Ashcroft D7 series Manual

IM-B7D7T7/ATEX-E-Rev A02/2016Page 1 of 19
P/N 095I401-02EN
Installation and Maintenance
Instruction Manual
Pressure switch model B7, differential pressure switch model D7 and
temperature switch model T7
for explosion risk areas pursuant to Directive 94/9/EC (ATEX) / IEC
In the following configuration:
•B7###CN### pressure switch
•D7###CN### differential pressure switch
•T7###CN### temperature switch
B7
Pressure switch D7 Differential pressure
switch
T7
Temperature switch

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Table of contents:
1General remarks.........................................................................................................................................................4
1.1 Purpose of this Manual........................................................................................................................................4
1.2 Symbols...............................................................................................................................................................4
1.3 Limits of liability ...................................................................................................................................................4
1.4 Copyright.............................................................................................................................................................4
1.5 Warranty..............................................................................................................................................................4
1.6 Manufacturer’s address, customer services........................................................................................................4
2Safety..........................................................................................................................................................................4
2.1 General sources of hazards................................................................................................................................4
2.2 Operator’s responsibility......................................................................................................................................5
2.3 Staff qualifications (target group assessment)....................................................................................................5
2.4 Signs/Safety markings.........................................................................................................................................5
2.5 Safety equipment ................................................................................................................................................5
2.6 Environmental protection.....................................................................................................................................5
3Use in explosion risk areas pursuant to Directive 94/9/EC (ATEX) ...........................................................................6
3.1 B7/D7/T7 flameproof enclosure and dust ignition protection by enclosure.........................................................6
4Technical data ............................................................................................................................................................7
5Labeling on the device................................................................................................................................................7
5.1 Labeling on the device for explosion risk areas (ATEX).....................................................................................7
6Construction and function...........................................................................................................................................7
6.1 Overview..............................................................................................................................................................7
6.2 Description of function.........................................................................................................................................7
6.3 Description of components..................................................................................................................................7
6.4 Accessories.........................................................................................................................................................8
7Transport ....................................................................................................................................................................8
7.1 Safety ..................................................................................................................................................................9
7.2 Transport inspection............................................................................................................................................9
7.3 Storage................................................................................................................................................................9
8Assembly/Installation..................................................................................................................................................9
8.1 Safety ..................................................................................................................................................................9
8.2 Preparations (requirements for the installation location).....................................................................................9
8.3 Mounting/Installation .........................................................................................................................................10
8.4 Starting up and setpoint adjustment..................................................................................................................11
8.5 Subsequent relocation of the switch (by the customer)....................................................................................12
9Servicing...................................................................................................................................................................12
9.1 Safety ................................................................................................................................................................13
9.2 Check on function, and recalibration.................................................................................................................13
9.3 Cleaning and maintenance ...............................................................................................................................13
10 Faults ....................................................................................................................................................................13
10.1 Safety.............................................................................................................................................................13
10.2 Conduct in the event of faults........................................................................................................................13
10.3 Fault table......................................................................................................................................................13
10.4 Conduct following fault rectification...............................................................................................................13

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11 Removal, disposal.................................................................................................................................................13
11.1 Safety.............................................................................................................................................................13
11.2 Removal.........................................................................................................................................................13
11.3 Disposal.........................................................................................................................................................14
12 Appendix...............................................................................................................................................................14
12.1 Data sheet for switches B7, D7 and T7.........................................................................................................14
12.2 EG Declaration of Conformity........................................................................................................................15
12.3 IECEX Declaration of conformity...................................................................................................................16

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1 General remarks
1.1 Purpose of this Manual
This Operating Manual contains fundamental and essential advice to be followed for the installation, operation and
servicing of the device. It must be read without fail before assembly and start-up of the device by the fitter, the
operator and the specialist personnel responsible for the device. This Operating Manual must be available at the point
of use at all times.
The following sections about general safety information (2) and also the following specific advice regarding the
intended purposes (2.2) and through to disposal (11.3) contain important safety information which, if not followed, may
result in risks for people and animals, or to property and buildings.
1.2 Symbols
Warning!
This indicates a possibly hazardous situation where failing to follow advice may result in risks to people,
animals, the environment and buildings.
Information!
This emphasizes key information for efficient, fault-free operation.
1.3 Limits of liability
Failure to respect this safety information, the envisaged uses or the limit values relating to use indicated in the
technical data for the device may result in risk or to injury to people, the environment or the plant.
Claims for compensation for damage against the device supplier are excluded in such an eventuality.
1.4 Copyright
This Operating Manual may only be copied and passed on as a complete document without the special permission of
the publisher.
1.5 Warranty
For the product described here, we offer a warranty pursuant to Section 6 Guarantee in Respect of Defects in our
General Terms and Conditions of Delivery and Payment.
1.6 Manufacturer’s address, customer services
Ashcroft Instruments GmbH
Max-Planck-Strasse 1
D-52499 Baesweiler. Germany
Tel.: [phone]
Fax.: [phone]
E-mail: [e-mail]
Web: www.ashcroft.eu
2 Safety
2.1 General sources of hazards
Pressure and temperature switches are generally a constituent part of a control and measurement system Pressure
switches are pressurized parts where failure can result in hazardous situations. The selection of switches should be
made in accordance with the applicable standards, regulations and engineering practice.
The devices are only to be used for the intended purpose as described by the manufacturer.
The devices are precision built agency approved control device which features a mechanical snap action switch.
Controllers are available for operation on pressure or vacuum (B7), differential pressure (D7) or temperature (T7) with
fixed differential.
The integrated switching elements are SPDT micro switches, in case if intrinsically safe operation supplied by isolating
switch amplifiers with certified intrinsically safe power circuits. If the set limit values are exceeded, the output circuits
are opened or closed.

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For each use scenario, the corresponding set-up regulations must be respected. If used in explosion risk areas, the
following conditions are to be respected for the individual finishes.
2.2 Operator’s responsibility
Safety instructions for proper operation of the device must be respected. They are to be provided by the operator for
use by the respective personnel for installation, servicing, inspection and operation. Risks from electrical energy and
from the released energy of the medium, from escaping media and from improper connection of the device must be
eliminated. The details for this are to be found in the corresponding applicable set of regulations, such as DIN EN,
UVV (accident prevention regulations) and in sector-specific instances of use (DVWG, Ex-. GL, etc.) the VDE
guidelines and the regulations supplied by local utilities companies.
The device must be taken out of service and secured against inadvertently being restarted, if the presumption is that
risk-free operation is no longer possible (see Chapter 10: Faults).
Conversion works or other technical alterations to the device by the customer are not permitted. This also applies to
installation of spare parts. Possible conversations or alterations may only be carried out by the manufacturer.
The operational safety of the device is only guaranteed where it is used for its intended purpose. The specification of
the device must be adapted to the medium used in the plant. The limit values indicated in the technical data must not
be exceeded.
The safety information detailed in this Operating Manual, existing national regulations for accident prevention, and the
operator’s internal regulations regarding working, operations and safety must be respected.
The operator is responsible for all specified servicing, inspection and installation works being carried out by authorized
and qualified specialists.
2.3 Staff qualifications (target group assessment)
The device may only be installed and started up by specialist staff who are familiar with installation, start-up and
operation of the product.
Specialist staff are people who are able to assess the work assigned to them on the basis of their specialist training,
their knowledge and experience and their knowledge of the relevant standards, and can identify possible risks.
For devices in explosion-protected configuration, these staff must have been trained or instructed in, or be authorized
for, working on explosion-protected devices in potentially explosive plants.
2.4 Signs/Safety markings
The switch and its surrounding packaging carry markings. These markings show the article number, measurement
range and manufacturer. The switches can be provided with additional signs and safety markings advising on special
conditions:
Advice on calibration
Ex (for ATEX configuration)
2.5 Safety equipment
This device is fitted with safety locking devices and electrical earthing. The detecting element, when filled, secures the
operating rod preventing removal and contains two venting holes that ensure that the interior of the enclosure is not
subject to pressure greater than 2 lb/ft².
2.6 Environmental protection
This device contains electrical components. The provisions set out in the WEEE regulation EU directive 2002/96/EC
on electrical and electronically equipment are to be respected, and the products are registered at the EAR under the
number DE 26646349.

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3 Use in explosion risk areas pursuant to Directive 94/9/EC (ATEX)
3.1 B7/D7/T7 flameproof enclosure and dust ignition protection by enclosure
Area of use:
Explosion risk areas Zone 1 and 2, and 21 and 22, risk from gases and dry dust
Permitted temperatures:
Permitted ambient temperature -20°C to +60 °C.
Permitted medium temperature in the pressure switch < 85 °C.
Warning! With gaseous media, the device temperature may increase due to compression heat. In
such cases, the rate of the pressure change must be regulated or the permitted temperature of the
measuring medium reduced.
To avoid additional temperature increase, the devices should not be exposed to direct exposure to sunlight when in
operation!
EU design type test certification:
The Ashcroft®7XX Series Pressure & Temperature Switches comprise a cylindrical two-part enclosure, consisting of a
base and cover, manufactured from die-cast aluminum 380 or stainless steel 316L. The cover treads into the base and
is secured against loosening by a 10-32 UNF-2B socket head cap screw. The base houses a range of various switch
elements and an operating rod. The base has three bosses at 90° apart on its side walls. The two opposing bosses
each contain a ¾” NPT cable entry port while the other boss provides a facility allowing connection to different
detecting elements retained by a mounting plate secured by six M5 x 12 hexagon head screws. The detecting
element, when filled, secures the operating rod preventing removal and contains two venting holes that ensure that the
interior of the enclosure is not subject to pressure greater than 2 lb/ft².
Switch element ratings up to:
15 A 125/250/480 VAC
6 A 34 VDC
500 mA 125 VDC
250 mA 250 VDC
Compliance with the Essential Health and Safety Requirements, with the exception of those listed in the schedule to
EC-type examination certificate, has been assured by compliance with the following documents:
This product complies with the following standards:
IECEx ATEX
EN 60079-0: 2011 Ed 6
EN 60079-1: 2007
EN 60079-31: 2013
EN 60079-0: 2012
EN 60079-1: 2007
EN 60079-31: 2013
The documentation has been filed with SIRA (see declaration of conformity).
Labeling:
II 2GD
Ex db IIC T6 Gb
Ex tb IIIC T85°C Db IP 6X
(Ta = -20°C to +60°C)

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4 Technical data
The detailed technical information can be found in the documents in the Appendix, Chapter 12.
5 Labeling on the device
The label with the serial number and type designation is located on the outside of the housing. The materials identifier
is encoded in the type designation.
5.1 Labeling on the device for explosion risk areas (ATEX)
The label with the marking for explosion risk areas is located on the outside of the housing.
Switch certified flameproof
enclosure or dust ignition
protection by enclosure:
#7###CN###
6 Construction and function
6.1 Overview
B7 pressure switch D7 differential pressure switch T7 temperature switch
Figure 1
6.2 Description of function
The Ashcroft pressure switch is a precision built agency approved control device which features a mechanical snap
action switch. Controllers are available for operation on pressure or vacuum, differential pressure or temperature with
fixed or variable differential. Also manual reset types for operation on increasing or decreasing pressure. The manual
reset types remain tripped until reset by pressing a button on top of the enclosure. Various wetted material
constructions for compatibility with a range of pressure media may be obtained.
6.3 Description of components
6.3.1 Process adapter of pressure switch B7

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B-Series pressure and vacuum switches use two different actuators depending on setpoint requirements. For setpoints
between 2 and 3000 psi, the simple, rugged diaphragm-sealed piston actuator is used. This design features high
reliability and choice of actuator seal materials for virtually every application. An optional welded design is also
available for setpoints up to 1000 psi for maximum reliability. This design is available in 316 SS or Monel.
For setpoints between 4.5 and 150 inches of H2O, a large diaphragm is used for increased sensitivity with good
choice of materials of construction.
Erläu ter ung, z usä tzl ich ei n H i nweis :
6.3.2 Process adapter of pressure switch D7
Differential pressure models use a unique, dual diaphragm-sealed piston design that features very high static
operating pressures and small size.
For setpoints between 1.5 and 150 inches of H2O, a large diaphragm is used for increased sensitivity with good
choice of materials of construction.
6.3.3 Process adapter of temperature switch T7
B-Series temperature switches feature a SAMA Class II vapor pressure thermal system. This system provides quick,
accurate response to process temperature changes with negligible ambient temperature effects. This is inherent in the
design due to the precise relationship that exists between temperature and pressure according to the vapor pressure
laws. A wide selection of sensing bulb and armored capillary lengths is available. The vapor pressure system design
features small bulb sizes, making installation easy and cost-effective.
6.3.4 Set point adjustment
A single setpoint adjustment nut (7/8”) is located centrally at the bottom on the inside of the enclosure.
6.3.5 Micro switch
Standard electrical switch is SPDT, available with various electrical characteristics. Two SPDT switch elements
mounted together are available except on variable Deadband and manual reset types.
Microswitch Code Electrical rating
Single Dual VAC VDC
20 61 15 A, 250 V 0,4 A, 120 V
21 65 5 A, 250 V
22 67 5 A, 250 V 2,5 A, 28 V
23 22 A, 250 V
24 64 15 A, 480 V 0,25 A, 250 V
25 10 A, 250 V 10 A, 250 V
26 62 15 A, 250 V 0,4 A, 120 V
27 63 15 A, 250 V
28 15 A, 250 V
29 15 A, 250 V
31 70 1 A, 250 V 50 mA, 60 V
32 68 11 A, 250V 5 A, 30 V
42 71 1 A, 125 V
50 15 A, 250 V
35 10 A, 250 V 0,3 A, 250 V
Table 1: Micro switch electrical ratings
6.3.6 Enclosure
The Ashcroft snap action pressure switch is furnished in the flameproof NEMA 7 & 9 and ATEX Ex db and dust ignition
protected ATEX Ex tb enclosure styles. Enclosure is epoxy coated aluminum casting or optional stainless steel 316L.
6.4 Accessories
Please contact the manufacturer regarding special tools and accessories.
7 Transport

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7.1 Safety
The switch should be protected against the effects of knocks and impacts. The device should only be transported in
the packaging provided. The device should only be transported in a clean condition (free of residues of measuring
media).
7.2 Transport inspection
The delivery must be checked for completeness and damage during transport. In the event of damage during
transport, the delivery must not be accepted, or only accepted subject to reservation of the scope of the damage being
recorded and, if necessary, a complaint initiated.
7.3 Storage
The switch must be stored in dry, clean conditions, within a temperature range of -40 to +60 °C, protected against
direct exposure to sunlight and protected against impact damage.
8 Assembly/Installation
8.1 Safety
To ensure safe working during installation and servicing, suitable shut-off valves must be installed in the plant (see 6.4
Accessories), enabling the device:
To be depressurized or taken out of operation;
To be disconnected from the mains supply for repair or checks within the relevant plant;
Or to enable function tests of the device to be performed “on site”.
During the works to mount/install the switch, the plant must be protected against being switched back on.
8.2 Preparations (requirements for the installation location)
A check on suitability of the device for the medium to be measured, the scope of the measurement range and of
the protection against special conditions such as vibrations, pulsations and pressure spikes.
A bracket must be installed to support the switch if the metering pipe is not able to provide adequate support.
Ambient Temperature: –20 to 60°C
Process Temperature: –20 to 60°C, other temperature limits are possible with different diaphragm materials
Refer to appropriate datasheet for materials of construction and technical information.
These controls are precision instruments and should never be left with internal components exposed. During
installation insure that covers are in place and conduit openings are closed except when actually working on the
control.
To minimize the risk of injury, the control must be installed according to the required safety and electrical codes.
To attain the degree of protection listed on the switch it may be necessary to add required conduit fittings.
The switch must be protected from moisture, shock and/or extreme vibration.
Mounting position: Switch can be mounted in any position. It is recommended that unit be set in intended
operating position.
Cautions:
Always install the cover after wiring the switch and before power is supplied.
Before removing the cover in hazardous areas be sure there is no explosive atmosphere present and the power
supply is turned off.
For ATEX approved switches all safety locking devices and electrical earthing must be installed or connected
before operating.
Never carry a temperature switch by holding only the stem, bulb or capillary.
Do not push any foreign objects (ex. Screwdrivers) against the diaphragm.
Do not exceed ranges, current and/or voltage limits.

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8.3 Mounting/Installation
8.3.1 Process connection
As standard, the device is equipped for pipework mounting with a pressure connection shank pursuant to DIN EN 837-
3. The device is calibrated ex works for vertical installation.
Connection to be undertaken by authorized and qualified specialist staff only.
Three holes external to the enclosure for surface mounting. Location of these holes is shown in the general
dimension drawing.
Units may also be mounted directly on the pressure line using the pressure connection.
Use only with the mechanical process connection provided – regarding the configuration, see order code on the
device type label, with a matching threaded seal.
When connecting the device, the pipes must be depressurized.
The pressure metering pipe must be laid inclined in such a way that, for example, for measurements of fluids no
air pockets can form, and for measurements of gases no water pockets. If the necessary incline is not achieved,
then at suitable points water separators or air separators must be installed.
The pressure metering pipe must be kept as short as possible and laid without sharp bends, to avoid the
occurrence of irritating delays.
With liquid measurement media, the pressurized connection pipe must be degassed, since any gas bubble
inclusions result in measurement error.
If water is used as the measurement medium, the device must be frost-protected.
Safety notice: When tightening control to pressure line, always use the wrench flats or hex on the lower
housing, and do not twist the device itself.
8.3.2 Electrical connection
Take note of the electrical data in the EU design type test certification and the locally-applicable regulations
and guidelines for installing and operating electrical plant in explosion risk areas (e.g. EN 60079-14, etc.).
Connection to be undertaken by authorized and qualified specialist staff only.
The electrical connection of the device is to be undertaken in accordance with the relevant regulations of the VDE
and the regulations supplied by the local utilities company.
Disconnect the plant from the mains supply before wiring electrical connections.
Before operating the switch all conduit entries and/or junction boxes need to be closed according to the required
safety and electrical codes.
a) Standard product has two 3⁄4 NPT conduit holes with one permanent plug. 3⁄4 NPT conduit holes can be
modified or reduced with ATEX approved adapters.
b) Available ATEX approved cable glands can be used.
It is recommended that Teflon tape or other sealant be used on conduit, bushing, gland or plug threads to ensure
integrity of the enclosure.
Cable couplers, glands and conduit connectors must have the correct electrical approvals.
Always follow safety and electrical regulations when connecting these devices.
The system ground of the device is marked with a green colored screw and/or by the ground symbol.
ATEX approved switches have an external ground screw that must be connected..

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NO (Normally Open) Blue
NC (Normally Closed) Red
C (Common) White
Figure 2: Micro switch terminals and wire color codes
SPDT – Wire directly to the switch according to circuit requirements.
2 SPDT – Wire to front switch terminal block (left) and rear switch terminal block (right) as marked. Strip insulation
5⁄16˝, insert in proper terminal connector and tighten clamping screw to secure.
8.4 Starting up and setpoint adjustment
The precondition for start-up is proper installation of all electrical feed lines and metering pipes. All connecting lines
must be laid such that no mechanical forces can act on the device.
Before start-up, the seal on the pressurized connection line must be checked.
Note – As indicated below, adjustment of setpoint is made by use of 7⁄8˝ nut. Precision switch element
mounting screws and bracket adjusting screw are factory sealed and should not be tampered with.
8.4.1 Pressure switch model B7
A single setpoint adjustment nut (7/8”) is located centrally at the bottom on the inside of the enclosure.
For accurate setpoint calibration, mount the switch on a calibration stand, a pump or catalog No. 1305 deadweight
gauge tester. A suitable reference standard such as an ASHCROFT Duragauge or Test Gauge is necessary to
observe convenient changes in pressure.
As received, the pressure switch will normally be set to approximately 90% of the indicated range. Pressurize the
system to required setpoint and turn the adjustment nut until switch changes mode. Direction of turning is indicated on
a label affixed to the inside of the control enclosure. When setpoint has been achieved raise and lower pressure to
insure that setpoint is correct.
After installation of the control replace cover to insure electrical safety and to protect internal parts from the
environment.
Note – Since vacuum models are already above setpoint at atmosphere, the Normally Open (NO) circuit will
be closed as received.
.
8.4.2 Differential pressure switch model D7 (high range)
A single setpoint adjustment nut (7⁄8˝) is located centrally at the bottom on the inside of the enclosure.
The direction of turning is indicated on a label affixed to the inside of the control enclosure.
A typical calibration procedure would be as follows:
Static Working Pressure - 600 psig
Adjustable Differential Range - 5/200 psid
Differential Setpoint - 150 psi above static working pressure.
Simultaneously raise the high and low side pressure to 600 psig. Maintain the low side pressure at 600 psig. Raise the
high side pressure to 750 psig to obtain 150 psi differential.
Turn the adjustment nut until the switch changes mode at 150 psi differential. When the setpoint has been achieved,
raise and lower the high side pressure to ensure that the differential setpoint is correct.

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After installation of the control replace cover to insure electrical safety and to protect internal parts from the
environment.
8.4.3 Differential pressure switch model D7 (low range)
A single setpoint adjustment nut (7⁄8˝) is located centrally at the bottom on the inside of the enclosure.
The direction of turning is indicated on a label affixed to the inside of the control enclosure. XG5 controls have a
setpoint indication scale adjacent to the adjustment nut. To adjust the control, align the top of the adjustment nut hex
with the indicator line on the scale. Do not force adjustment or attempt to exceed the maximum setting shown on the
scale or nameplate.
For accurate setpoint calibration or for controls without a scale mount the control on a calibration stand so that the
HIGH and LOW pressures expected under operating conditions may be obtained. Suitable reference standards are
necessary for each pressure.
Note – Due to the sensitivity of these controls it is imperative that the LOW pressure side volume be large
to prevent a setpoint shift between calibration and field installation. If this is not possible, an approximate
setpoint under operating conditions can be obtained by setting the operating point with the low side open to
atmosphere. A final setpoint adjustment can be made after installation.
Apply LOW pressure. Then apply HIGH pressure to the required setpoint and turn the adjustment nut until the switch
operates. When the setpoint has been achieved, raise and lower HIGH pressure to ensure that the differential
pressure between the HIGH and LOW pressures is correct.
After installation of the control, replace the cover to ensure electrical safety and to protect the internal parts from the
environment.
8.4.4 Temperature switch model T7
A single setpoint adjustment nut (7⁄8˝) is located centrally at the bottom on the inside of the enclosure.
The bulb of the control should be immersed in a bath at the desired setpoint temperature. Optimum performance will
be obtained if the bulb is fully immersed. Allow five minutes for initial stabilization.
As received, the temperature switch will normally be set to approximately 90% of the indicated range. After
stabilization, turn the adjustment nut until switch changes mode. Direction of turning is indicated on a label affixed to
the inside of the control enclosure. When setpoint has been achieved raise and lower temperature to insure that the
setpoint is correct.
After installation of the control replace cover to insure electrical safety and to protect internal parts from the
environment.
8.4.5 B750, D750 and T750 Variable Deadband Switches
Deadband is varied by rotating the wheel on the precision switch. When viewed from the front of the enclosure,
rotation to the left increases deadband – rotation to the right decreases deadband. Letters on the wheel may be used
as a reference. Deadbands obtainable will vary from 0.5% to 9% of pressure or temperature range depending on
range segment and type of diaphragm.
Adjustment of Setpoint – As received, the switch will normally be set to approximately 90% of range. Rotate the wheel
on the MICRO SWITCH all the way to the right; this will provide smallest deadband. Pressurize, or increase bath
temperature, to the required setpoint and turn the adjustment nut until the switch changes mode. Lower the pressure
to reset the switch. Rotate the wheel on the MICRO SWITCH until the desired deadband is obtained. The upper
setpoint will be changing upward with this adjustment. Lower the pressure to reset the switch. Then increase the
pressure to the desired setpoint and turn the adjusting nut until the switch changes mode. Lower the pressure and
check resetpoint and deadband.
8.5 Subsequent relocation of the switch (by the customer)
Recommendation: Do not remove the switch from one metering point and fit it in a different place, as
there is a risk of the measuring media being mixed, with unforeseeable chemical reactions.
9 Servicing
All ASHCROFT switches require little or no maintenance.
Be sure that the case is closed at all times.

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When the switch is exposed to process media that may harden and/or build up in the pressure port, the switch
should be removed and cleaned as needed.
However, to ensure reliable operation and a long lifetime for the device, we recommend that it is checked regularly.
9.1 Safety
When undertaking servicing work on the device, the pressure lines must be depressurized, the electrical connections
isolated from the mains supply, and the plant secured against being switched on again.
9.2 Check on function, and recalibration
The check on function and recalibration is carried out at regular intervals, depending on the application. The precise
testing cycles should be adjusted in line with the operating conditions and ambient conditions. In the event of various
device components interacting, the operating instructions for all other devices should also be taken into account.
Check on function, in conjunction with downstream components.
Check of pressurized connection pipes for seal condition.
Check of electrical connections.
9.3 Cleaning and maintenance
Never use aggressive solvents.
Do not use high-pressure water to clean the switch.
10 Faults
10.1 Safety
Defective or faulty switches put the operational safety and process safety of the plant at risk, and can lead to a risk or
injury to persons, the environment or the plant.
10.2 Conduct in the event of faults
All defective of faulty devices must be taken out of service. If a repair is required, the device must be sent directly to
our Repairs Department. We request that all returns of devices are agreed with our Service Department.
10.3 Fault table
Possible situations indicating a fault:
Setpoint shift or deadband out of range
Random switch function
Corrosion at process connection and diaphragm
Leakage of process media
Bended stem or bulb
Sharp edged bended capillary line
Damage to housing or wiring
In these instances, replacement of the switch is always required.
10.4 Conduct following fault rectification
See Chapter 8.3 Mounting/Installation
11 Removal, disposal
11.1 Safety
Residues of measuring media in and on removed switches can constitute a risk to people, the environment
and equipment. Adequate precautionary measures must be adopted. If necessary, the devices must be
cleaned thoroughly (see advice in safety data sheets).
11.2 Removal

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When undertaking servicing work on the device, the pressure lines must be depressurized, the electrical
connections isolated from the mains supply, and the plant secured against being switched on again.
Demount the switch using a suitable tool
11.3 Disposal
Please help to protect the environment and dispose of or recycle the devices and components used in
accordance with the applicable regulations.
12 Appendix
12.1 Data sheet for switches B7, D7 and T7
More detailed datasheets are available direct from the manufacturer (see 1.6 Manufacturer’s address, customer
services).
The table below contains an overview of the individual documents.
Model
Description
Document
B7
Pressure switch series B4 and B7
G4.SW20-P
D7
Differential pressure switch series D4 and D7
G4.SW20-P
T7
Temperature switch series T4 and T7
G4.SW20-T

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12.2 EG Declaration of Conformity

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12.3 IECEX Declaration of conformity

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