Sentera Controls DPS-M-LP Service manual

DPS-M--LP DIFFERENTIAL PRESSURE
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Mounting and operating instructions

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DPS-M--LP DIFFERENTIAL PRESSURE
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Table of contents
SAFETY AND PRECAUTIONS 3
PRODUCT DESCRIPTION 4
ARTICLE CODE 4
INTENDED AREA OF USE 4
TECHNICAL DATA 4
STANDARDS 4
OPERATIONAL DIAGRAMS 5
WIRING AND CONNECTIONS 5
MOUNTING INSTRUCTIONS IN STEPS 5
VERIFICATION OF INSTALLATION 7
OPERATING INSTRUCTIONS 8
TRANSPORT AND STORAGE 11
WARRANTY AND RESTRICTIONS 11
MAINTENANCE 11

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DPS-M--LP DIFFERENTIAL PRESSURE
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SAFETY AND PRECAUTIONS
Read all the information, the datasheet, Modbus map, mounting and operating
instructions and study the wiring and connection diagram before working with the
product. For personal and equipment safety, and for optimum product performance,
make sure you entirely understand the contents before installing, using, or maintaining
this product.
For safety and licensing (CE) reasons, unauthorised conversion and/ or modifications
of the product are inadmissible.
e product should not be exposed to abnormal conditions, such as extreme
temperatures, direct sunlight or vibrations. Long-term exposure to chemical
vapours in high concentration can affect the product performance. Make sure the
work environment is as dry as possible; avoid condensation.
All installations shall comply with local health and safety regulations and local
electrical standards and approved codes. is product can only be installed by
an engineer or a technician who has expert knowledge of the product and safety
precautions.
Avoid contacts with energised electrical parts. Always disconnect the power
supply before connecting, servicing or repairing the product.
Always verify that you apply appropriate power supply to the product and use
appropriate wire size and characteristics. Make sure that all the screws and nuts
are well tightened and fuses (if any) are fitted well.
Recycling of equipment and packaging should be taken into consideration and these
should be disposed of in accordance with local and national legislation/regulations.
In case there are any questions that are not answered, please contact your
technical support or consult a professional.

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DPS-M--LP DIFFERENTIAL PRESSURE
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PRODUCT DESCRIPTION
e DPS-М--LP series are differential pressure transmitters (-125—125 Pa), which
are equipped with a fully digital pressure transducer designed for a wide range of
applications. Air velocity readout is available by connecting an external Pitot tube
connection set. ey are Power over Modbus supplied and parameters are accessible
via Modbus RTU (3SModbus software or Sensistant).
ARTICLE CODE
Codes Power supply Connection Imax Operating range
DPS-М--LP 24 VDC, Power over Modbus RJ45 connector on the PCB 100 mA -125—125 Pa
INTENDED AREA OF USE
■Differential pressure, air velocity or volume flow measurement in HVAC applications
■Overpressurizing applications: clean rooms to avoid particle contamination or
staircases for fire safety
■Underpressurizing applications: restaurant kitchens and biohazard laboratories
■Volume flow application: ensuring the minimum legal ventilation rate (m3/h) for
buildings
TECHNICAL DATA
■4-digit 7-segment LED display for indicating differential pressure or air volume
flow
■Built-in digital high resolution differential pressure sensor
■Minimum differential pressure range span: 5 Pa
■Minimum volume flow range span: 10 m3/h
■Minimum air velocity range span: 1 m/s
■Selectable response time: 0,1—10 s
■Implemented K-factor
■Differential pressure, air volume or air velocity readout via Modbus RTU
■Air velocity can be measured via Modbus RTU (by using an external PSET-PTX-200
Pitot tube connection set)
■Selectable minimum and maximum operating ranges
■Modbus registers reset function (to factory pre-set values)
■Four LEDs for transmitter status indication
■Modbus RTU communication
■Sensor calibration procedure via tactile switch
■Aluminium pressure connection nozzles
■Accuracy: ±2 % of the operating range
■Operating ambient conditions:
►Temperature: -5—65 °C
►Rel. humidity: < 95 % rH (non-condensing)
■Storage temperature: -20—70 °C
STANDARDS
■EMC Directive 2014/30/EC:
►EN 61326-1:2013 Electrical equipment for measurement, control and
laboratory use - EMC requirements - Part 1: General requirements
►EN 61326-2-3:2013 Electrical equipment for measurement, control and
laboratory use - EMC requirements - Part 2-3: Particular requirements - Test
configuration, operational conditions and performance criteria for transducers
with integrated or remote signal conditioning

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DPS-M--LP DIFFERENTIAL PRESSURE
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■WEEE Direc tive 2012/19/EC
■RoHs Directive 2011/65/EC
OPERATIONAL DIAGRAMS
10
20
30
40
50
60
70
80
90
100
Minimum
range
Output [%]
Measured value (pressure, volume flow or air velocity) vs. output
Minimum
alert
Maximum
alert
Maximum
range
Differential pressure
Volume flow
Air velocity
Out of range LED4 ON
Within range LED2 ON
Alert LED3 ON
Alert LED3 ON
Out of range LED4 ON
WIRING AND CONNECTIONS
RJ45 socket (Power over Modbus)
Pin 1 24 VDC Supply voltage
Pin 2
Pin 3 AModbus RTU communication, signal A
Pin 4
Pin 5 /B Modbus RTU communication, signal /B
Pin 6
Pin 7 GND Ground, supply voltage
Pin 8
/B
A
GND
24 VDC
8 mm
8 mm
8 mm
8 mm
RJ45
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
3
4
5
6
3
4
MOUNTING INSTRUCTIONS IN STEPS
Before you start mounting the unit, read carefully “Safety and Precautions”.
Choose a smooth surface for installation (awall, panel, etc.) and follow these steps:
1. Unscrew the front cover of the enclosure to remove it.
2. Fix the enclosure onto the surface by means of suitable fasteners while adhering
to the mounting dimensions shown in Fig. 1 and the correct mounting position
shown in Fig. 2 below.

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DPS-M--LP DIFFERENTIAL PRESSURE
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Fig. 1 Mounting dimensions Fig. 2 Mounting position
46
24 15 10,5
2x Ø 3,
4
49
52
Correct Incorrect
DPS
+_
DPS
+_
DPS
+_
3. Insert the cable into the cable gland.
4. Crimp the RJ45 cable and plug it into the socket, see Fig.3 and section “Wiring
and connections”.
Fig. 3 Connections
5. Connect the nozzles to the duct (see Fig. 4). Depending the application you must
use a specific connection set to connect the nozzles of the unit to the duct:
5.1 To measure differential pressure, use PSET-QF or PSET-PVC set (pressure
measurement is the unit default setting);
5.2 To measure volume flow, use PSET-PT Pitot tube connection set, PSET-
QF or PSET-PVC connection set. If you use PSET-PT, you should enter the
duct cross sectional area [cm²] in Modbus register 63. If you use PSET-QF
or PSET-PVC, enter the K-factor of the fan (provided by the fan /motor
manufacturer) in Modbus holding register 62.
In case the K-factor is not known, volume flow is calculated from a duct
cross sectional area (holding register 63) multiplied by air velocity (Pitot air
velocity (holding register 64) should be enabled and Pitot tube connected).
5.3 To measure air velocity, use PSET-PT set and enable Pitot tube air velocity
via holding register 64. In this case the K-factor of the fan has to be 0

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DPS-M--LP DIFFERENTIAL PRESSURE
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Fig. 4 Connecting with accessories
Application 1: Measuring differential pressure [Pa] or
volume flow [m³/h] using PSET-PVC (or PSET-QF)
Application 2: Measuring volume flow [m³/h] or air velocity
[m/s] using PSET-PT
DPS
+_
+D -S
DPS
+_
6. Switch on the power supply.
Optional settings
To assure correct communication, the NBT needs to be activated in only two devices
on the Modbus RTU network. If necessary, enable the NBT resistor via 3SModbus or
Sensistant (Holding register 9).
Example 1 Example 2
RX
ТX
NBT
NBT
Slave 2
Master
Slave n
Slave 1
Slave 2
Slave 1
RX
ТX
NBT
NBT
Master
Slave n
NOTE On a Modbus RTU network, two bus terminators (NBTs) need to be activated.
7. Put back the front cover and secure it with the screws.
8. Customise the factory settings to the desired ones via the 3SModbus software
or the Sensistant configurator. For the default factory settings, see Modbus
register map.
For the complete Modbus register data, refer to the product Modbus Register
Map, which is a separate document attached to the article code on the website
and contains the registers list. Products with earlier firmware versions may not be
compatible with this list.
NOTE
VERIFICATION OF INSTALLATION
A continuous green LED1 indication as shown in Fig. 7 Power / Modbus communication
indication means the unit is powered. If LED1 is not on, check the connections again.
A blinking green LED1 indication as shown in Fig. 7 Power / Modbus communication

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DPS-M--LP DIFFERENTIAL PRESSURE
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indication means the unit has detected a Modbus network. If LED1 does not blink,
check the connections again.
NOTE For more information, refer to the product datasheet - Settings.
Fig. 7 Power / Modbus communication indication
ATTENTION e status of the LEDs can be checked only when the unit is energised. Take the
relevant safety measures!
ATTENTION LED intensity can be adjusted between 0 and 100 % with a step of 10 % according
to the value set in Holding register 95.
NOTE For sensor calibration and Modbus registers reset procedures, refer to section
“Operating instructions”.
OPERATING INSTRUCTIONS
NOTE For detailed information and settings, refer to the product Modbus register map,
which is attached to the article code on our website.
Calibration procedure:
1. Disconnect the nozzles and make sure they are not clogged.
2. ere are two options for starting the calibration process:
Either write “1” in holding register 70 or press button SW1 for 4 seconds until the
green LED2 and yellow LED3 on the printed circuit board blink twice and release it
immediately. If you hold SW1 for too long, you will reset the Modbus registers! (see
Fig.8Sensor calibration and Modbus register reset).
3. After 2 seconds the green LED2 and yellow LED3 will blink twice once again
to indicate that the calibration procedure has finished (see Fig. 9 a Calibration
Indication).
ATTENTION Make sure that the nozzles are disconnected and unobstructed.
Reset of Modbus registers procedure:
1. Press tact switch SW1 for 4 seconds until the green LED2 and yellow LED3 on the
printed circuit board blink twice and hold the switch until both LEDs blink again three
times (see Fig. 8 Sensor calibration and Modbus register reset ).
2. e Modbus registers are reset to their default values (factory pre-set).
3. During the Modbus reset procedure the display will indicate “H” (See Fig. 9 b
Modbus reset indication).

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DPS-M--LP DIFFERENTIAL PRESSURE
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Fig. 8 Sensor calibration and Modbus register
reset Fig. 9 Calibration & Modbus reset indication
SW1
LED1
LED2
LED3
LED4
9 a Calibration indication 9 b Modbus reset indication
Communication holding registers reset procedure:
1. Put the jumper onto pins 1 and 2 of the P4 connector for more than 20 s while
the device is powered (see Fig. 10 ).
Fig. 10 Modbus holding register reset jumper
1
2
3
4
5
2. Modbus communication holding registers from 1 to 3 will be reset to the default
values.
3. Remove the jumper.
ATTENTION Correct reading of air velocity is only possible if it is enabled by holding register
64 (Pitot air velocity) and a transmitter is connected to the appropriate Pitot tube
connection set (PSET-PTX-200).
Display settings
e display is enabled via writing “1” in holding register 91 (Measurement readout).
Writing “0” will disable the display.
When the display is enabled, its mode depends on the value in holding register 61
(Operating mode). ere are three display modes activated via writing the relevant
figure in holding register 61 - see the table below:
Measurement readout enabled
Value of holding register 61: Display mode:
1 Differential pressure
2Volume flow rate
3Air velocity
1. Differential pressure display mode (see Fig. 11):
1.1 e LED display indicates the differential pressure level with a resolution of
0,1 Pa if the level is below 100 Pa. However, above 100 Pa, the resolution
is 1 Pa. In both cases the 3SModbus software indicates the actual value.
See Fig. 11 below.

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DPS-M--LP DIFFERENTIAL PRESSURE
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Fig. 11 Differential pressure display
11 a Below 100 Pa 11 b Above 100 Pa
1.2 Out of range indication:
►e display shows “Lo” every 3 seconds in case the measured differential
pressure is lower than the minimum limit of the control range set via the
relevant holding register (see Fig. 12 a).
►In case the measured differential pressure is higher than the control range
maximum limit, the display shows ‘HI’ every 3 seconds (see Fig. 12 b) .
Fig. 12 Out of range indication
12 a Below control range minimum limit 12 b Above control range maximum limit
2. Air volume flow display mode:
2.1 Air volume flow rate within the range 0—9999 m3/h is displayed with
a resolution of 1 m3/h. An example of displaying 100 m3/h is given in
Fig. 13 a below.
2.2 Air volume flow rate above 10.000 m3/h is displayed divided by 1.000. An
example of displaying 10.000 m3/h is given in Fig. 13 b below.
Fig. 13 Air volume flow and air velocity mode indications
13 a Air volume flow mode (0—9999 m3/h) 13 b Air volume flow mode (10.000 m3/h)
3. Air velocity display mode:
3.1 Air velocity is displayed with a resolution of 0,1 m/s. An example of displaying
1,0 m/s is given in Fig. 14 below.