PKP DS52 User manual

Instruction Manual
DS52
Low Cost Variable Area Flow Switch
PKP Prozessmesstechnik GmbH
Borsigstraße 24
D-65205 Wiesbaden- ordenstadt
Tel.: ++49-(0)6122-7055-0
Fax: ++49-(0)6122-7055-50
Email: [e-mail]

Table of Contents
Safety Information..................................................................................................................2
Functional Description...........................................................................................................3
Installation and Commissioning.............................................................................................4
Electrical Connection.............................................................................................................5
Adjustment of the switching point..........................................................................................6
Maintenance and Care...........................................................................................................7
Troubleshooting.....................................................................................................................8
Safety Information
General Instructions
To ensure safe operation, the device should only be operated according to the specifica -
tions in the instruction manual. The requisite Health & Safety regulations for a given appli -
cation must also be observed. This statement also applies to the use of accessories.
Every person who is commissioned with the initiation or operation of this device must have
read and understood the operating instructions and in particular the safety instructions!
The liability of the manufacturer expires in the event of damage due to improper use, non-
observance of this operating manual, use of insufficiently qualified personnel and unau-
thorized modification of the device.
roper Usage
The devices of the DS52 series are used to monitor the continuous flow of liquids or
gases. Any other use is considered improper. Unless otherwise stated, the scales of the
devices refer to water or air at 1.013 bar abs. and 20 °C.
In particular, applications in which shock loads occur (e.g. clocked operation) should be
discussed and checked beforehand with our technical personnel.
The devices of the DS52 series must not be used as the sole means of preventing dan -
gerous conditions on machines and systems.
Machines and systems must be designed in such a way that faulty conditions cannot lead
to a dangerous situation for the operating personnel.
Dangerous substances
For dangerous media such as e.g. Oxygen, Acetylene, flammable or toxic substances as
well as refrigeration systems, compressors, etc. must comply with the relevant regulations
beyond the general rules.
DS52 Instruction manual 02/2019 page 2

Qualified ersonnel
The DS52 devices may only be installed by trained, qualified personnel who are able to
mount the devices correctly. Qualified personnel are persons, who are familiar with
assembling, installation, placing in service and operating these devices and who are suit-
ably trained and qualified.
Inward Monitoring
Please check directly after delivery the device for any transport damages and deficiencies.
Additional with reference to the accompanying delivery note the number of parts must be
checked.
Claims for replacement or goods which relate to transport damage can only be considered
valid if the delivery company is notified without delay.
Functional Description
The devices of the DS52 series operate according to the principle of the variable area flow
meter. A float is moved by the flow of the medium and its integrated magnets generate a
magnetic field. The position of the float is determined by the switching contact. The float is
returned to its initial position by a spring, so that the device can also be operated in other
installation positions (e.g. horizontal).
The devices are calibrated for installation with flow from bottom to top and have their
greatest accuracy with vertical installation. Since the weight of the float influences the
measurement result, deviations occur in other installation positions.
DS52 Instruction manual 02/2019 page 3

Installation and Commissioning
rocess Connection
Attention:
The following requirements must be met in order to avoid damage to the flow monitor or
the system.
•A process connection suitable for the device must be provided by the customer.
•Check connection size and screw-in depth
•Use suitable sealants (liquid sealants damage the flow monitor when they enter)
•Professional sealing
Environmental Conditions
•The flow monitor must not be used as a load-bearing part in pipe constructions.
•The medium must not carry any solid bodies. Magnetic particles accumulate on the
magnetic float and impair its function.
•Check corrosion and antifreeze agents for compatibility before use.
Attention:
The following requirements must be met, otherwise the function of the flow monitor will be
impaired or measurement results will be falsified.
•External magnetic fields influence the switching contact. Keep sufficient distance to
magnetic fields (e.g. electric motors).
•Pipes, process connections or brackets made of ferromagnetic material influence
the magnetic field of the flow monitor. Keep a distance of 100mm to such materials
(e.g. steel).
•Changes in cross-section, branches or bends in the pipelines influence the measur-
ing accuracy. In front of the device, a calming section of
•10 x D , 5 x D behind the device. ever reduce the pipe diameter directly in front
of the unit!
•In the case of liquid media, take suitable measures to ensure that the device is
vented.
DS52 Instruction manual 02/2019 page 4

Electrical Connection
Attention:
Before the electrical connection of the device, it must be ensured that the supply voltage
corresponds to the required one and that the supply voltage is switched off.
The switching contacts used in the devices are potential-free and do not require any
power supply.
Attention:
Switching contact and device are matched to each other. After a switching contact has
been replaced, it must be readjusted.
Please ask for the corresponding assembly instructions.
Condition of the contact with device without flow rate:
Wiring diagram: N/O
Wiring diagram: SPDT
Standard Switching Contact
Connection diagram of the supplied socket (DI 43650 Form A or C).
The earth connection is not used.
Important note:
Protection cla IP65 when u ing the DIN 43650 plug ocket i only guaranteed in
conjunction with cable diameter of 6 - 8 mm.
Switch contact with cable
The wires of the connection cable are numbered according to the above connection dia -
gram.
DS52 Instruction manual 02/2019 page 5

Special Designs
On request, switching contacts can be supplied in special designs (plug, pre-assembled
cable).
EEx-tested switching contacts
Attention:
Special regulations apply to the connection of EEx-tested switching units, which must be
strictly observed! Observe the instructions in the separate operating instructions for EEx-
tested switching contacts!
Contact rotection Measures
Attention:
The following requirements must be met, otherwise the switching contact will be
destroyed.
The reed contacts used in the switching contacts are very sensitive to overload due to
their design. one of the values such as voltage, current or power may be exceeded even
for a short time.
There is a risk of overload due to:
•inductive loads
•capacitive loads
•resistive loads
Inductive Load :
This type of load is caused, for example, by:
•contactors, relays
•magnetic valves
•electric motors
Adjustment of the switching point
•Loosen the locking screw of the switching contact.
•Move the switching contact until the arrow on the switching contact coincides with
the desired switching point.
•Retighten the locking screw of the switch contact.
Important:
•The set switching point corresponds to the switch-off point of the switching contact
with falling flow rate.
•The current state of the switching contact can be determined e.g. with a continuity
tester.
•The states of the switching contact refer to the normally open contact ( /O).
DS52 Instruction manual 02/2019 page 6

Maintenance and Care
Due to the small number of moving parts, the devices require very little maintenance.
However, regular functional checks and maintenance not only increase the service life and
functional reliability of the device, but also that of the entire system.
The maintenance intervals depend on:
•contamination of the medium
•environment conditions (e.g. vibrations)
At least the following points must be checked during maintenance:
•Function of the switching contact
•Tightness of the device
•Mobility of the float
Depending on the application, it is the responsibility of the operator to determine suitable
maintenance intervals.
Important:
•The float motion and the switching contact function can be checked by changing
the flow rate and monitoring the switching state of the switching contact.
•In most cases, rinsing with a clean medium is sufficient for cleaning. In stubborn
cases (e.g. limescale deposits), it can be cleaned with commercially available
cleaners, provided these do not attack the materials of the device.
Attention: Opening the device voids the warranty claim!
DS52 Instruction manual 02/2019 page 7

Troubleshooting
The switching contact does not switch:
The witching contact i alway in the idle tate
1. o flow
•Check whether medium is actually flowing
2. Flow too low or switching contact set too high
•Set the switching contact to lower flow rate
•Using a device with a different measuring range
3. Incorrectly reduced (conductor cross-section too small)
•Reduce according to "Installation and Commissioning”
4. Float jams (dirt)
•Clean the unit and make the float passable.
5. Switching contact defective
•Eliminate the cause of the defect (short circuit, overload)
•Replace the switching contact, see "Electrical connection"
The witching contact i permanently witched
1. Flow too high or switching contact set too low
•Reduce the flow rate
•Set the switch contact to a higher flow rate.
2. Float jams (dirt)
•Clean the unit and make the float passable.
3. Switching contact defective defekt
•Eliminate the cause of the defect (short circuit, overload)
•Replace the switching contact, see "Electrical connection"
The witching point doe not corre pond to the actual flow rate
1. o media-specific scale
•Request a conversion table or a media specific scale
2. Incorrectly reduced
•Reduce according to "Installation and Commissioning”
3. Device dirty
•Clean the unit
4. Device defective
•Return the instrument for repair / calibration
DS52 Instruction manual 02/2019 page 8

Connecting devices equipped with Reed switches
Reed switches are basically designed for small contact ratings. To connect a load with higher power
consumption it is indispensable to use a contact protection relay (e.g. our series MSR01)
If you connect directly a load to a Reed contact the following recommendations should be considered.
one of the contact rating values printed on the switching unit must not to be exceeded, even
momentarily. This is valid for each of the given values individually: voltage, current, power. The Reed
contact integrated in the switching unit is very sensible to electrical overload
Danger of overload is given by the following applications:
•inductive load
•capacitive load
•lamp load
Inductive Load
Inductive loads consist e.g. of relay, contactors, solenoid valves, motors, electric engines, etc.
WAR I G: Voltage spikes at shut down (up to 10 times of nominal voltage)
Protective measures: (examples)
(Flyback diode, e.g. type 1 4007)
Capacitive Load
Capacitive loads consist e.g. of long connection cables or capacitive consumers.
WAR I G: High current spikes at switching on (this will exceed the nominal current)
Protective measures: (examples)
Limitation of current by a resistor
Lamp Load
Lamp loads consist e.g. by light bulbs, starting motors .
WAR I G: High current spikes at switching on, because the glowing spiral has low resistance at
low temperature.
Protective measures: (examples)
Limitation of current by a resistor or
preheating of the glowing spiral.

Connecting to a PLC
There is no need for protective measures by connecting the Reed switch to a PLC. The Reed contacts
are plated by Tunsten, Gold, and Rhodium located in a protective atmosphere. They can be directly
connected to the input terminals of a PLC without problems.
RC-Circuits as protective measures (Boucherot cell, Snubber
In practice the following values of resistor/capacitor cells give good results. evertheless, the values
given in the following tables are only recommendations for general purposes. But it cannot be
guaranteed that for specific applications more adequate Boucherot cells may exist.
For Reed switches of 10 – 40 VA
Voltage [V] Resistance [Ohm] Capacitance [nF]
230 1500 330
115 470 330
48 220 330
24 100 330
For Reed switches of 40 – 100 VA
Voltage [V] Resistance [Ohm] Capacitance [nF]
230 1000 330
115 470 330
48 100 330
24 47 330