETY INTEGRITY LEVEL (SIL) INSTALLATION
REQUIREMENTS
The pressure switch has been evaluated as Type A safety related
hardware. It has an hardware fault tolerance of 0 if it is used in
one out one configuration (1oo1). The installation has to be
designed to allow a proof test to detect dangerous undetected
fault using, as example, the following procedure:
- Take appropriate action to avoid a false trip
- Force the switch to reach a define max or min threshold
value and verify that output goes into the safe state.
- Force the switch to reach a define normal threshold value
and verify that output goes into the normal state.
- Repeat the check two times evaluating average set point
value and repeatability,
- Restore the loop to full operation
- Restore normal operation
A
B
C
D
F
G
E

INSTRUCTION MANUAL NI-210WE
Rev. 4 04/20
5 di 6
10 PUTTING INTO OPERATION
The instrument comes into operation as soon as the root valves
are opened and then, afterwards, the service valve attached to
the instrument + (H) inlet pipe is opened, the by-pass valve
closed and the service valve attached to the instrument – (L) inlet
pipe is opened. Any possible drainage of the connection tubing
can be carried out by opening the drains positioned on valves.
Do not dispose of the process fluid into the environment, if this
can cause pollution or damage to people
11 VISUAL INSPECTION
Periodically check the external condition of the enclosure. There
should be no trace of leakage of process fluid outside the
instrument.
In case of intrinsic safety instruments, inspections of the electrical
installation are to be carried out also according to customer
procedures and at least in accordance with IEC-60079-17.
The intrinsic safety instruments installed in explosive
atmospheres for the combustible dust presence, must be
periodically cleaned up externally in order to avoid dust
accumulating.
12 FUNCTIONAL VERIFICATION
This will be carried out according to the Customer’s control
procedures and because of their particular operating principle,
have to be functional inspected every year as minimum if used
as an alarm of max pressure
The instruments can be verified on the plant if installed as
illustrated in Fig. 14.
To avoid any risk it is recommended check the set point on site
without open the cover, without dismount the cable gland and
without unplugging the power cable.
The intrinsic safety instruments may be checked on site only if
the apparatus used are suitable for explosive atmosphere.
If this is not the case it is necessary remove the instrument from
the plant, and carry out the verification in a testing room.
If the verification of the set point is performed unplugging the
power cable from the terminal block it is recommended de-
energize the instrument to avoid any electrical hazard.
Verification consists in check the calibration value and possibly
regulating the adjustment bush (see §5).
13 STOPPING AND DISMOUNTING
Before proceeding with these operations ensure that the plant or
machines have been put into the conditions foreseen to allow
these operations.
With reference to Figures 14
Remove the power supply (signal) from the electrical line. Close
the root valves (6) and open the by-pass valve. Open the drains
on the root valves slowly.
Do not dispose of the process fluid into the environment, if this
can cause pollution or damage to people.
Unscrew the three-piece joint (1).
Unscrew the cable gland (9).
Remove the cover of the instrument and disconnect the electrical
cables from the terminal block and earth screws.
Remove the screws fixing the case to the panel and remove the
instrument, taking care to slide the electrical conductors out from
the case.
Mount instrument cover. Insulate and protect cables around, if
any. Temporarily plug pipes not connected to the instrument.
In case of intrinsic safety instruments it is recommended to follow
- at least – the standard IEC-60079-17 for the withdrawal from
service of electrical apparatus.
14 DISPOSAL
The instruments are mainly made of stainless steel and
aluminium and therefore, once the electrical parts have been
dismounted and the parts coming into contact with fluids which
could be harmful to people or the environment have been
properly dealt with, they can be scrapped.
15 TROUBLESHOOTING
IMPORTANT NOTE: operations involving replacement of essential components must be carried out at our workshop this is to guarantee
the user the total and correct restoration of the product original characteristics.
MALFUNCTION PROBABLE CAUSE REMEDY
Set point shift
 Permanent deformation of the sensitive element
due to fatigue or non-tolerated over-ranges
 Variation of the elastic features of the sensitive
element due to its chemical corrosion.
 Recalibrate or replace the sensitive element.
 Recalibrate or replace the sensitive element with
another made of a suitable material.
Slow response
 Clogged or obstructed connection line.
 Root or service valve partially closed.
 Check and clean line.
 Open valve.
No actuation or
undue actuation
 Root or service valve closed.
 By-pass valve open.
 Microswitch contacts damaged.
 Loosened electrical joints.
 Interrupted or short-circuited electrical line.
 Open the valve.
 Close the valve.
 Replace the microswitch.
 Check all electrical joints.
 Check the conditions of the electrical line.
Undue actuation
 Accidental shocks or excessive mechanical
vibrations.
 Modify the mounting.
Fig.10 – DW03 wall mounting Fig.11 – DW03 wall mounting

INSTRUCTION MANUAL NI-210WE
Rev. 4 04/20
WIKA Alexander Wiegand SE & Co. KG
Alexander-Wiegand-Straße 30
63911 Klingenberg
German
y
Tel. [phone]
Fax [phone]
E-Mail [e-mail]
www.wika.de
Kommanditgesellschaft: Sitz Klingenberg –
Amtsgericht Aschaffenburg HRA 1819
Komplementärin: WIKA Verwaltungs SE & Co. KG –
Sitz Klingenberg – Amtsgericht Aschaffenburg
Komplementärin:
WIKA International SE - Sitz Klingenberg -
Amtsgericht Aschaffenburg HRB 10505
Vorstand: Alexander Wiegand
Fig. 12 – DW03 - Rack mounting Fig. 13 – – DW03 - Rack mounting
Fig. 14 - Example of connections -
1 - Three pieces fitting
2 - Three valves manifold
3 - Three pieces fitting
4 - Piping
5 - Three pieces fitting
6 - Root valve with drain
7 - Filter or nozzle
8 - Check inlet and drain plug
9 – Cable gland
Annex 1 – Model code
1 MODEL CODE
DW
For further information see
datasheet
1.1 Sensor code -
Low differential pressure
H
High differential pressure
1.2 Line (static) pressure
03
Max line pressure 10 bar
05
Max line pressure 40 bar
1.3 Type of Electric Contact UW
Silver
UN
Silver
UG
Gold
2 Options Example: Intrinsic Safety execution