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Copyright HK Instruments 2019

www.hkinstruments.fi

Installation version 7.0 2019

INSTALLATION

INSTRUCTIONS

DIFFERENTIAL PRESSURE SWITCHES 

DPI Series

•  READ THESE INSTRUCTIONS CAREFULLY BEFORE 

ATTEMPTING TO INSTALL, OPERATE OR SERVICE THIS 
DEVICE.

•  Failure to observe safety information and comply with 

instructions can result in PERSONAL INJURY, DEATH AND/OR 

PROPERTY DAMAGE.

•  To avoid electrical shock or damage to equipment, disconnect 

power before installing or servicing and use only wiring with 
insulation rated for full device operating voltage.

•  To avoid potential fire and/or explosion do not use in potentially 

flammable or explosive atmospheres.

•  Retain these instructions for future reference.
•  This product, when installed, will be part of an engineered 

system whose specifications and performance characteristics 
are not designed or controlled by HK Instruments. Review 
applications and national and local codes to assure that the 
installation will be functional and safe. Use only experienced and 
knowledgeable technicians to install this device.

SPECIFICATIONS

Thank you for choosing an HK Instruments DPI series electronic dif

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ferential pressure switch. The DPI series is intended for use in com

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mercial environments. It combines the advantages of an electronic 
differential  pressure  switch  (on-off  relay)  and  a  multi-functional 
differential  pressure  transmitter  to  meet  your  application  require

-

ments.

The  DPI  series  is  comprised  of  the  DPI±500  with  bi-directional 
measurement ranges from ±100 to ±500 Pa and the DPI2500 with 
measurement ranges from 100 to 2500 Pa.

All DPI series devices include one relay, display, manual pushbutton 
zero point calibration and span point calibration. Optional features 
include a second relay and autozero calibration.

DPI series devices are commonly used in HVAC/R systems for:
• fan, blower and filter monitoring
• staircase pressure monitoring and alarm
• pressure monitoring in cleanrooms
• boiler pressure monitoring and alarm

SPECIFICATIONS

Performance

Accuracy:

±1.5 % (±0.7 %*)

%FS from highest pressure range (including:

general accuracy, temperature drift, linearity, hysteresis,

and repetition error)

*Can be achieved with span point calibration

Long term stability:

Typical 1 year

With autozero:  ±1 Pa

Without autozero:  ±8 Pa

Thermal effects:

Temperature compensated across the full spectrum of

capability

Overpressure:

Proof pressure: 25 kPa

Burst pressure: 30 kPa

Zero point calibration:

Automatic with autozero (-AZ) circuit or

Manual via menu

Response time:

0.5–10 s, selectable via menu

Technical Specifications

Media compatibility:

Dry air or non-aggressive gases

Measuring units:

Pa, kPa, mmWC, inWC, mbar selectable via menu

Measuring element:

Piezoresistive

Environment:

Operating Temperature:

 

Without autozero : -10...50 °C

 

With autozero: -5...50 °C

Storage temperature: -20...70 °C

Humidity: 0 to 95 % rH, non condensing

Physical

Dimensions:

Case: 89 x 86.5 x 37.1 mm

Weight: 

150 g

Mounting:  

Case: 2 each 4.3 mm holes

Lid: 2 each 4.3 mm holes

Materials:  

Case: ABS

Lid: PC

Duct connectors: ABS

Tubing: PVC

Protection standard: 

IP54 

Touch sensitive buttons on the lid:

Menu, Back, OK, down arrow, up arrow

Display:

3 1/2 digit LCD backlit display

Size: 46.0 W x 14.5 H mm

Electrical connections:

n/out:

 

Terminal block (24 V, GND, 0–10 V)

 

Wire: 0.2–1.5 mm

2

 (12–24 AWG)

Relay 1:

 

Terminal block (NC, COM, NO)

 

Wire: 0.2–1.5 mm

2

 (12–24 AWG)

Relay 2:

 

Terminal block (NC, COM, NO)

 

Wire: 0.2–1.5 mm

2

 (12–24 AWG)

Cable entries:

Strain relief: M16 & M20

Knockout : 16 mm

Knockout : 20 mm

Pressure fittings:

5.2 mm barbed brass

 

+ High pressure

 

− Low pressure

Electrical

Circuit: 3-wire (24 V, GND, 0–10 V)

Input:

 

Without autozero: 21–35 VDC/ 24 VAC, ±10 %

 

With autozero: 24 VAC or VDC, ±10 %

Output:

 

Analog: 0–10 V

 

Relay 1: 250 VAC / 30 VDC / 6 A

 

Relay 2: 250 VAC / 30 VDC / 6 A

 

Adjustable switching point and hysteresis

Zero/Span output calibrated within ±0.025 V

Resistance minimum: 1 kΩ

Current consumption:

 

35 mA + relays (7 mA each) + AZ circuit (20 mA)

 

+ 0–10 V output (10 mA)

 

Conformance

Meets requirements for CE marking:

EMC Directive 2014/30/EU

RoHS Directive 2011/65/EU

LVD Directive: 2014/35/EU

WEEE Directive 2012/19/EU

INTRODUCTION

APPLICATIONS

WARNING

COMPANY WITH

MANAGEMENT SYSTEM

CERTIFIED BY DNV GL

= ISO 9001 = ISO 14001 =

RoHS 2

2011/65/EU

Summary of Contents for DPI Series

Page 1: ...NS Performance Accuracy 1 5 0 7 FS from highest pressure range including general accuracy temperature drift linearity hysteresis and repetition error Can be achieved with span point calibration Long term stability Typical 1 year With autozero 1 Pa Without autozero 8 Pa Thermal effects Temperature compensated across the full spectrum of capability Overpressure Proof pressure 25 kPa Burst pressure 3...

Page 2: ... terminal block s see step 2 3 The device is now ready for configuration WARNING Apply power only after the device is properly wired 1 Select the mounting location duct wall panel 2 Use the device as a template and mark the screw holes 3 Mount with appropriate screws Figure 1b Mounting orientation Figure 1c Application connections 24 V GND 0 10 V Terminal block Terminal block for relays NC COMNO N...

Page 3: ...ct positive pressure to port labeled and negative pressure to port The device is now ready to be used 24 V GND P out Power supply 24 VDC 24 VAC Output 0 10 V V SPAn ZEro rEL1 2 rESP PSEL UnIt Pa kPa mmH2O inchWC mbar Pressure range selection Response time Relay menu s Zero point calibration High point calibration menu rES AdJ High point calibration Reset high point calibration HYS SP dir Relay act...

Page 4: ...eeze to the latest measured value Transmitters equipped with the autozero calibration are virtually maintenance free The seller is obligated to provide a warranty of five years for the deliv ered goods regarding material and manufacturing The warranty period is considered to start on the delivery date of the product If a defect in raw materials or a production flaw is found the seller is obligated...

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